aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
blob: f4f2801be50df10a9aeda150b06ffe0e7e8e7997 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyrightD
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSimulator Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
using System;
using System.Collections.Generic;
using System.Runtime.InteropServices;
using System.Text;
using System.Threading;
using OpenSim.Framework;
using OpenSim.Region.Framework;
using OpenSim.Region.CoreModules;
using Logging = OpenSim.Region.CoreModules.Framework.Statistics.Logging;
using OpenSim.Region.Physics.Manager;
using Nini.Config;
using log4net;
using OpenMetaverse;

// TODOs for BulletSim (for BSScene, BSPrim, BSCharacter and BulletSim)
// Based on material, set density and friction
// More efficient memory usage when passing hull information from BSPrim to BulletSim
// Do attachments need to be handled separately? Need collision events. Do not collide with VolumeDetect
// Implement LockAngularMotion
// Add PID movement operations. What does ScenePresence.MoveToTarget do?
// Check terrain size. 128 or 127?
// Raycast
//
namespace OpenSim.Region.Physics.BulletSPlugin
{
public sealed class BSScene : PhysicsScene, IPhysicsParameters
{
    private static readonly ILog m_log = LogManager.GetLogger(System.Reflection.MethodBase.GetCurrentMethod().DeclaringType);
    private static readonly string LogHeader = "[BULLETS SCENE]";

    // The name of the region we're working for.
    public string RegionName { get; private set; }

    public string BulletSimVersion = "?";

    public Dictionary<uint, BSPhysObject> PhysObjects;
    public BSShapeCollection Shapes;

    // Keeping track of the objects with collisions so we can report begin and end of a collision
    public HashSet<BSPhysObject> ObjectsWithCollisions = new HashSet<BSPhysObject>();
    public HashSet<BSPhysObject> ObjectsWithNoMoreCollisions = new HashSet<BSPhysObject>();
    // Keep track of all the avatars so we can send them a collision event
    //    every tick so OpenSim will update its animation.
    private HashSet<BSPhysObject> m_avatars = new HashSet<BSPhysObject>();

    // List of all the objects that have vehicle properties and should be called
    //    to update each physics step.
    private List<BSPhysObject> m_vehicles = new List<BSPhysObject>();

    // let my minuions use my logger
    public ILog Logger { get { return m_log; } }

    public IMesher mesher;
    // Level of Detail values kept as float because that's what the Meshmerizer wants
    public float MeshLOD { get; private set; }
    public float MeshMegaPrimLOD { get; private set; }
    public float MeshMegaPrimThreshold { get; private set; }
    public float SculptLOD { get; private set; }

    public uint WorldID { get; private set; }
    public BulletSim World { get; private set; }

    // All the constraints that have been allocated in this instance.
    public BSConstraintCollection Constraints { get; private set; }

    // Simulation parameters
    private int m_maxSubSteps;
    private float m_fixedTimeStep;
    private long m_simulationStep = 0;
    public long SimulationStep { get { return m_simulationStep; } }
    private int m_taintsToProcessPerStep;

    public delegate void PreStepAction(float timeStep);
    public event PreStepAction BeforeStep;

    // A value of the time now so all the collision and update routines do not have to get their own
    // Set to 'now' just before all the prims and actors are called for collisions and updates
    public int SimulationNowTime { get; private set; }

    // True if initialized and ready to do simulation steps
    private bool m_initialized = false;

    // Flag which is true when processing taints.
    // Not guaranteed to be correct all the time (don't depend on this) but good for debugging.
    public bool InTaintTime { get; private set; }

    // Pinned memory used to pass step information between managed and unmanaged
    private int m_maxCollisionsPerFrame;
    private CollisionDesc[] m_collisionArray;
    private GCHandle m_collisionArrayPinnedHandle;

    private int m_maxUpdatesPerFrame;
    private EntityProperties[] m_updateArray;
    private GCHandle m_updateArrayPinnedHandle;

    public bool ShouldMeshSculptedPrim { get; private set; }   // cause scuplted prims to get meshed
    public bool ShouldForceSimplePrimMeshing { get; private set; }   // if a cube or sphere, let Bullet do internal shapes
    public bool ShouldUseHullsForPhysicalObjects { get; private set; }   // 'true' if should create hulls for physical objects

    public float PID_D { get; private set; }    // derivative
    public float PID_P { get; private set; }    // proportional

    public const uint TERRAIN_ID = 0;       // OpenSim senses terrain with a localID of zero
    public const uint GROUNDPLANE_ID = 1;
    public const uint CHILDTERRAIN_ID = 2;  // Terrain allocated based on our mega-prim childre start here

    public float SimpleWaterLevel { get; set; }
    public BSTerrainManager TerrainManager { get; private set; }

    public ConfigurationParameters Params
    {
        get { return m_params[0]; }
    }
    public Vector3 DefaultGravity
    {
        get { return new Vector3(0f, 0f, Params.gravity); }
    }
    // Just the Z value of the gravity
    public float DefaultGravityZ
    {
        get { return Params.gravity; }
    }

    public float MaximumObjectMass { get; private set; }

    // When functions in the unmanaged code must be called, it is only
    //   done at a known time just before the simulation step. The taint
    //   system saves all these function calls and executes them in
    //   order before the simulation.
    public delegate void TaintCallback();
    private struct TaintCallbackEntry
    {
        public String ident;
        public TaintCallback callback;
        public TaintCallbackEntry(string i, TaintCallback c)
        {
            ident = i;
            callback = c;
        }
    }
    private Object _taintLock = new Object();   // lock for using the next object
    private List<TaintCallbackEntry> _taintOperations;
    private Dictionary<string, TaintCallbackEntry> _postTaintOperations;
    private List<TaintCallbackEntry> _postStepOperations;

    // A pointer to an instance if this structure is passed to the C++ code
    // Used to pass basic configuration values to the unmanaged code.
    ConfigurationParameters[] m_params;
    GCHandle m_paramsHandle;

    // Handle to the callback used by the unmanaged code to call into the managed code.
    // Used for debug logging.
    // Need to store the handle in a persistant variable so it won't be freed.
    private BulletSimAPI.DebugLogCallback m_DebugLogCallbackHandle;

    // Sometimes you just have to log everything.
    public Logging.LogWriter PhysicsLogging;
    private bool m_physicsLoggingEnabled;
    private string m_physicsLoggingDir;
    private string m_physicsLoggingPrefix;
    private int m_physicsLoggingFileMinutes;
    private bool m_physicsLoggingDoFlush;
    // 'true' of the vehicle code is to log lots of details
    public bool VehicleLoggingEnabled { get; private set; }
    public bool VehiclePhysicalLoggingEnabled { get; private set; }
    public bool VehicleScaleAngularVelocityByTimestep { get; private set; }

    #region Construction and Initialization
    public BSScene(string identifier)
    {
        m_initialized = false;
        // we are passed the name of the region we're working for.
        RegionName = identifier;
    }

    public override void Initialise(IMesher meshmerizer, IConfigSource config)
    {
        mesher = meshmerizer;
        _taintOperations = new List<TaintCallbackEntry>();
        _postTaintOperations = new Dictionary<string, TaintCallbackEntry>();
        _postStepOperations = new List<TaintCallbackEntry>();
        PhysObjects = new Dictionary<uint, BSPhysObject>();
        Shapes = new BSShapeCollection(this);

        // Allocate pinned memory to pass parameters.
        m_params = new ConfigurationParameters[1];
        m_paramsHandle = GCHandle.Alloc(m_params, GCHandleType.Pinned);

        // Set default values for physics parameters plus any overrides from the ini file
        GetInitialParameterValues(config);

        // allocate more pinned memory close to the above in an attempt to get the memory all together
        m_collisionArray = new CollisionDesc[m_maxCollisionsPerFrame];
        m_collisionArrayPinnedHandle = GCHandle.Alloc(m_collisionArray, GCHandleType.Pinned);
        m_updateArray = new EntityProperties[m_maxUpdatesPerFrame];
        m_updateArrayPinnedHandle = GCHandle.Alloc(m_updateArray, GCHandleType.Pinned);

        // Enable very detailed logging.
        // By creating an empty logger when not logging, the log message invocation code
        //     can be left in and every call doesn't have to check for null.
        if (m_physicsLoggingEnabled)
        {
            PhysicsLogging = new Logging.LogWriter(m_physicsLoggingDir, m_physicsLoggingPrefix, m_physicsLoggingFileMinutes);
            PhysicsLogging.ErrorLogger = m_log; // for DEBUG. Let's the logger output error messages.
        }
        else
        {
            PhysicsLogging = new Logging.LogWriter();
        }

        // If Debug logging level, enable logging from the unmanaged code
        m_DebugLogCallbackHandle = null;
        if (m_log.IsDebugEnabled || PhysicsLogging.Enabled)
        {
            m_log.DebugFormat("{0}: Initialize: Setting debug callback for unmanaged code", LogHeader);
            if (PhysicsLogging.Enabled)
                // The handle is saved in a variable to make sure it doesn't get freed after this call
                m_DebugLogCallbackHandle = new BulletSimAPI.DebugLogCallback(BulletLoggerPhysLog);
            else
                m_DebugLogCallbackHandle = new BulletSimAPI.DebugLogCallback(BulletLogger);
        }

        // Get the version of the DLL
        // TODO: this doesn't work yet. Something wrong with marshaling the returned string.
        // BulletSimVersion = BulletSimAPI.GetVersion();
        // m_log.WarnFormat("{0}: BulletSim.dll version='{1}'", LogHeader, BulletSimVersion);

        // The bounding box for the simulated world. The origin is 0,0,0 unless we're
        //    a child in a mega-region.
        // Bullet actually doesn't care about the extents of the simulated
        //    area. It tracks active objects no matter where they are.
        Vector3 worldExtent = new Vector3(Constants.RegionSize, Constants.RegionSize, Constants.RegionHeight);

        // m_log.DebugFormat("{0}: Initialize: Calling BulletSimAPI.Initialize.", LogHeader);
        World = new BulletSim(0, this, BulletSimAPI.Initialize2(worldExtent, m_paramsHandle.AddrOfPinnedObject(),
                                        m_maxCollisionsPerFrame, m_collisionArrayPinnedHandle.AddrOfPinnedObject(),
                                        m_maxUpdatesPerFrame, m_updateArrayPinnedHandle.AddrOfPinnedObject(),
                                        m_DebugLogCallbackHandle));

        Constraints = new BSConstraintCollection(World);

        TerrainManager = new BSTerrainManager(this);
        TerrainManager.CreateInitialGroundPlaneAndTerrain();

        m_log.WarnFormat("{0} Linksets implemented with {1}", LogHeader, (BSLinkset.LinksetImplementation)Params.linksetImplementation);

        InTaintTime = false;
        m_initialized = true;
    }

    // All default parameter values are set here. There should be no values set in the
    // variable definitions.
    private void GetInitialParameterValues(IConfigSource config)
    {
        ConfigurationParameters parms = new ConfigurationParameters();
        m_params[0] = parms;

        SetParameterDefaultValues();

        if (config != null)
        {
            // If there are specifications in the ini file, use those values
            IConfig pConfig = config.Configs["BulletSim"];
            if (pConfig != null)
            {
                SetParameterConfigurationValues(pConfig);

                // Very detailed logging for physics debugging
                m_physicsLoggingEnabled = pConfig.GetBoolean("PhysicsLoggingEnabled", false);
                m_physicsLoggingDir = pConfig.GetString("PhysicsLoggingDir", ".");
                m_physicsLoggingPrefix = pConfig.GetString("PhysicsLoggingPrefix", "physics-%REGIONNAME%-");
                m_physicsLoggingFileMinutes = pConfig.GetInt("PhysicsLoggingFileMinutes", 5);
                m_physicsLoggingDoFlush = pConfig.GetBoolean("PhysicsLoggingDoFlush", false);
                // Very detailed logging for vehicle debugging
                VehicleLoggingEnabled = pConfig.GetBoolean("VehicleLoggingEnabled", false);
                VehiclePhysicalLoggingEnabled = pConfig.GetBoolean("VehiclePhysicalLoggingEnabled", false);

                // Do any replacements in the parameters
                m_physicsLoggingPrefix = m_physicsLoggingPrefix.Replace("%REGIONNAME%", RegionName);
            }

            // The material characteristics.
            BSMaterials.InitializeFromDefaults(Params);
            if (pConfig != null)
            {
                BSMaterials.InitializefromParameters(pConfig);
            }
        }
    }

    // A helper function that handles a true/false parameter and returns the proper float number encoding
    float ParamBoolean(IConfig config, string parmName, float deflt)
    {
        float ret = deflt;
        if (config.Contains(parmName))
        {
            ret = ConfigurationParameters.numericFalse;
            if (config.GetBoolean(parmName, false))
            {
                ret = ConfigurationParameters.numericTrue;
            }
        }
        return ret;
    }

    // Called directly from unmanaged code so don't do much
    private void BulletLogger(string msg)
    {
        m_log.Debug("[BULLETS UNMANAGED]:" + msg);
    }

    // Called directly from unmanaged code so don't do much
    private void BulletLoggerPhysLog(string msg)
    {
        DetailLog("[BULLETS UNMANAGED]:" + msg);
    }

    public override void Dispose()
    {
        // m_log.DebugFormat("{0}: Dispose()", LogHeader);

        // make sure no stepping happens while we're deleting stuff
        m_initialized = false;

        TerrainManager.ReleaseGroundPlaneAndTerrain();

        foreach (KeyValuePair<uint, BSPhysObject> kvp in PhysObjects)
        {
            kvp.Value.Destroy();
        }
        PhysObjects.Clear();

        // Now that the prims are all cleaned up, there should be no constraints left
        if (Constraints != null)
        {
            Constraints.Dispose();
            Constraints = null;
        }

        if (Shapes != null)
        {
            Shapes.Dispose();
            Shapes = null;
        }

        // Anything left in the unmanaged code should be cleaned out
        BulletSimAPI.Shutdown2(World.ptr);

        // Not logging any more
        PhysicsLogging.Close();
    }
    #endregion // Construction and Initialization

    #region Prim and Avatar addition and removal

    public override PhysicsActor AddAvatar(string avName, Vector3 position, Vector3 size, bool isFlying)
    {
        m_log.ErrorFormat("{0}: CALL TO AddAvatar in BSScene. NOT IMPLEMENTED", LogHeader);
        return null;
    }

    public override PhysicsActor AddAvatar(uint localID, string avName, Vector3 position, Vector3 size, bool isFlying)
    {
        // m_log.DebugFormat("{0}: AddAvatar: {1}", LogHeader, avName);

        if (!m_initialized) return null;

        BSCharacter actor = new BSCharacter(localID, avName, this, position, size, isFlying);
        lock (PhysObjects) PhysObjects.Add(localID, actor);

        // TODO: Remove kludge someday.
        // We must generate a collision for avatars whether they collide or not.
        // This is required by OpenSim to update avatar animations, etc.
        lock (m_avatars) m_avatars.Add(actor);

        return actor;
    }

    public override void RemoveAvatar(PhysicsActor actor)
    {
        // m_log.DebugFormat("{0}: RemoveAvatar", LogHeader);

        if (!m_initialized) return;

        BSCharacter bsactor = actor as BSCharacter;
        if (bsactor != null)
        {
            try
            {
                lock (PhysObjects) PhysObjects.Remove(actor.LocalID);
                // Remove kludge someday
                lock (m_avatars) m_avatars.Remove(bsactor);
            }
            catch (Exception e)
            {
                m_log.WarnFormat("{0}: Attempt to remove avatar that is not in physics scene: {1}", LogHeader, e);
            }
            bsactor.Destroy();
            // bsactor.dispose();
        }
    }

    public override void RemovePrim(PhysicsActor prim)
    {
        if (!m_initialized) return;

        BSPrim bsprim = prim as BSPrim;
        if (bsprim != null)
        {
            DetailLog("{0},RemovePrim,call", bsprim.LocalID);
            // m_log.DebugFormat("{0}: RemovePrim. id={1}/{2}", LogHeader, bsprim.Name, bsprim.LocalID);
            try
            {
                lock (PhysObjects) PhysObjects.Remove(bsprim.LocalID);
            }
            catch (Exception e)
            {
                m_log.ErrorFormat("{0}: Attempt to remove prim that is not in physics scene: {1}", LogHeader, e);
            }
            bsprim.Destroy();
            // bsprim.dispose();
        }
        else
        {
            m_log.ErrorFormat("{0}: Attempt to remove prim that is not a BSPrim type.", LogHeader);
        }
    }

    public override PhysicsActor AddPrimShape(string primName, PrimitiveBaseShape pbs, Vector3 position,
                                              Vector3 size, Quaternion rotation, bool isPhysical, uint localID)
    {
        // m_log.DebugFormat("{0}: AddPrimShape2: {1}", LogHeader, primName);

        if (!m_initialized) return null;

        DetailLog("{0},AddPrimShape,call", localID);

        BSPrim prim = new BSPrim(localID, primName, this, position, size, rotation, pbs, isPhysical);
        lock (PhysObjects) PhysObjects.Add(localID, prim);
        return prim;
    }

    // This is a call from the simulator saying that some physical property has been updated.
    // The BulletSim driver senses the changing of relevant properties so this taint
    // information call is not needed.
    public override void AddPhysicsActorTaint(PhysicsActor prim) { }

    #endregion // Prim and Avatar addition and removal

    #region Simulation
    // Simulate one timestep
    public override float Simulate(float timeStep)
    {
        int updatedEntityCount = 0;
        IntPtr updatedEntitiesPtr;
        int collidersCount = 0;
        IntPtr collidersPtr;

        int beforeTime = 0;
        int simTime = 0;

        // prevent simulation until we've been initialized
        if (!m_initialized) return 5.0f;

        // update the prim states while we know the physics engine is not busy
        int numTaints = _taintOperations.Count;
        ProcessTaints();

        // Some of the prims operate with special vehicle properties
        DoPreStepActions(timeStep);

        // the prestep actions might have added taints
        ProcessTaints();

        // step the physical world one interval
        m_simulationStep++;
        int numSubSteps = 0;

        try
        {
            if (VehiclePhysicalLoggingEnabled) DumpVehicles();  // DEBUG
            if (PhysicsLogging.Enabled) beforeTime = Util.EnvironmentTickCount();

            numSubSteps = BulletSimAPI.PhysicsStep2(World.ptr, timeStep, m_maxSubSteps, m_fixedTimeStep,
                        out updatedEntityCount, out updatedEntitiesPtr, out collidersCount, out collidersPtr);

            if (PhysicsLogging.Enabled) simTime = Util.EnvironmentTickCountSubtract(beforeTime);
            DetailLog("{0},Simulate,call, frame={1}, nTaints={2}, simTime={3}, substeps={4}, updates={5}, colliders={6}",
                        DetailLogZero, m_simulationStep, numTaints, simTime, numSubSteps, updatedEntityCount, collidersCount);
            if (VehiclePhysicalLoggingEnabled) DumpVehicles();  // DEBUG
        }
        catch (Exception e)
        {
            m_log.WarnFormat("{0},PhysicsStep Exception: nTaints={1}, substeps={2}, updates={3}, colliders={4}, e={5}",
                        LogHeader, numTaints, numSubSteps, updatedEntityCount, collidersCount, e);
            DetailLog("{0},PhysicsStepException,call, nTaints={1}, substeps={2}, updates={3}, colliders={4}",
                        DetailLogZero, numTaints, numSubSteps, updatedEntityCount, collidersCount);
            updatedEntityCount = 0;
            collidersCount = 0;
        }

        // Don't have to use the pointers passed back since we know it is the same pinned memory we passed in.

        // Get a value for 'now' so all the collision and update routines don't have to get their own.
        SimulationNowTime = Util.EnvironmentTickCount();

        // If there were collisions, process them by sending the event to the prim.
        // Collisions must be processed before updates.
        if (collidersCount > 0)
        {
            for (int ii = 0; ii < collidersCount; ii++)
            {
                uint cA = m_collisionArray[ii].aID;
                uint cB = m_collisionArray[ii].bID;
                Vector3 point = m_collisionArray[ii].point;
                Vector3 normal = m_collisionArray[ii].normal;
                SendCollision(cA, cB, point, normal, 0.01f);
                SendCollision(cB, cA, point, -normal, 0.01f);
            }
        }

        // The above SendCollision's batch up the collisions on the objects.
        //      Now push the collisions into the simulator.
        if (ObjectsWithCollisions.Count > 0)
        {
            foreach (BSPhysObject bsp in ObjectsWithCollisions)
                if (!bsp.SendCollisions())
                {
                    // If the object is done colliding, see that it's removed from the colliding list
                    ObjectsWithNoMoreCollisions.Add(bsp);
                }
        }

        // This is a kludge to get avatar movement updates.
        // The simulator expects collisions for avatars even if there are have been no collisions.
        //    The event updates avatar animations and stuff.
        // If you fix avatar animation updates, remove this overhead and let normal collision processing happen.
        foreach (BSPhysObject bsp in m_avatars)
            if (!ObjectsWithCollisions.Contains(bsp))   // don't call avatars twice
                bsp.SendCollisions();

        // Objects that are done colliding are removed from the ObjectsWithCollisions list.
        // Not done above because it is inside an iteration of ObjectWithCollisions.
        if (ObjectsWithNoMoreCollisions.Count > 0)
        {
            foreach (BSPhysObject po in ObjectsWithNoMoreCollisions)
                ObjectsWithCollisions.Remove(po);
            ObjectsWithNoMoreCollisions.Clear();
        }
        // Done with collisions.

        // If any of the objects had updated properties, tell the object it has been changed by the physics engine
        if (updatedEntityCount > 0)
        {
            for (int ii = 0; ii < updatedEntityCount; ii++)
            {
                EntityProperties entprop = m_updateArray[ii];
                BSPhysObject pobj;
                if (PhysObjects.TryGetValue(entprop.ID, out pobj))
                {
                    pobj.UpdateProperties(entprop);
                }
            }
        }

        ProcessPostStepTaints();

        // This causes the unmanaged code to output ALL the values found in ALL the objects in the world.
        // Only enable this in a limited test world with few objects.
        // BulletSimAPI.DumpAllInfo2(World.ptr);    // DEBUG DEBUG DEBUG

        // The physics engine returns the number of milliseconds it simulated this call.
        // These are summed and normalized to one second and divided by 1000 to give the reported physics FPS.
        // Multiply by 55 to give a nominal frame rate of 55.
        return (float)numSubSteps * m_fixedTimeStep * 1000f * 55f;
    }

    // Something has collided
    private void SendCollision(uint localID, uint collidingWith, Vector3 collidePoint, Vector3 collideNormal, float penetration)
    {
        if (localID <= TerrainManager.HighestTerrainID)
        {
            return;         // don't send collisions to the terrain
        }

        BSPhysObject collider;
        if (!PhysObjects.TryGetValue(localID, out collider))
        {
            // If the object that is colliding cannot be found, just ignore the collision.
            DetailLog("{0},BSScene.SendCollision,colliderNotInObjectList,id={1},with={2}", DetailLogZero, localID, collidingWith);
            return;
        }

        // The terrain is not in the physical object list so 'collidee' can be null when Collide() is called.
        BSPhysObject collidee = null;
        PhysObjects.TryGetValue(collidingWith, out collidee);

        // DetailLog("{0},BSScene.SendCollision,collide,id={1},with={2}", DetailLogZero, localID, collidingWith);

        if (collider.Collide(collidingWith, collidee, collidePoint, collideNormal, penetration))
        {
            // If a collision was posted, remember to send it to the simulator
            ObjectsWithCollisions.Add(collider);
        }

        return;
    }

    #endregion // Simulation

    public override void GetResults() { }

    #region Terrain

    public override void SetTerrain(float[] heightMap) {
        TerrainManager.SetTerrain(heightMap);
    }

    public override void SetWaterLevel(float baseheight)
    {
        SimpleWaterLevel = baseheight;
    }

    public override void DeleteTerrain()
    {
        // m_log.DebugFormat("{0}: DeleteTerrain()", LogHeader);
    }

    // Although no one seems to check this, I do support combining.
    public override bool SupportsCombining()
    {
        return TerrainManager.SupportsCombining();
    }
    // This call says I am a child to region zero in a mega-region. 'pScene' is that
    //    of region zero, 'offset' is my offset from regions zero's origin, and
    //    'extents' is the largest XY that is handled in my region.
    public override void Combine(PhysicsScene pScene, Vector3 offset, Vector3 extents)
    {
        TerrainManager.Combine(pScene, offset, extents);
    }

    // Unhook all the combining that I know about.
    public override void UnCombine(PhysicsScene pScene)
    {
        TerrainManager.UnCombine(pScene);
    }

    #endregion // Terrain

    public override Dictionary<uint, float> GetTopColliders()
    {
        return new Dictionary<uint, float>();
    }

    public override bool IsThreaded { get { return false;  } }

    #region Taints

    // Calls to the PhysicsActors can't directly call into the physics engine
    //       because it might be busy. We delay changes to a known time.
    // We rely on C#'s closure to save and restore the context for the delegate.
    public void TaintedObject(String ident, TaintCallback callback)
    {
        if (!m_initialized) return;

        lock (_taintLock)
        {
            _taintOperations.Add(new TaintCallbackEntry(ident, callback));
        }

        return;
    }

    // Sometimes a potentially tainted operation can be used in and out of taint time.
    // This routine executes the command immediately if in taint-time otherwise it is queued.
    public void TaintedObject(bool inTaintTime, string ident, TaintCallback callback)
    {
        if (inTaintTime)
            callback();
        else
            TaintedObject(ident, callback);
    }

    // When someone tries to change a property on a BSPrim or BSCharacter, the object queues
    // a callback into itself to do the actual property change. That callback is called
    // here just before the physics engine is called to step the simulation.
    public void ProcessTaints()
    {
        InTaintTime = true; // Only used for debugging so locking is not necessary.
        ProcessRegularTaints();
        ProcessPostTaintTaints();
        InTaintTime = false;
    }

    private void ProcessRegularTaints()
    {
        if (_taintOperations.Count > 0)  // save allocating new list if there is nothing to process
        {
            /*
            // Code to limit the number of taints processed per step. Meant to limit step time.
            // Unsure if a good idea as code assumes that taints are done before the step.
            int taintCount = m_taintsToProcessPerStep;
            TaintCallbackEntry oneCallback = new TaintCallbackEntry();
            while (_taintOperations.Count > 0 && taintCount-- > 0)
            {
                bool gotOne = false;
                lock (_taintLock)
                {
                    if (_taintOperations.Count > 0)
                    {
                        oneCallback = _taintOperations[0];
                        _taintOperations.RemoveAt(0);
                        gotOne = true;
                    }
                }
                if (gotOne)
                {
                    try
                    {
                        DetailLog("{0},BSScene.ProcessTaints,doTaint,id={1}", DetailLogZero, oneCallback.ident);
                        oneCallback.callback();
                    }
                    catch (Exception e)
                    {
                        DetailLog("{0},BSScene.ProcessTaints,doTaintException,id={1}", DetailLogZero, oneCallback.ident); // DEBUG DEBUG DEBUG
                        m_log.ErrorFormat("{0}: ProcessTaints: {1}: Exception: {2}", LogHeader, oneCallback.ident, e);
                    }
                }
            }
            if (_taintOperations.Count > 0)
            {
                DetailLog("{0},BSScene.ProcessTaints,leftTaintsOnList,numNotProcessed={1}", DetailLogZero, _taintOperations.Count);
            }
             */

            // swizzle a new list into the list location so we can process what's there
            List<TaintCallbackEntry> oldList;
            lock (_taintLock)
            {
                oldList = _taintOperations;
                _taintOperations = new List<TaintCallbackEntry>();
            }

            foreach (TaintCallbackEntry tcbe in oldList)
            {
                try
                {
                    DetailLog("{0},BSScene.ProcessTaints,doTaint,id={1}", DetailLogZero, tcbe.ident); // DEBUG DEBUG DEBUG
                    tcbe.callback();
                }
                catch (Exception e)
                {
                    m_log.ErrorFormat("{0}: ProcessTaints: {1}: Exception: {2}", LogHeader, tcbe.ident, e);
                }
            }
            oldList.Clear();
        }
    }

    // Schedule an update to happen after all the regular taints are processed.
    // Note that new requests for the same operation ("ident") for the same object ("ID")
    //     will replace any previous operation by the same object.
    public void PostTaintObject(String ident, uint ID, TaintCallback callback)
    {
        string uniqueIdent = ident + "-" + ID.ToString();
        lock (_taintLock)
        {
            _postTaintOperations[uniqueIdent] = new TaintCallbackEntry(uniqueIdent, callback);
        }

        return;
    }

    private void ProcessPostTaintTaints()
    {
        if (_postTaintOperations.Count > 0)
        {
            Dictionary<string, TaintCallbackEntry> oldList;
            lock (_taintLock)
            {
                oldList = _postTaintOperations;
                _postTaintOperations = new Dictionary<string, TaintCallbackEntry>();
            }

            foreach (KeyValuePair<string,TaintCallbackEntry> kvp in oldList)
            {
                try
                {
                    DetailLog("{0},BSScene.ProcessPostTaintTaints,doTaint,id={1}", DetailLogZero, kvp.Key); // DEBUG DEBUG DEBUG
                    kvp.Value.callback();
                }
                catch (Exception e)
                {
                    m_log.ErrorFormat("{0}: ProcessPostTaintTaints: {1}: Exception: {2}", LogHeader, kvp.Key, e);
                }
            }
            oldList.Clear();
        }
    }

    public void PostStepTaintObject(String ident, TaintCallback callback)
    {
        if (!m_initialized) return;

        lock (_taintLock)
        {
            _postStepOperations.Add(new TaintCallbackEntry(ident, callback));
        }

        return;
    }

    private void ProcessPostStepTaints()
    {
        if (_postStepOperations.Count > 0)
        {
            List<TaintCallbackEntry> oldList;
            lock (_taintLock)
            {
                oldList = _postStepOperations;
                _postStepOperations = new List<TaintCallbackEntry>();
            }

            foreach (TaintCallbackEntry tcbe in oldList)
            {
                try
                {
                    DetailLog("{0},BSScene.ProcessPostStepTaints,doTaint,id={1}", DetailLogZero, tcbe.ident); // DEBUG DEBUG DEBUG
                    tcbe.callback();
                }
                catch (Exception e)
                {
                    m_log.ErrorFormat("{0}: ProcessPostStepTaints: {1}: Exception: {2}", LogHeader, tcbe.ident, e);
                }
            }
            oldList.Clear();
        }
    }

    // Only used for debugging. Does not change state of anything so locking is not necessary.
    public bool AssertInTaintTime(string whereFrom)
    {
        if (!InTaintTime)
        {
            DetailLog("{0},BSScene.AssertInTaintTime,NOT IN TAINT TIME,Region={1},Where={2}", DetailLogZero, RegionName, whereFrom);
            m_log.ErrorFormat("{0} NOT IN TAINT TIME!! Region={1}, Where={2}", LogHeader, RegionName, whereFrom);
            Util.PrintCallStack();  // Prints the stack into the DEBUG log file.
        }
        return InTaintTime;
    }

    #endregion // Taints

    #region Vehicles

    public void VehicleInSceneTypeChanged(BSPrim vehic, Vehicle newType)
    {
        RemoveVehiclePrim(vehic);
        if (newType != Vehicle.TYPE_NONE)
        {
           // make it so the scene will call us each tick to do vehicle things
           AddVehiclePrim(vehic);
        }
    }

    // Make so the scene will call this prim for vehicle actions each tick.
    // Safe to call if prim is already in the vehicle list.
    public void AddVehiclePrim(BSPrim vehicle)
    {
        lock (m_vehicles)
        {
            if (!m_vehicles.Contains(vehicle))
            {
                m_vehicles.Add(vehicle);
            }
        }
    }

    // Remove a prim from our list of vehicles.
    // Safe to call if the prim is not in the vehicle list.
    public void RemoveVehiclePrim(BSPrim vehicle)
    {
        lock (m_vehicles)
        {
            if (m_vehicles.Contains(vehicle))
            {
                m_vehicles.Remove(vehicle);
            }
        }
    }

    private void DoPreStepActions(float timeStep)
    {
        ProcessVehicles(timeStep);

        PreStepAction actions = BeforeStep;
        if (actions != null)
            actions(timeStep);

    }

    // Some prims have extra vehicle actions
    // Called at taint time!
    private void ProcessVehicles(float timeStep)
    {
        foreach (BSPhysObject pobj in m_vehicles)
        {
            pobj.StepVehicle(timeStep);
        }
    }
    #endregion Vehicles

    #region INI and command line parameter processing

    delegate void ParamUser(BSScene scene, IConfig conf, string paramName, float val);
    delegate float ParamGet(BSScene scene);
    delegate void ParamSet(BSScene scene, string paramName, uint localID, float val);
    delegate void SetOnObject(BSScene scene, BSPhysObject obj, float val);

    private struct ParameterDefn
    {
        public string name;         // string name of the parameter
        public string desc;         // a short description of what the parameter means
        public float defaultValue;  // default value if not specified anywhere else
        public ParamUser userParam; // get the value from the configuration file
        public ParamGet getter;     // return the current value stored for this parameter
        public ParamSet setter;     // set the current value for this parameter
        public SetOnObject onObject;    // set the value on an object in the physical domain
        public ParameterDefn(string n, string d, float v, ParamUser u, ParamGet g, ParamSet s)
        {
            name = n;
            desc = d;
            defaultValue = v;
            userParam = u;
            getter = g;
            setter = s;
            onObject = null;
        }
        public ParameterDefn(string n, string d, float v, ParamUser u, ParamGet g, ParamSet s, SetOnObject o)
        {
            name = n;
            desc = d;
            defaultValue = v;
            userParam = u;
            getter = g;
            setter = s;
            onObject = o;
        }
    }

    // List of all of the externally visible parameters.
    // For each parameter, this table maps a text name to getter and setters.
    // To add a new externally referencable/settable parameter, add the paramter storage
    //    location somewhere in the program and make an entry in this table with the
    //    getters and setters.
    // It is easiest to find an existing definition and copy it.
    // Parameter values are floats. Booleans are converted to a floating value.
    //
    // A ParameterDefn() takes the following parameters:
    //    -- the text name of the parameter. This is used for console input and ini file.
    //    -- a short text description of the parameter. This shows up in the console listing.
    //    -- a delegate for fetching the parameter from the ini file.
    //          Should handle fetching the right type from the ini file and converting it.
    //    -- a delegate for getting the value as a float
    //    -- a delegate for setting the value from a float
    //    -- an optional delegate to update the value in the world. Most often used to
    //          push the new value to an in-world object.
    //
    // The single letter parameters for the delegates are:
    //    s = BSScene
    //    o = BSPhysObject
    //    p = string parameter name
    //    l = localID of referenced object
    //    v = float value
    //    cf = parameter configuration class (for fetching values from ini file)
    private ParameterDefn[] ParameterDefinitions =
    {
        new ParameterDefn("MeshSculptedPrim", "Whether to create meshes for sculpties",
            ConfigurationParameters.numericTrue,
            (s,cf,p,v) => { s.ShouldMeshSculptedPrim = cf.GetBoolean(p, s.BoolNumeric(v)); },
            (s) => { return s.NumericBool(s.ShouldMeshSculptedPrim); },
            (s,p,l,v) => { s.ShouldMeshSculptedPrim = s.BoolNumeric(v); } ),
        new ParameterDefn("ForceSimplePrimMeshing", "If true, only use primitive meshes for objects",
            ConfigurationParameters.numericFalse,
            (s,cf,p,v) => { s.ShouldForceSimplePrimMeshing = cf.GetBoolean(p, s.BoolNumeric(v)); },
            (s) => { return s.NumericBool(s.ShouldForceSimplePrimMeshing); },
            (s,p,l,v) => { s.ShouldForceSimplePrimMeshing = s.BoolNumeric(v); } ),
        new ParameterDefn("UseHullsForPhysicalObjects", "If true, create hulls for physical objects",
            ConfigurationParameters.numericTrue,
            (s,cf,p,v) => { s.ShouldUseHullsForPhysicalObjects = cf.GetBoolean(p, s.BoolNumeric(v)); },
            (s) => { return s.NumericBool(s.ShouldUseHullsForPhysicalObjects); },
            (s,p,l,v) => { s.ShouldUseHullsForPhysicalObjects = s.BoolNumeric(v); } ),

        new ParameterDefn("MeshLevelOfDetail", "Level of detail to render meshes (32, 16, 8 or 4. 32=most detailed)",
            8f,
            (s,cf,p,v) => { s.MeshLOD = (float)cf.GetInt(p, (int)v); },
            (s) => { return s.MeshLOD; },
            (s,p,l,v) => { s.MeshLOD = v; } ),
        new ParameterDefn("MeshLevelOfDetailMegaPrim", "Level of detail to render meshes larger than threshold meters",
            16f,
            (s,cf,p,v) => { s.MeshMegaPrimLOD = (float)cf.GetInt(p, (int)v); },
            (s) => { return s.MeshMegaPrimLOD; },
            (s,p,l,v) => { s.MeshMegaPrimLOD = v; } ),
        new ParameterDefn("MeshLevelOfDetailMegaPrimThreshold", "Size (in meters) of a mesh before using MeshMegaPrimLOD",
            10f,
            (s,cf,p,v) => { s.MeshMegaPrimThreshold = (float)cf.GetInt(p, (int)v); },
            (s) => { return s.MeshMegaPrimThreshold; },
            (s,p,l,v) => { s.MeshMegaPrimThreshold = v; } ),
        new ParameterDefn("SculptLevelOfDetail", "Level of detail to render sculpties (32, 16, 8 or 4. 32=most detailed)",
            32f,
            (s,cf,p,v) => { s.SculptLOD = (float)cf.GetInt(p, (int)v); },
            (s) => { return s.SculptLOD; },
            (s,p,l,v) => { s.SculptLOD = v; } ),

        new ParameterDefn("MaxSubStep", "In simulation step, maximum number of substeps",
            10f,
            (s,cf,p,v) => { s.m_maxSubSteps = cf.GetInt(p, (int)v); },
            (s) => { return (float)s.m_maxSubSteps; },
            (s,p,l,v) => { s.m_maxSubSteps = (int)v; } ),
        new ParameterDefn("FixedTimeStep", "In simulation step, seconds of one substep (1/60)",
            1f / 60f,
            (s,cf,p,v) => { s.m_fixedTimeStep = cf.GetFloat(p, v); },
            (s) => { return (float)s.m_fixedTimeStep; },
            (s,p,l,v) => { s.m_fixedTimeStep = v; } ),
        new ParameterDefn("MaxCollisionsPerFrame", "Max collisions returned at end of each frame",
            2048f,
            (s,cf,p,v) => { s.m_maxCollisionsPerFrame = cf.GetInt(p, (int)v); },
            (s) => { return (float)s.m_maxCollisionsPerFrame; },
            (s,p,l,v) => { s.m_maxCollisionsPerFrame = (int)v; } ),
        new ParameterDefn("MaxUpdatesPerFrame", "Max updates returned at end of each frame",
            8000f,
            (s,cf,p,v) => { s.m_maxUpdatesPerFrame = cf.GetInt(p, (int)v); },
            (s) => { return (float)s.m_maxUpdatesPerFrame; },
            (s,p,l,v) => { s.m_maxUpdatesPerFrame = (int)v; } ),
        new ParameterDefn("MaxTaintsToProcessPerStep", "Number of update taints to process before each simulation step",
            500f,
            (s,cf,p,v) => { s.m_taintsToProcessPerStep = cf.GetInt(p, (int)v); },
            (s) => { return (float)s.m_taintsToProcessPerStep; },
            (s,p,l,v) => { s.m_taintsToProcessPerStep = (int)v; } ),
        new ParameterDefn("MaxObjectMass", "Maximum object mass (10000.01)",
            10000.01f,
            (s,cf,p,v) => { s.MaximumObjectMass = cf.GetFloat(p, v); },
            (s) => { return (float)s.MaximumObjectMass; },
            (s,p,l,v) => { s.MaximumObjectMass = v; } ),

        new ParameterDefn("PID_D", "Derivitive factor for motion smoothing",
            2200f,
            (s,cf,p,v) => { s.PID_D = cf.GetFloat(p, v); },
            (s) => { return (float)s.PID_D; },
            (s,p,l,v) => { s.PID_D = v; } ),
        new ParameterDefn("PID_P", "Parameteric factor for motion smoothing",
            900f,
            (s,cf,p,v) => { s.PID_P = cf.GetFloat(p, v); },
            (s) => { return (float)s.PID_P; },
            (s,p,l,v) => { s.PID_P = v; } ),

        new ParameterDefn("DefaultFriction", "Friction factor used on new objects",
            0.2f,
            (s,cf,p,v) => { s.m_params[0].defaultFriction = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].defaultFriction; },
            (s,p,l,v) => { s.m_params[0].defaultFriction = v; } ),
        new ParameterDefn("DefaultDensity", "Density for new objects" ,
            10.000006836f,  // Aluminum g/cm3
            (s,cf,p,v) => { s.m_params[0].defaultDensity = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].defaultDensity; },
            (s,p,l,v) => { s.m_params[0].defaultDensity = v; } ),
        new ParameterDefn("DefaultRestitution", "Bouncyness of an object" ,
            0f,
            (s,cf,p,v) => { s.m_params[0].defaultRestitution = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].defaultRestitution; },
            (s,p,l,v) => { s.m_params[0].defaultRestitution = v; } ),
        new ParameterDefn("CollisionMargin", "Margin around objects before collisions are calculated (must be zero!)",
            0.04f,
            (s,cf,p,v) => { s.m_params[0].collisionMargin = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].collisionMargin; },
            (s,p,l,v) => { s.m_params[0].collisionMargin = v; } ),
        new ParameterDefn("Gravity", "Vertical force of gravity (negative means down)",
            -9.80665f,
            (s,cf,p,v) => { s.m_params[0].gravity = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].gravity; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].gravity, p, PhysParameterEntry.APPLY_TO_NONE, v); },
            (s,o,v) => { BulletSimAPI.SetGravity2(s.World.ptr, new Vector3(0f,0f,v)); } ),


        new ParameterDefn("LinearDamping", "Factor to damp linear movement per second (0.0 - 1.0)",
            0f,
            (s,cf,p,v) => { s.m_params[0].linearDamping = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].linearDamping; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].linearDamping, p, l, v); },
            (s,o,v) => { BulletSimAPI.SetDamping2(o.PhysBody.ptr, v, s.m_params[0].angularDamping); } ),
        new ParameterDefn("AngularDamping", "Factor to damp angular movement per second (0.0 - 1.0)",
            0f,
            (s,cf,p,v) => { s.m_params[0].angularDamping = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].angularDamping; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].angularDamping, p, l, v); },
            (s,o,v) => { BulletSimAPI.SetDamping2(o.PhysBody.ptr, s.m_params[0].linearDamping, v); } ),
        new ParameterDefn("DeactivationTime", "Seconds before considering an object potentially static",
            0.2f,
            (s,cf,p,v) => { s.m_params[0].deactivationTime = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].deactivationTime; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].deactivationTime, p, l, v); },
            (s,o,v) => { BulletSimAPI.SetDeactivationTime2(o.PhysBody.ptr, v); } ),
        new ParameterDefn("LinearSleepingThreshold", "Seconds to measure linear movement before considering static",
            0.8f,
            (s,cf,p,v) => { s.m_params[0].linearSleepingThreshold = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].linearSleepingThreshold; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].linearSleepingThreshold, p, l, v); },
            (s,o,v) => { BulletSimAPI.SetSleepingThresholds2(o.PhysBody.ptr, v, v); } ),
        new ParameterDefn("AngularSleepingThreshold", "Seconds to measure angular movement before considering static",
            1.0f,
            (s,cf,p,v) => { s.m_params[0].angularSleepingThreshold = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].angularSleepingThreshold; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].angularSleepingThreshold, p, l, v); },
            (s,o,v) => { BulletSimAPI.SetSleepingThresholds2(o.PhysBody.ptr, v, v); } ),
        new ParameterDefn("CcdMotionThreshold", "Continuious collision detection threshold (0 means no CCD)" ,
            0f,     // set to zero to disable
            (s,cf,p,v) => { s.m_params[0].ccdMotionThreshold = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].ccdMotionThreshold; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].ccdMotionThreshold, p, l, v); },
            (s,o,v) => { BulletSimAPI.SetCcdMotionThreshold2(o.PhysBody.ptr, v); } ),
        new ParameterDefn("CcdSweptSphereRadius", "Continuious collision detection test radius" ,
            0f,
            (s,cf,p,v) => { s.m_params[0].ccdSweptSphereRadius = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].ccdSweptSphereRadius; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].ccdSweptSphereRadius, p, l, v); },
            (s,o,v) => { BulletSimAPI.SetCcdSweptSphereRadius2(o.PhysBody.ptr, v); } ),
        new ParameterDefn("ContactProcessingThreshold", "Distance between contacts before doing collision check" ,
            0.1f,
            (s,cf,p,v) => { s.m_params[0].contactProcessingThreshold = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].contactProcessingThreshold; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].contactProcessingThreshold, p, l, v); },
            (s,o,v) => { BulletSimAPI.SetContactProcessingThreshold2(o.PhysBody.ptr, v); } ),

	    new ParameterDefn("TerrainImplementation", "Type of shape to use for terrain (0=heightmap, 1=mesh)",
            (float)BSTerrainPhys.TerrainImplementation.Mesh,
            (s,cf,p,v) => { s.m_params[0].terrainImplementation = cf.GetFloat(p,v); },
            (s) => { return s.m_params[0].terrainImplementation; },
            (s,p,l,v) => { s.m_params[0].terrainImplementation = v; } ),
        new ParameterDefn("TerrainFriction", "Factor to reduce movement against terrain surface" ,
            0.3f,
            (s,cf,p,v) => { s.m_params[0].terrainFriction = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].terrainFriction; },
            (s,p,l,v) => { s.m_params[0].terrainFriction = v;  /* TODO: set on real terrain */} ),
        new ParameterDefn("TerrainHitFraction", "Distance to measure hit collisions" ,
            0.8f,
            (s,cf,p,v) => { s.m_params[0].terrainHitFraction = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].terrainHitFraction; },
            (s,p,l,v) => { s.m_params[0].terrainHitFraction = v; /* TODO: set on real terrain */ } ),
        new ParameterDefn("TerrainRestitution", "Bouncyness" ,
            0f,
            (s,cf,p,v) => { s.m_params[0].terrainRestitution = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].terrainRestitution; },
            (s,p,l,v) => { s.m_params[0].terrainRestitution = v;  /* TODO: set on real terrain */ } ),
        new ParameterDefn("TerrainCollisionMargin", "Margin where collision checking starts" ,
            0.04f,
            (s,cf,p,v) => { s.m_params[0].terrainCollisionMargin = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].terrainCollisionMargin; },
            (s,p,l,v) => { s.m_params[0].terrainCollisionMargin = v;  /* TODO: set on real terrain */ } ),

        new ParameterDefn("AvatarFriction", "Factor to reduce movement against an avatar. Changed on avatar recreation.",
            0.2f,
            (s,cf,p,v) => { s.m_params[0].avatarFriction = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].avatarFriction; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarFriction, p, l, v); } ),
        new ParameterDefn("AvatarStandingFriction", "Avatar friction when standing. Changed on avatar recreation.",
            10.0f,
            (s,cf,p,v) => { s.m_params[0].avatarStandingFriction = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].avatarStandingFriction; },
            (s,p,l,v) => { s.m_params[0].avatarStandingFriction = v; } ),
        new ParameterDefn("AvatarDensity", "Density of an avatar. Changed on avatar recreation.",
            60f,
            (s,cf,p,v) => { s.m_params[0].avatarDensity = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].avatarDensity; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarDensity, p, l, v); } ),
        new ParameterDefn("AvatarRestitution", "Bouncyness. Changed on avatar recreation.",
            0f,
            (s,cf,p,v) => { s.m_params[0].avatarRestitution = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].avatarRestitution; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarRestitution, p, l, v); } ),
        new ParameterDefn("AvatarCapsuleWidth", "The distance between the sides of the avatar capsule",
            0.6f,
            (s,cf,p,v) => { s.m_params[0].avatarCapsuleWidth = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].avatarCapsuleWidth; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarCapsuleWidth, p, l, v); } ),
        new ParameterDefn("AvatarCapsuleDepth", "The distance between the front and back of the avatar capsule",
            0.45f,
            (s,cf,p,v) => { s.m_params[0].avatarCapsuleDepth = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].avatarCapsuleDepth; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarCapsuleDepth, p, l, v); } ),
        new ParameterDefn("AvatarCapsuleHeight", "Default height of space around avatar",
            1.5f,
            (s,cf,p,v) => { s.m_params[0].avatarCapsuleHeight = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].avatarCapsuleHeight; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarCapsuleHeight, p, l, v); } ),
	    new ParameterDefn("AvatarContactProcessingThreshold", "Distance from capsule to check for collisions",
            0.1f,
            (s,cf,p,v) => { s.m_params[0].avatarContactProcessingThreshold = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].avatarContactProcessingThreshold; },
            (s,p,l,v) => { s.UpdateParameterObject(ref s.m_params[0].avatarContactProcessingThreshold, p, l, v); } ),

        new ParameterDefn("VehicleAngularDamping", "Factor to damp vehicle angular movement per second (0.0 - 1.0)",
            0.95f,
            (s,cf,p,v) => { s.m_params[0].vehicleAngularDamping = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].vehicleAngularDamping; },
            (s,p,l,v) => { s.m_params[0].vehicleAngularDamping = v; } ),
        new ParameterDefn("VehicleScaleAngularVelocityByTimestep", "If true, scale angular turning by timestep",
            ConfigurationParameters.numericFalse,
            (s,cf,p,v) => { s.VehicleScaleAngularVelocityByTimestep = cf.GetBoolean(p, s.BoolNumeric(v)); },
            (s) => { return s.NumericBool(s.VehicleScaleAngularVelocityByTimestep); },
            (s,p,l,v) => { s.VehicleScaleAngularVelocityByTimestep = s.BoolNumeric(v); } ),

	    new ParameterDefn("MaxPersistantManifoldPoolSize", "Number of manifolds pooled (0 means default of 4096)",
            0f,
            (s,cf,p,v) => { s.m_params[0].maxPersistantManifoldPoolSize = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].maxPersistantManifoldPoolSize; },
            (s,p,l,v) => { s.m_params[0].maxPersistantManifoldPoolSize = v; } ),
	    new ParameterDefn("MaxCollisionAlgorithmPoolSize", "Number of collisions pooled (0 means default of 4096)",
            0f,
            (s,cf,p,v) => { s.m_params[0].maxCollisionAlgorithmPoolSize = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].maxCollisionAlgorithmPoolSize; },
            (s,p,l,v) => { s.m_params[0].maxCollisionAlgorithmPoolSize = v; } ),
	    new ParameterDefn("ShouldDisableContactPoolDynamicAllocation", "Enable to allow large changes in object count",
            ConfigurationParameters.numericFalse,
            (s,cf,p,v) => { s.m_params[0].shouldDisableContactPoolDynamicAllocation = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
            (s) => { return s.m_params[0].shouldDisableContactPoolDynamicAllocation; },
            (s,p,l,v) => { s.m_params[0].shouldDisableContactPoolDynamicAllocation = v; } ),
	    new ParameterDefn("ShouldForceUpdateAllAabbs", "Enable to recomputer AABBs every simulator step",
            ConfigurationParameters.numericFalse,
            (s,cf,p,v) => { s.m_params[0].shouldForceUpdateAllAabbs = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
            (s) => { return s.m_params[0].shouldForceUpdateAllAabbs; },
            (s,p,l,v) => { s.m_params[0].shouldForceUpdateAllAabbs = v; } ),
	    new ParameterDefn("ShouldRandomizeSolverOrder", "Enable for slightly better stacking interaction",
            ConfigurationParameters.numericTrue,
            (s,cf,p,v) => { s.m_params[0].shouldRandomizeSolverOrder = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
            (s) => { return s.m_params[0].shouldRandomizeSolverOrder; },
            (s,p,l,v) => { s.m_params[0].shouldRandomizeSolverOrder = v; } ),
	    new ParameterDefn("ShouldSplitSimulationIslands", "Enable splitting active object scanning islands",
            ConfigurationParameters.numericTrue,
            (s,cf,p,v) => { s.m_params[0].shouldSplitSimulationIslands = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
            (s) => { return s.m_params[0].shouldSplitSimulationIslands; },
            (s,p,l,v) => { s.m_params[0].shouldSplitSimulationIslands = v; } ),
	    new ParameterDefn("ShouldEnableFrictionCaching", "Enable friction computation caching",
            ConfigurationParameters.numericFalse,
            (s,cf,p,v) => { s.m_params[0].shouldEnableFrictionCaching = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
            (s) => { return s.m_params[0].shouldEnableFrictionCaching; },
            (s,p,l,v) => { s.m_params[0].shouldEnableFrictionCaching = v; } ),
	    new ParameterDefn("NumberOfSolverIterations", "Number of internal iterations (0 means default)",
            0f,     // zero says use Bullet default
            (s,cf,p,v) => { s.m_params[0].numberOfSolverIterations = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].numberOfSolverIterations; },
            (s,p,l,v) => { s.m_params[0].numberOfSolverIterations = v; } ),

	    new ParameterDefn("LinksetImplementation", "Type of linkset implementation (0=Constraint, 1=Compound, 2=Manual)",
            (float)BSLinkset.LinksetImplementation.Compound,
            (s,cf,p,v) => { s.m_params[0].linksetImplementation = cf.GetFloat(p,v); },
            (s) => { return s.m_params[0].linksetImplementation; },
            (s,p,l,v) => { s.m_params[0].linksetImplementation = v; } ),
	    new ParameterDefn("LinkConstraintUseFrameOffset", "For linksets built with constraints, enable frame offsetFor linksets built with constraints, enable frame offset.",
            ConfigurationParameters.numericFalse,
            (s,cf,p,v) => { s.m_params[0].linkConstraintUseFrameOffset = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
            (s) => { return s.m_params[0].linkConstraintUseFrameOffset; },
            (s,p,l,v) => { s.m_params[0].linkConstraintUseFrameOffset = v; } ),
	    new ParameterDefn("LinkConstraintEnableTransMotor", "Whether to enable translational motor on linkset constraints",
            ConfigurationParameters.numericTrue,
            (s,cf,p,v) => { s.m_params[0].linkConstraintEnableTransMotor = s.NumericBool(cf.GetBoolean(p, s.BoolNumeric(v))); },
            (s) => { return s.m_params[0].linkConstraintEnableTransMotor; },
            (s,p,l,v) => { s.m_params[0].linkConstraintEnableTransMotor = v; } ),
	    new ParameterDefn("LinkConstraintTransMotorMaxVel", "Maximum velocity to be applied by translational motor in linkset constraints",
            5.0f,
            (s,cf,p,v) => { s.m_params[0].linkConstraintTransMotorMaxVel = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].linkConstraintTransMotorMaxVel; },
            (s,p,l,v) => { s.m_params[0].linkConstraintTransMotorMaxVel = v; } ),
	    new ParameterDefn("LinkConstraintTransMotorMaxForce", "Maximum force to be applied by translational motor in linkset constraints",
            0.1f,
            (s,cf,p,v) => { s.m_params[0].linkConstraintTransMotorMaxForce = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].linkConstraintTransMotorMaxForce; },
            (s,p,l,v) => { s.m_params[0].linkConstraintTransMotorMaxForce = v; } ),
	    new ParameterDefn("LinkConstraintCFM", "Amount constraint can be violated. 0=no violation, 1=infinite. Default=0.1",
            0.1f,
            (s,cf,p,v) => { s.m_params[0].linkConstraintCFM = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].linkConstraintCFM; },
            (s,p,l,v) => { s.m_params[0].linkConstraintCFM = v; } ),
	    new ParameterDefn("LinkConstraintERP", "Amount constraint is corrected each tick. 0=none, 1=all. Default = 0.2",
            0.1f,
            (s,cf,p,v) => { s.m_params[0].linkConstraintERP = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].linkConstraintERP; },
            (s,p,l,v) => { s.m_params[0].linkConstraintERP = v; } ),
	    new ParameterDefn("LinkConstraintSolverIterations", "Number of solver iterations when computing constraint. (0 = Bullet default)",
            40,
            (s,cf,p,v) => { s.m_params[0].linkConstraintSolverIterations = cf.GetFloat(p, v); },
            (s) => { return s.m_params[0].linkConstraintSolverIterations; },
            (s,p,l,v) => { s.m_params[0].linkConstraintSolverIterations = v; } ),

        new ParameterDefn("LogPhysicsStatisticsFrames", "Frames between outputting detailed phys stats. (0 is off)",
            0f,
            (s,cf,p,v) => { s.m_params[0].physicsLoggingFrames = cf.GetInt(p, (int)v); },
            (s) => { return (float)s.m_params[0].physicsLoggingFrames; },
            (s,p,l,v) => { s.m_params[0].physicsLoggingFrames = (int)v; } ),
    };

    // Convert a boolean to our numeric true and false values
    public float NumericBool(bool b)
    {
        return (b ? ConfigurationParameters.numericTrue : ConfigurationParameters.numericFalse);
    }

    // Convert numeric true and false values to a boolean
    public bool BoolNumeric(float b)
    {
        return (b == ConfigurationParameters.numericTrue ? true : false);
    }

    // Search through the parameter definitions and return the matching
    //    ParameterDefn structure.
    // Case does not matter as names are compared after converting to lower case.
    // Returns 'false' if the parameter is not found.
    private bool TryGetParameter(string paramName, out ParameterDefn defn)
    {
        bool ret = false;
        ParameterDefn foundDefn = new ParameterDefn();
        string pName = paramName.ToLower();

        foreach (ParameterDefn parm in ParameterDefinitions)
        {
            if (pName == parm.name.ToLower())
            {
                foundDefn = parm;
                ret = true;
                break;
            }
        }
        defn = foundDefn;
        return ret;
    }

    // Pass through the settable parameters and set the default values
    private void SetParameterDefaultValues()
    {
        foreach (ParameterDefn parm in ParameterDefinitions)
        {
            parm.setter(this, parm.name, PhysParameterEntry.APPLY_TO_NONE, parm.defaultValue);
        }
    }

    // Get user set values out of the ini file.
    private void SetParameterConfigurationValues(IConfig cfg)
    {
        foreach (ParameterDefn parm in ParameterDefinitions)
        {
            parm.userParam(this, cfg, parm.name, parm.defaultValue);
        }
    }

    private PhysParameterEntry[] SettableParameters = new PhysParameterEntry[1];

    // This creates an array in the correct format for returning the list of
    //    parameters. This is used by the 'list' option of the 'physics' command.
    private void BuildParameterTable()
    {
        if (SettableParameters.Length < ParameterDefinitions.Length)
        {
            List<PhysParameterEntry> entries = new List<PhysParameterEntry>();
            for (int ii = 0; ii < ParameterDefinitions.Length; ii++)
            {
                ParameterDefn pd = ParameterDefinitions[ii];
                entries.Add(new PhysParameterEntry(pd.name, pd.desc));
            }

            // make the list in alphabetical order for estetic reasons
            entries.Sort(delegate(PhysParameterEntry ppe1, PhysParameterEntry ppe2)
            {
                return ppe1.name.CompareTo(ppe2.name);
            });

            SettableParameters = entries.ToArray();
        }
    }


    #region IPhysicsParameters
    // Get the list of parameters this physics engine supports
    public PhysParameterEntry[] GetParameterList()
    {
        BuildParameterTable();
        return SettableParameters;
    }

    // Set parameter on a specific or all instances.
    // Return 'false' if not able to set the parameter.
    // Setting the value in the m_params block will change the value the physics engine
    //   will use the next time since it's pinned and shared memory.
    // Some of the values require calling into the physics engine to get the new
    //   value activated ('terrainFriction' for instance).
    public bool SetPhysicsParameter(string parm, float val, uint localID)
    {
        bool ret = false;
        ParameterDefn theParam;
        if (TryGetParameter(parm, out theParam))
        {
            theParam.setter(this, parm, localID, val);
            ret = true;
        }
        return ret;
    }

    // update all the localIDs specified
    // If the local ID is APPLY_TO_NONE, just change the default value
    // If the localID is APPLY_TO_ALL change the default value and apply the new value to all the lIDs
    // If the localID is a specific object, apply the parameter change to only that object
    private void UpdateParameterObject(ref float defaultLoc, string parm, uint localID, float val)
    {
        List<uint> objectIDs = new List<uint>();
        switch (localID)
        {
            case PhysParameterEntry.APPLY_TO_NONE:
                defaultLoc = val;   // setting only the default value
                // This will cause a call into the physical world if some operation is specified (SetOnObject).
                objectIDs.Add(TERRAIN_ID);
                TaintedUpdateParameter(parm, objectIDs, val);
                break;
            case PhysParameterEntry.APPLY_TO_ALL:
                defaultLoc = val;  // setting ALL also sets the default value
                lock (PhysObjects) objectIDs = new List<uint>(PhysObjects.Keys);
                TaintedUpdateParameter(parm, objectIDs, val);
                break;
            default:
                // setting only one localID
                objectIDs.Add(localID);
                TaintedUpdateParameter(parm, objectIDs, val);
                break;
        }
    }

    // schedule the actual updating of the paramter to when the phys engine is not busy
    private void TaintedUpdateParameter(string parm, List<uint> lIDs, float val)
    {
        float xval = val;
        List<uint> xlIDs = lIDs;
        string xparm = parm;
        TaintedObject("BSScene.UpdateParameterSet", delegate() {
            ParameterDefn thisParam;
            if (TryGetParameter(xparm, out thisParam))
            {
                if (thisParam.onObject != null)
                {
                    foreach (uint lID in xlIDs)
                    {
                        BSPhysObject theObject = null;
                        PhysObjects.TryGetValue(lID, out theObject);
                        thisParam.onObject(this, theObject, xval);
                    }
                }
            }
        });
    }

    // Get parameter.
    // Return 'false' if not able to get the parameter.
    public bool GetPhysicsParameter(string parm, out float value)
    {
        float val = 0f;
        bool ret = false;
        ParameterDefn theParam;
        if (TryGetParameter(parm, out theParam))
        {
            val = theParam.getter(this);
            ret = true;
        }
        value = val;
        return ret;
    }

    #endregion IPhysicsParameters

    #endregion Runtime settable parameters

    // Debugging routine for dumping detailed physical information for vehicle prims
    private void DumpVehicles()
    {
        foreach (BSPrim prim in m_vehicles)
        {
            BulletSimAPI.DumpRigidBody2(World.ptr, prim.PhysBody.ptr);
            BulletSimAPI.DumpCollisionShape2(World.ptr, prim.PhysShape.ptr);
        }
    }

    // Invoke the detailed logger and output something if it's enabled.
    public void DetailLog(string msg, params Object[] args)
    {
        PhysicsLogging.Write(msg, args);
        // Add the Flush() if debugging crashes. Gets all the messages written out.
        if (m_physicsLoggingDoFlush) PhysicsLogging.Flush();
    }
    // Used to fill in the LocalID when there isn't one. It's the correct number of characters.
    public const string DetailLogZero = "0000000000";

}
}