aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
blob: 68a153ec65b9d3f365b5c432e30ce1991383a253 (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
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
/*
 * 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.
 */

// Uncomment this it enable code to do all shape an body memory management
//    in the C# code.
#define CSHARP_BODY_MANAGEMENT

using System;
using System.Reflection;
using System.Collections.Generic;
using System.Xml;
using log4net;
using OMV = OpenMetaverse;
using OpenSim.Framework;
using OpenSim.Region.Physics.Manager;
using OpenSim.Region.Physics.ConvexDecompositionDotNet;

namespace OpenSim.Region.Physics.BulletSPlugin
{

    [Serializable]
public sealed class BSPrim : BSPhysObject
{
    private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);
    private static readonly string LogHeader = "[BULLETS PRIM]";

    private IMesh _mesh;
    private PrimitiveBaseShape _pbs;
    private ShapeData.PhysicsShapeType _shapeType;
    private ulong _meshKey;
    private ulong _hullKey;
    private List<ConvexResult> _hulls;

    // _size is what the user passed. _scale is what we pass to the physics engine with the mesh.
    // Often _scale is unity because the meshmerizer will apply _size when creating the mesh.
    private OMV.Vector3 _size;  // the multiplier for each mesh dimension as passed by the user
    private OMV.Vector3 _scale; // the multiplier for each mesh dimension for the mesh as created by the meshmerizer

    private bool _stopped;
    private bool _grabbed;
    private bool _isSelected;
    private bool _isVolumeDetect;
    private OMV.Vector3 _position;
    private float _mass;    // the mass of this object
    private float _density;
    private OMV.Vector3 _force;
    private OMV.Vector3 _velocity;
    private OMV.Vector3 _torque;
    private float _collisionScore;
    private OMV.Vector3 _acceleration;
    private OMV.Quaternion _orientation;
    private int _physicsActorType;
    private bool _isPhysical;
    private bool _flying;
    private float _friction;
    private float _restitution;
    private bool _setAlwaysRun;
    private bool _throttleUpdates;
    private bool _isColliding;
    private bool _collidingGround;
    private bool _collidingObj;
    private bool _floatOnWater;
    private OMV.Vector3 _rotationalVelocity;
    private bool _kinematic;
    private float _buoyancy;

    private BSDynamics _vehicle;

    private OMV.Vector3 _PIDTarget;
    private bool _usePID;
    private float _PIDTau;
    private bool _useHoverPID;
    private float _PIDHoverHeight;
    private PIDHoverType _PIDHoverType;
    private float _PIDHoverTao;

    public BSPrim(uint localID, String primName, BSScene parent_scene, OMV.Vector3 pos, OMV.Vector3 size,
                       OMV.Quaternion rotation, PrimitiveBaseShape pbs, bool pisPhysical)
    {
        // m_log.DebugFormat("{0}: BSPrim creation of {1}, id={2}", LogHeader, primName, localID);
        base.BaseInitialize(parent_scene, localID, primName, "BSPrim");
        _physicsActorType = (int)ActorTypes.Prim;
        _position = pos;
        _size = size;
        _scale = new OMV.Vector3(1f, 1f, 1f);   // the scale will be set by CreateGeom depending on object type
        _orientation = rotation;
        _buoyancy = 1f;
        _velocity = OMV.Vector3.Zero;
        _rotationalVelocity = OMV.Vector3.Zero;
        _hullKey = 0;
        _meshKey = 0;
        _pbs = pbs;
        _isPhysical = pisPhysical;
        _isVolumeDetect = false;
        _friction = PhysicsScene.Params.defaultFriction;  // TODO: compute based on object material
        _density = PhysicsScene.Params.defaultDensity;    // TODO: compute based on object material
        _restitution = PhysicsScene.Params.defaultRestitution;
        _vehicle = new BSDynamics(PhysicsScene, this);            // add vehicleness
        _mass = CalculateMass();

        // No body or shape yet
        BSBody = new BulletBody(LocalID, IntPtr.Zero);
        BSShape = new BulletShape(IntPtr.Zero);

        DetailLog("{0},BSPrim.constructor,call", LocalID);
        // do the actual object creation at taint time
        PhysicsScene.TaintedObject("BSPrim.create", delegate()
        {
            CreateGeomAndObject(true);

            CurrentCollisionFlags = BulletSimAPI.GetCollisionFlags2(BSBody.ptr);
        });
    }

    // called when this prim is being destroyed and we should free all the resources
    public override void Destroy()
    {
        // m_log.DebugFormat("{0}: Destroy, id={1}", LogHeader, LocalID);

        // Undo any links between me and any other object
        BSPhysObject parentBefore = Linkset.LinksetRoot;
        int childrenBefore = Linkset.NumberOfChildren;

        Linkset = Linkset.RemoveMeFromLinkset(this);

        DetailLog("{0},BSPrim.Destroy,call,parentBefore={1},childrenBefore={2},parentAfter={3},childrenAfter={4}",
            LocalID, parentBefore.LocalID, childrenBefore, Linkset.LinksetRoot.LocalID, Linkset.NumberOfChildren);

        // Undo any vehicle properties
        this.VehicleType = (int)Vehicle.TYPE_NONE;

        PhysicsScene.TaintedObject("BSPrim.destroy", delegate()
        {
            DetailLog("{0},BSPrim.Destroy,taint,", LocalID);
            // everything in the C# world will get garbage collected. Tell the C++ world to free stuff.
            BulletSimAPI.DestroyObject(PhysicsScene.WorldID, LocalID);
        });
    }
    
    public override bool Stopped { 
        get { return _stopped; } 
    }
    public override OMV.Vector3 Size { 
        get { return _size; } 
        set {
            _size = value;
            PhysicsScene.TaintedObject("BSPrim.setSize", delegate()
            {
                _mass = CalculateMass();   // changing size changes the mass
                // Since _size changed, the mesh needs to be rebuilt. If rebuilt, all the correct
                //   scale and margins are set.
                CreateGeomAndObject(true);
                // DetailLog("{0},BSPrim.setSize,size={1},scale={2},mass={3},physical={4}", LocalID, _size, _scale, _mass, IsPhysical);
            });
        } 
    }
    // Scale is what we set in the physics engine. It is different than 'size' in that
    //     'size' can be encorporated into the mesh. In that case, the scale is <1,1,1>.
    public OMV.Vector3 Scale
    {
        get { return _scale; }
        set { _scale = value; }
    }
    public override PrimitiveBaseShape Shape { 
        set {
            _pbs = value;
            PhysicsScene.TaintedObject("BSPrim.setShape", delegate()
            {
                _mass = CalculateMass();   // changing the shape changes the mass
                CreateGeomAndObject(true);
            });
        } 
    }
    public override bool Grabbed { 
        set { _grabbed = value; 
        } 
    }
    public override bool Selected { 
        set {
            _isSelected = value;
            PhysicsScene.TaintedObject("BSPrim.setSelected", delegate()
            {
                // DetailLog("{0},BSPrim.selected,taint,selected={1}", LocalID, _isSelected);
                SetObjectDynamic(false);
            });
        } 
    }
    public override void CrossingFailure() { return; }

    // link me to the specified parent
    public override void link(PhysicsActor obj) {
        BSPrim parent = obj as BSPrim;
        if (parent != null)
        {
            BSPhysObject parentBefore = Linkset.LinksetRoot;
            int childrenBefore = Linkset.NumberOfChildren;

            Linkset = parent.Linkset.AddMeToLinkset(this);

            DetailLog("{0},BSPrim.link,call,parentBefore={1}, childrenBefore=={2}, parentAfter={3}, childrenAfter={4}", 
                LocalID, parentBefore.LocalID, childrenBefore, Linkset.LinksetRoot.LocalID, Linkset.NumberOfChildren);
        }
        return; 
    }

    // delink me from my linkset
    public override void delink() {
        // TODO: decide if this parent checking needs to happen at taint time
        // Race condition here: if link() and delink() in same simulation tick, the delink will not happen

        BSPhysObject parentBefore = Linkset.LinksetRoot;
        int childrenBefore = Linkset.NumberOfChildren;
        
        Linkset = Linkset.RemoveMeFromLinkset(this);

        DetailLog("{0},BSPrim.delink,parentBefore={1},childrenBefore={2},parentAfter={3},childrenAfter={4}, ", 
            LocalID, parentBefore.LocalID, childrenBefore, Linkset.LinksetRoot.LocalID, Linkset.NumberOfChildren);
        return; 
    }

    // Set motion values to zero.
    // Do it to the properties so the values get set in the physics engine.
    // Push the setting of the values to the viewer.
    // Called at taint time!
    public override void ZeroMotion()
    {
        _velocity = OMV.Vector3.Zero;
        _acceleration = OMV.Vector3.Zero;
        _rotationalVelocity = OMV.Vector3.Zero;

        // Zero some other properties directly into the physics engine
        BulletSimAPI.SetLinearVelocity2(BSBody.ptr, OMV.Vector3.Zero);
        BulletSimAPI.SetAngularVelocity2(BSBody.ptr, OMV.Vector3.Zero);
        BulletSimAPI.SetInterpolationVelocity2(BSBody.ptr, OMV.Vector3.Zero, OMV.Vector3.Zero);
        BulletSimAPI.ClearForces2(BSBody.ptr);
    }

    public override void LockAngularMotion(OMV.Vector3 axis)
    { 
        DetailLog("{0},BSPrim.LockAngularMotion,call,axis={1}", LocalID, axis);
        return;
    }

    public override OMV.Vector3 Position { 
        get { 
            if (!Linkset.IsRoot(this))
                // child prims move around based on their parent. Need to get the latest location
                _position = BulletSimAPI.GetPosition2(BSBody.ptr);

            // don't do the GetObjectPosition for root elements because this function is called a zillion times
            // _position = BulletSimAPI.GetObjectPosition2(PhysicsScene.World.ptr, BSBody.ptr);
            return _position; 
        } 
        set {
            _position = value;
            // TODO: what does it mean to set the position of a child prim?? Rebuild the constraint?
            PhysicsScene.TaintedObject("BSPrim.setPosition", delegate()
            {
                // DetailLog("{0},BSPrim.SetPosition,taint,pos={1},orient={2}", LocalID, _position, _orientation);
                BulletSimAPI.SetTranslation2(BSBody.ptr, _position, _orientation);
            });
        } 
    }

    // Return the effective mass of the object.
    // If there are multiple items in the linkset, add them together for the root
    public override float Mass
    { 
        get
        {
            // return Linkset.LinksetMass;
            return _mass;
        }
    }

    // used when we only want this prim's mass and not the linkset thing
    public override float MassRaw { get { return _mass; }  }

    // Is this used?
    public override OMV.Vector3 CenterOfMass
    {
        get { return Linkset.CenterOfMass; }
    }

    // Is this used?
    public override OMV.Vector3 GeometricCenter
    {
        get { return Linkset.GeometricCenter; }
    }

    public override OMV.Vector3 Force { 
        get { return _force; } 
        set {
            _force = value;
            PhysicsScene.TaintedObject("BSPrim.setForce", delegate()
            {
                // DetailLog("{0},BSPrim.setForce,taint,force={1}", LocalID, _force);
                BulletSimAPI.SetObjectForce2(BSBody.ptr, _force);
            });
        } 
    }

    public override int VehicleType { 
        get {
            return (int)_vehicle.Type;   // if we are a vehicle, return that type
        } 
        set {
            Vehicle type = (Vehicle)value;
            BSPrim vehiclePrim = this;
            PhysicsScene.TaintedObject("setVehicleType", delegate()
            {
                // Done at taint time so we're sure the physics engine is not using the variables
                // Vehicle code changes the parameters for this vehicle type.
                _vehicle.ProcessTypeChange(type);
                // Tell the scene about the vehicle so it will get processing each frame.
                PhysicsScene.VehicleInSceneTypeChanged(this, type);
            });
        } 
    }
    public override void VehicleFloatParam(int param, float value) 
    {
        PhysicsScene.TaintedObject("BSPrim.VehicleFloatParam", delegate()
        {
            _vehicle.ProcessFloatVehicleParam((Vehicle)param, value);
        });
    }
    public override void VehicleVectorParam(int param, OMV.Vector3 value) 
    {
        PhysicsScene.TaintedObject("BSPrim.VehicleVectorParam", delegate()
        {
            _vehicle.ProcessVectorVehicleParam((Vehicle)param, value);
        });
    }
    public override void VehicleRotationParam(int param, OMV.Quaternion rotation) 
    {
        PhysicsScene.TaintedObject("BSPrim.VehicleRotationParam", delegate()
        {
            _vehicle.ProcessRotationVehicleParam((Vehicle)param, rotation);
        });
    }
    public override void VehicleFlags(int param, bool remove) 
    {
        PhysicsScene.TaintedObject("BSPrim.VehicleFlags", delegate()
        {
            _vehicle.ProcessVehicleFlags(param, remove);
        });
    }

    // Called each simulation step to advance vehicle characteristics.
    // Called from Scene when doing simulation step so we're in taint processing time.
    public override void StepVehicle(float timeStep)
    {
        if (IsPhysical)
            _vehicle.Step(timeStep);
    }

    // Allows the detection of collisions with inherently non-physical prims. see llVolumeDetect for more
    public override void SetVolumeDetect(int param) {
        bool newValue = (param != 0);
        if (_isVolumeDetect != newValue)
        {
            _isVolumeDetect = newValue;
            PhysicsScene.TaintedObject("BSPrim.SetVolumeDetect", delegate()
            {
                // DetailLog("{0},setVolumeDetect,taint,volDetect={1}", LocalID, _isVolumeDetect);
                SetObjectDynamic(true);
            });
        }
        return; 
    }

    public override OMV.Vector3 Velocity { 
        get { return _velocity; } 
        set {
            _velocity = value;
            PhysicsScene.TaintedObject("BSPrim.setVelocity", delegate()
            {
                // DetailLog("{0},BSPrim.SetVelocity,taint,vel={1}", LocalID, _velocity);
                BulletSimAPI.SetLinearVelocity2(BSBody.ptr, _velocity);
            });
        } 
    }
    public override OMV.Vector3 Torque { 
        get { return _torque; } 
        set { _torque = value; 
            // DetailLog("{0},BSPrim.SetTorque,call,torque={1}", LocalID, _torque);
        } 
    }
    public override float CollisionScore { 
        get { return _collisionScore; } 
        set { _collisionScore = value; 
        } 
    }
    public override OMV.Vector3 Acceleration { 
        get { return _acceleration; }
        set { _acceleration = value; }
    }
    public override OMV.Quaternion Orientation { 
        get {
            if (!Linkset.IsRoot(this))
            {
                // Children move around because tied to parent. Get a fresh value.
                _orientation = BulletSimAPI.GetOrientation2(BSBody.ptr);
            }
            return _orientation;
        } 
        set {
            _orientation = value;
            // TODO: what does it mean if a child in a linkset changes its orientation? Rebuild the constraint?
            PhysicsScene.TaintedObject("BSPrim.setOrientation", delegate()
            {
                // _position = BulletSimAPI.GetObjectPosition2(PhysicsScene.World.ptr, BSBody.ptr);
                // DetailLog("{0},BSPrim.setOrientation,taint,pos={1},orient={2}", LocalID, _position, _orientation);
                BulletSimAPI.SetTranslation2(BSBody.ptr, _position, _orientation);
            });
        } 
    }
    public override int PhysicsActorType { 
        get { return _physicsActorType; } 
        set { _physicsActorType = value; } 
    }
    public override bool IsPhysical { 
        get { return _isPhysical; } 
        set {
            if (_isPhysical != value)
            {
                _isPhysical = value;
                PhysicsScene.TaintedObject("BSPrim.setIsPhysical", delegate()
                {
                    // DetailLog("{0},setIsPhysical,taint,isPhys={1}", LocalID, _isPhysical);
                    SetObjectDynamic(true);
                });
            }
        } 
    }

    // An object is static (does not move) if selected or not physical
    private bool IsStatic
    {
        get { return _isSelected || !IsPhysical; }
    }

    // An object is solid if it's not phantom and if it's not doing VolumeDetect
    public bool IsSolid
    {
        get { return !IsPhantom && !_isVolumeDetect; }
    }

    // Make gravity work if the object is physical and not selected
    // Called at taint-time!!
    private void SetObjectDynamic(bool forceRebuild)
    {
#if CSHARP_BODY_MANAGEMENT
        // Recreate the physical object if necessary
        CreateGeomAndObject(forceRebuild);
#else
        // If it's becoming dynamic, it will need hullness
        VerifyCorrectPhysicalShape();
        UpdatePhysicalParameters();
#endif  // CSHARP_BODY_MANAGEMENT
    }

    // Convert the simulator's physical properties into settings on BulletSim objects.
    // There are four flags we're interested in:
    //     IsStatic: Object does not move, otherwise the object has mass and moves
    //     isSolid: other objects bounce off of this object
    //     isVolumeDetect: other objects pass through but can generate collisions
    //     collisionEvents: whether this object returns collision events
    private void UpdatePhysicalParameters()
    {
        // DetailLog("{0},BSPrim.UpdatePhysicalParameters,entry,body={1},shape={2}", LocalID, BSBody, BSShape);

        // Mangling all the physical properties requires the object not be in the physical world.
        // This is a NOOP if the object is not in the world (BulletSim and Bullet ignore objects not found).
        BulletSimAPI.RemoveObjectFromWorld2(PhysicsScene.World.ptr, BSBody.ptr);

#if !CSHARP_BODY_MANAGEMENT
        // Make solid or not (do things bounce off or pass through this object)
        // This is done first because it can change the collisionObject type.
        MakeSolid(IsSolid);
#endif //  !CSHARP_BODY_MANAGEMENT

        // Set up the object physicalness (does gravity and collisions move this object)
        MakeDynamic(IsStatic);

        // Arrange for collision events if the simulator wants them
        EnableCollisions(SubscribedEvents());

#if CSHARP_BODY_MANAGEMENT
        // Make solid or not (do things bounce off or pass through this object).
        MakeSolid(IsSolid);
#endif //  CSHARP_BODY_MANAGEMENT

        BulletSimAPI.AddObjectToWorld2(PhysicsScene.World.ptr, BSBody.ptr);

        // Rebuild its shape
        BulletSimAPI.UpdateSingleAabb2(PhysicsScene.World.ptr, BSBody.ptr);

        // Collision filter can be set only when the object is in the world
        if (BSBody.collisionFilter != 0 || BSBody.collisionMask != 0)
        {
            BulletSimAPI.SetCollisionFilterMask2(BSBody.ptr, (uint)BSBody.collisionFilter, (uint)BSBody.collisionMask);
        }

        // Recompute any linkset parameters.
        // When going from non-physical to physical, this re-enables the constraints that
        //     had been automatically disabled when the mass was set to zero.
        Linkset.Refresh(this);

        DetailLog("{0},BSPrim.UpdatePhysicalParameters,exit,static={1},solid={2},mass={3},collide={4},cf={5:X},body={6},shape={7}", 
                        LocalID, IsStatic, IsSolid, _mass, SubscribedEvents(), CurrentCollisionFlags, BSBody, BSShape);
    }

    // "Making dynamic" means changing to and from static.
    // When static, gravity does not effect the object and it is fixed in space.
    // When dynamic, the object can fall and be pushed by others.
    // This is independent of its 'solidness' which controls what passes through
    //    this object and what interacts with it.
    private void MakeDynamic(bool makeStatic)
    {
        if (makeStatic)
        {
            // Become a Bullet 'static' object type
            CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(BSBody.ptr, CollisionFlags.CF_STATIC_OBJECT);
            // Stop all movement
            BulletSimAPI.ClearAllForces2(BSBody.ptr);
            // Center of mass is at the center of the object
            BulletSimAPI.SetCenterOfMassByPosRot2(Linkset.LinksetRoot.BSBody.ptr, _position, _orientation);
            // Mass is zero which disables a bunch of physics stuff in Bullet
            BulletSimAPI.SetMassProps2(BSBody.ptr, 0f, OMV.Vector3.Zero);
            // There is no inertia in a static object
            BulletSimAPI.UpdateInertiaTensor2(BSBody.ptr);
            // There can be special things needed for implementing linksets
            Linkset.MakeStatic(this);
            // The activation state is 'sleeping' so Bullet will not try to act on it
            BulletSimAPI.ForceActivationState2(BSBody.ptr, ActivationState.ISLAND_SLEEPING);
            // BulletSimAPI.ForceActivationState2(BSBody.ptr, ActivationState.DISABLE_SIMULATION);

            BSBody.collisionFilter = CollisionFilterGroups.StaticObjectFilter;
            BSBody.collisionMask = CollisionFilterGroups.StaticObjectMask;
        }
        else
        {
            // Not a Bullet static object
            CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(BSBody.ptr, CollisionFlags.CF_STATIC_OBJECT);

            // Set various physical properties so internal dynamic properties will get computed correctly as they are set
            BulletSimAPI.SetFriction2(BSBody.ptr, PhysicsScene.Params.defaultFriction);
            BulletSimAPI.SetRestitution2(BSBody.ptr, PhysicsScene.Params.defaultRestitution);

            // per http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=3382
            BulletSimAPI.ClearAllForces2(BSBody.ptr);

            // A dynamic object has mass
            IntPtr collisionShapePtr = BulletSimAPI.GetCollisionShape2(BSBody.ptr);
            OMV.Vector3 inertia = BulletSimAPI.CalculateLocalInertia2(collisionShapePtr, Linkset.LinksetMass);
            BulletSimAPI.SetMassProps2(BSBody.ptr, _mass, inertia);
            BulletSimAPI.UpdateInertiaTensor2(BSBody.ptr);

            // Various values for simulation limits
            BulletSimAPI.SetDamping2(BSBody.ptr, PhysicsScene.Params.linearDamping, PhysicsScene.Params.angularDamping);
            BulletSimAPI.SetDeactivationTime2(BSBody.ptr, PhysicsScene.Params.deactivationTime);
            BulletSimAPI.SetSleepingThresholds2(BSBody.ptr, PhysicsScene.Params.linearSleepingThreshold, PhysicsScene.Params.angularSleepingThreshold);
            BulletSimAPI.SetContactProcessingThreshold2(BSBody.ptr, PhysicsScene.Params.contactProcessingThreshold);

            // There can be special things needed for implementing linksets
            Linkset.MakeDynamic(this);

            // Force activation of the object so Bullet will act on it.
            BulletSimAPI.Activate2(BSBody.ptr, true);

            BSBody.collisionFilter = CollisionFilterGroups.ObjectFilter;
            BSBody.collisionMask = CollisionFilterGroups.ObjectMask;
        }
    }

    // "Making solid" means that other object will not pass through this object.
    // To make transparent, we create a Bullet ghost object.
    // Note: This expects to be called from the UpdatePhysicalParameters() routine as
    //     the functions after this one set up the state of a possibly newly created collision body.
    private void MakeSolid(bool makeSolid)
    {
#if CSHARP_BODY_MANAGEMENT
        CollisionObjectTypes bodyType = (CollisionObjectTypes)BulletSimAPI.GetBodyType2(BSBody.ptr);
        if (makeSolid)
        {
            // Verify the previous code created the correct shape for this type of thing.
            if ((bodyType & CollisionObjectTypes.CO_RIGID_BODY) == 0)
            {
                m_log.ErrorFormat("{0} MakeSolid: physical body of wrong type for solidity. id={1}, type={2}", LogHeader, LocalID, bodyType);
            }
            CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(BSBody.ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
        }
        else
        {
            if ((bodyType & CollisionObjectTypes.CO_GHOST_OBJECT) == 0)
            {
                m_log.ErrorFormat("{0} MakeSolid: physical body of wrong type for non-solidness. id={1}, type={2}", LogHeader, LocalID, bodyType);
            }
            CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(BSBody.ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
            BSBody.collisionFilter = CollisionFilterGroups.VolumeDetectFilter;
            BSBody.collisionMask = CollisionFilterGroups.VolumeDetectMask;
        }
#else
        // If doing the body management in C#, all this logic is in CSShapeCollection.CreateObject().
        CollisionObjectTypes bodyType = (CollisionObjectTypes)BulletSimAPI.GetBodyType2(BSBody.ptr);
        if (makeSolid)
        {
            if ((bodyType & CollisionObjectTypes.CO_RIGID_BODY) == 0)
            {
                // Solid things are made out of rigid bodies. Remove this old body from the world
                //    and use this shape in a new rigid body.
                BulletBody oldBody = BSBody;
                // Zero out the pointer to the shape in the old body so the shape will not get freed
                BSShape.Ptr = BulletSimAPI.GetCollisionShape2(oldBody.Ptr);
                BulletSimAPI.SetCollisionShape2(PhysicsScene.World.Ptr, oldBody.Ptr, IntPtr.Zero);
                // Get rid of the old body and remove it from BulletSim's object list
                BulletSimAPI.DestroyObject(PhysicsScene.WorldID, LocalID);

                // Create the new body with the shape
                BSBody = new BulletBody(LocalID, BulletSimAPI.CreateBodyFromShape2(PhysicsScene.World.Ptr, BSShape.Ptr, _position, _orientation));
                CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(BSBody.Ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
                DetailLog("{0},BSPrim.MakeSolid:rigidBody,body={1},shape={2}", LocalID, BSBody, BSShape);
            }
        }
        else
        {
            if ((bodyType & CollisionObjectTypes.CO_GHOST_OBJECT) == 0)
            {
                // Non-solid things are made out of ghost objects. Remove this old body from the world
                //    and use this shape in a new rigid body.
                BulletBody oldBody = BSBody;

                // Zero out the pointer to the shape in the old body so the shape will not get freed
                BSShape.Ptr = BulletSimAPI.GetCollisionShape2(oldBody.Ptr);
                BulletSimAPI.SetCollisionShape2(PhysicsScene.World.Ptr, oldBody.Ptr, IntPtr.Zero);
                // Get rid of the old body and remove it from BulletSim's object list
                BulletSimAPI.DestroyObject(PhysicsScene.WorldID, LocalID);

                BSBody = new BulletBody(LocalID, 
                        BulletSimAPI.CreateGhostFromShape2(PhysicsScene.World.Ptr, BSShape.Ptr, _position, _orientation));
                CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(BSBody.Ptr, CollisionFlags.CF_NO_CONTACT_RESPONSE);
                DetailLog("{0},BSPrim.MakeGhostBody,body={1},shape={2}", LocalID, BSBody, BSShape);
            }
        }
#endif
    }

    // Turn on or off the flag controlling whether collision events are returned to the simulator.
    private void EnableCollisions(bool wantsCollisionEvents)
    {
        if (wantsCollisionEvents)
        {
            CurrentCollisionFlags = BulletSimAPI.AddToCollisionFlags2(BSBody.ptr, CollisionFlags.BS_SUBSCRIBE_COLLISION_EVENTS);
        }
        else
        {
            CurrentCollisionFlags = BulletSimAPI.RemoveFromCollisionFlags2(BSBody.ptr, CollisionFlags.BS_SUBSCRIBE_COLLISION_EVENTS);
        }
    }

    // prims don't fly
    public override bool Flying { 
        get { return _flying; } 
        set {
            _flying = value;
        } 
    }
    public override bool SetAlwaysRun { 
        get { return _setAlwaysRun; } 
        set { _setAlwaysRun = value; } 
    }
    public override bool ThrottleUpdates { 
        get { return _throttleUpdates; } 
        set { _throttleUpdates = value; } 
    }
    public override bool IsColliding {
        get { return (CollidingStep == PhysicsScene.SimulationStep); } 
        set { _isColliding = value; } 
    }
    public override bool CollidingGround {
        get { return (CollidingGroundStep == PhysicsScene.SimulationStep); } 
        set { _collidingGround = value; } 
    }
    public override bool CollidingObj { 
        get { return _collidingObj; } 
        set { _collidingObj = value; } 
    }
    public bool IsPhantom {
        get {
            // SceneObjectPart removes phantom objects from the physics scene
            // so, although we could implement touching and such, we never
            // are invoked as a phantom object
            return false;
        }
    }
    public override bool FloatOnWater { 
        set { _floatOnWater = value; } 
    }
    public override OMV.Vector3 RotationalVelocity { 
        get {
            /*
            OMV.Vector3 pv = OMV.Vector3.Zero;
            // if close to zero, report zero
            // This is copied from ODE but I'm not sure why it returns zero but doesn't
            //    zero the property in the physics engine.
            if (_rotationalVelocity.ApproxEquals(pv, 0.2f))
                return pv;
             */

            return _rotationalVelocity;
        } 
        set {
            _rotationalVelocity = value;
            // m_log.DebugFormat("{0}: RotationalVelocity={1}", LogHeader, _rotationalVelocity);
            PhysicsScene.TaintedObject("BSPrim.setRotationalVelocity", delegate()
            {
                // DetailLog("{0},BSPrim.SetRotationalVel,taint,rotvel={1}", LocalID, _rotationalVelocity);
                BulletSimAPI.SetAngularVelocity2(BSBody.ptr, _rotationalVelocity);
            });
        } 
    }
    public override bool Kinematic { 
        get { return _kinematic; } 
        set { _kinematic = value; 
            // m_log.DebugFormat("{0}: Kinematic={1}", LogHeader, _kinematic);
        } 
    }
    public override float Buoyancy { 
        get { return _buoyancy; } 
        set {
            _buoyancy = value;
            PhysicsScene.TaintedObject("BSPrim.setBuoyancy", delegate()
            {
                // DetailLog("{0},BSPrim.SetBuoyancy,taint,buoy={1}", LocalID, _buoyancy);
                // Buoyancy is faked by changing the gravity applied to the object
                float grav = PhysicsScene.Params.gravity * (1f - _buoyancy);
                BulletSimAPI.SetGravity2(BSBody.ptr, new OMV.Vector3(0f, 0f, grav));
            });
        } 
    }

    // Used for MoveTo
    public override OMV.Vector3 PIDTarget { 
        set { _PIDTarget = value; } 
    }
    public override bool PIDActive { 
        set { _usePID = value; } 
    }
    public override float PIDTau { 
        set { _PIDTau = value; } 
    }

    // Used for llSetHoverHeight and maybe vehicle height
    // Hover Height will override MoveTo target's Z
    public override bool PIDHoverActive { 
        set { _useHoverPID = value; }
    }
    public override float PIDHoverHeight { 
        set { _PIDHoverHeight = value; }
    }
    public override PIDHoverType PIDHoverType { 
        set { _PIDHoverType = value; }
    }
    public override float PIDHoverTau { 
        set { _PIDHoverTao = value; }
    }

    // For RotLookAt
    public override OMV.Quaternion APIDTarget { set { return; } }
    public override bool APIDActive { set { return; } }
    public override float APIDStrength { set { return; } }
    public override float APIDDamping { set { return; } }

    private List<OMV.Vector3> m_accumulatedForces = new List<OMV.Vector3>();
    public override void AddForce(OMV.Vector3 force, bool pushforce) {
        // for an object, doesn't matter if force is a pushforce or not
        if (force.IsFinite())
        {
            // _force += force;
            lock (m_accumulatedForces)
                m_accumulatedForces.Add(new OMV.Vector3(force));
        }
        else
        {
            m_log.WarnFormat("{0}: Got a NaN force applied to a prim. LocalID={1}", LogHeader, LocalID);
            return;
        }
        PhysicsScene.TaintedObject("BSPrim.AddForce", delegate()
        {
            OMV.Vector3 fSum = OMV.Vector3.Zero;
            lock (m_accumulatedForces)
            {
                foreach (OMV.Vector3 v in m_accumulatedForces)
                {
                    fSum += v;
                }
                m_accumulatedForces.Clear();
            }
            // DetailLog("{0},BSPrim.AddObjectForce,taint,force={1}", LocalID, fSum);
            // For unknown reasons, "ApplyCentralForce" adds this force to the total force on the object.
            BulletSimAPI.ApplyCentralForce2(BSBody.ptr, fSum);
        });
    }

    public override void AddAngularForce(OMV.Vector3 force, bool pushforce) { 
        // DetailLog("{0},BSPrim.AddAngularForce,call,angForce={1},push={2}", LocalID, force, pushforce);
        // m_log.DebugFormat("{0}: AddAngularForce. f={1}, push={2}", LogHeader, force, pushforce);
    }
    public override void SetMomentum(OMV.Vector3 momentum) { 
        // DetailLog("{0},BSPrim.SetMomentum,call,mom={1}", LocalID, momentum);
    }
    #region Mass Calculation

    private float CalculateMass()
    {
        float volume = _size.X * _size.Y * _size.Z; // default
        float tmp;

        float returnMass = 0;
        float hollowAmount = (float)_pbs.ProfileHollow * 2.0e-5f;
        float hollowVolume = hollowAmount * hollowAmount; 
        
        switch (_pbs.ProfileShape)
        {
            case ProfileShape.Square:
                // default box

                if (_pbs.PathCurve == (byte)Extrusion.Straight)
                    {
                    if (hollowAmount > 0.0)
                        {
                        switch (_pbs.HollowShape)
                            {
                            case HollowShape.Square:
                            case HollowShape.Same:
                                break;

                            case HollowShape.Circle:

                                hollowVolume *= 0.78539816339f;
                                break;

                            case HollowShape.Triangle:

                                hollowVolume *= (0.5f * .5f);
                                break;

                            default:
                                hollowVolume = 0;
                                break;
                            }
                        volume *= (1.0f - hollowVolume);
                        }
                    }

                else if (_pbs.PathCurve == (byte)Extrusion.Curve1)
                    {
                    //a tube 

                    volume *= 0.78539816339e-2f * (float)(200 - _pbs.PathScaleX);
                    tmp= 1.0f -2.0e-2f * (float)(200 - _pbs.PathScaleY);
                    volume -= volume*tmp*tmp;
                    
                    if (hollowAmount > 0.0)
                        {
                        hollowVolume *= hollowAmount;
                        
                        switch (_pbs.HollowShape)
                            {
                            case HollowShape.Square:
                            case HollowShape.Same:
                                break;

                            case HollowShape.Circle:
                                hollowVolume *= 0.78539816339f;;
                                break;

                            case HollowShape.Triangle:
                                hollowVolume *= 0.5f * 0.5f;
                                break;
                            default:
                                hollowVolume = 0;
                                break;
                            }
                        volume *= (1.0f - hollowVolume);
                        }
                    }

                break;

            case ProfileShape.Circle:

                if (_pbs.PathCurve == (byte)Extrusion.Straight)
                    {
                    volume *= 0.78539816339f; // elipse base

                    if (hollowAmount > 0.0)
                        {
                        switch (_pbs.HollowShape)
                            {
                            case HollowShape.Same:
                            case HollowShape.Circle:
                                break;

                            case HollowShape.Square:
                                hollowVolume *= 0.5f * 2.5984480504799f;
                                break;

                            case HollowShape.Triangle:
                                hollowVolume *= .5f * 1.27323954473516f;
                                break;

                            default:
                                hollowVolume = 0;
                                break;
                            }
                        volume *= (1.0f - hollowVolume);
                        }
                    }

                else if (_pbs.PathCurve == (byte)Extrusion.Curve1)
                    {
                    volume *= 0.61685027506808491367715568749226e-2f * (float)(200 - _pbs.PathScaleX);
                    tmp = 1.0f - .02f * (float)(200 - _pbs.PathScaleY);
                    volume *= (1.0f - tmp * tmp);
                    
                    if (hollowAmount > 0.0)
                        {

                        // calculate the hollow volume by it's shape compared to the prim shape
                        hollowVolume *= hollowAmount;

                        switch (_pbs.HollowShape)
                            {
                            case HollowShape.Same:
                            case HollowShape.Circle:
                                break;

                            case HollowShape.Square:
                                hollowVolume *= 0.5f * 2.5984480504799f;
                                break;

                            case HollowShape.Triangle:
                                hollowVolume *= .5f * 1.27323954473516f;
                                break;

                            default:
                                hollowVolume = 0;
                                break;
                            }
                        volume *= (1.0f - hollowVolume);
                        }
                    }
                break;

            case ProfileShape.HalfCircle:
                if (_pbs.PathCurve == (byte)Extrusion.Curve1)
                {
                volume *= 0.52359877559829887307710723054658f;
                }
                break;

            case ProfileShape.EquilateralTriangle:

                if (_pbs.PathCurve == (byte)Extrusion.Straight)
                    {
                    volume *= 0.32475953f;

                    if (hollowAmount > 0.0)
                        {

                        // calculate the hollow volume by it's shape compared to the prim shape
                        switch (_pbs.HollowShape)
                            {
                            case HollowShape.Same:
                            case HollowShape.Triangle:
                                hollowVolume *= .25f;
                                break;

                            case HollowShape.Square:
                                hollowVolume *= 0.499849f * 3.07920140172638f;
                                break;

                            case HollowShape.Circle:
                                // Hollow shape is a perfect cyllinder in respect to the cube's scale
                                // Cyllinder hollow volume calculation

                                hollowVolume *= 0.1963495f * 3.07920140172638f;
                                break;

                            default:
                                hollowVolume = 0;
                                break;
                            }
                        volume *= (1.0f - hollowVolume);
                        }
                    }
                else if (_pbs.PathCurve == (byte)Extrusion.Curve1)
                    {
                    volume *= 0.32475953f;
                    volume *= 0.01f * (float)(200 - _pbs.PathScaleX);
                    tmp = 1.0f - .02f * (float)(200 - _pbs.PathScaleY);
                    volume *= (1.0f - tmp * tmp);

                    if (hollowAmount > 0.0)
                        {

                        hollowVolume *= hollowAmount;

                        switch (_pbs.HollowShape)
                            {
                            case HollowShape.Same:
                            case HollowShape.Triangle:
                                hollowVolume *= .25f;
                                break;

                            case HollowShape.Square:
                                hollowVolume *= 0.499849f * 3.07920140172638f;
                                break;

                            case HollowShape.Circle:

                                hollowVolume *= 0.1963495f * 3.07920140172638f;
                                break;

                            default:
                                hollowVolume = 0;
                                break;
                            }
                        volume *= (1.0f - hollowVolume);
                        }
                    }
                    break;

            default:
                break;
            }



        float taperX1;
        float taperY1;
        float taperX;
        float taperY;
        float pathBegin;
        float pathEnd;
        float profileBegin;
        float profileEnd;

        if (_pbs.PathCurve == (byte)Extrusion.Straight || _pbs.PathCurve == (byte)Extrusion.Flexible)
            {
            taperX1 = _pbs.PathScaleX * 0.01f;
            if (taperX1 > 1.0f)
                taperX1 = 2.0f - taperX1;
            taperX = 1.0f - taperX1;

            taperY1 = _pbs.PathScaleY * 0.01f;
            if (taperY1 > 1.0f)
                taperY1 = 2.0f - taperY1;
            taperY = 1.0f - taperY1;
            }
        else
            {
            taperX = _pbs.PathTaperX * 0.01f;
            if (taperX < 0.0f)
                taperX = -taperX;
            taperX1 = 1.0f - taperX;

            taperY = _pbs.PathTaperY * 0.01f;
            if (taperY < 0.0f)
                taperY = -taperY;
            taperY1 = 1.0f - taperY;

            }


        volume *= (taperX1 * taperY1 + 0.5f * (taperX1 * taperY + taperX * taperY1) + 0.3333333333f * taperX * taperY);

        pathBegin = (float)_pbs.PathBegin * 2.0e-5f;
        pathEnd = 1.0f - (float)_pbs.PathEnd * 2.0e-5f;
        volume *= (pathEnd - pathBegin);

        // this is crude aproximation
        profileBegin = (float)_pbs.ProfileBegin * 2.0e-5f;
        profileEnd = 1.0f - (float)_pbs.ProfileEnd * 2.0e-5f;
        volume *= (profileEnd - profileBegin);

        returnMass = _density * volume;

        /*
         * This change means each object keeps its own mass and the Mass property
         * will return the sum if we're part of a linkset.
        if (IsRootOfLinkset)
        {
            foreach (BSPrim prim in _childrenPrims)
            {
                returnMass += prim.CalculateMass();
            }
        }
         */

        if (returnMass <= 0)
            returnMass = 0.0001f;

        if (returnMass > PhysicsScene.MaximumObjectMass)
            returnMass = PhysicsScene.MaximumObjectMass;

        return returnMass;
    }// end CalculateMass
    #endregion Mass Calculation

#if !CSHARP_BODY_MANAGEMENT
    // Create the geometry information in Bullet for later use.
    // The objects needs a hull if it's physical otherwise a mesh is enough.
    // No locking here because this is done when we know physics is not simulating.
    // if 'forceRebuild' is true, the geometry is rebuilt. Otherwise a previously built version is used.
    // Returns 'true' if the geometry was rebuilt.
    // Called at taint-time!
    private bool CreateGeom(bool forceRebuild)
    {
        bool ret = false;
        bool haveShape = false;

        // If the prim attributes are simple, this could be a simple Bullet native shape
        if (
            // if the basic shape is a cube or a sphere...
            ((_pbs.ProfileShape == ProfileShape.Square && _pbs.PathCurve == (byte)Extrusion.Straight)
            || (_pbs.ProfileShape == ProfileShape.HalfCircle && _pbs.PathCurve == (byte)Extrusion.Curve1
                    /* && _pbs.Scale.X == _pbs.Scale.Y && _pbs.Scale.Y == _pbs.Scale.Z */ ))
            // ... and we are not doing sculpty meshes...
            &&  (_pbs.SculptEntry && !PhysicsScene.ShouldMeshSculptedPrim)
                // ... or this is a 'simple' shape...
                || (_pbs.ProfileBegin == 0 && _pbs.ProfileEnd == 0
                    && _pbs.ProfileHollow == 0
                    && _pbs.PathTwist == 0 && _pbs.PathTwistBegin == 0
                    && _pbs.PathBegin == 0 && _pbs.PathEnd == 0
                    && _pbs.PathTaperX == 0 && _pbs.PathTaperY == 0
                    && _pbs.PathScaleX == 100 && _pbs.PathScaleY == 100
                    && _pbs.PathShearX == 0 && _pbs.PathShearY == 0) )
            // ... then this might be representable as a native Bullet collision shape
        {
            if (_pbs.ProfileShape == ProfileShape.HalfCircle && _pbs.PathCurve == (byte)Extrusion.Curve1)
            {
                haveShape = true;
                if (forceRebuild || (_shapeType != ShapeData.PhysicsShapeType.SHAPE_SPHERE))
                {
                    DetailLog("{0},BSPrim.CreateGeom,sphere (force={1}", LocalID, forceRebuild);
                    _shapeType = ShapeData.PhysicsShapeType.SHAPE_SPHERE;
                    _meshKey = (ulong)ShapeData.FixedShapeKey.KEY_SPHERE;
                    // Bullet native objects are scaled by the Bullet engine so pass the size in
                    _scale = _size;
                    // TODO: do we need to check for and destroy a mesh or hull that might have been left from before?
                    ret = true;
                }
            }
            else
            {
                // m_log.DebugFormat("{0}: CreateGeom: Defaulting to box. lid={1}, type={2}, size={3}", LogHeader, LocalID, _shapeType, _size);
                haveShape = true;
                if (forceRebuild || (_shapeType != ShapeData.PhysicsShapeType.SHAPE_BOX))
                {
                    DetailLog("{0},BSPrim.CreateGeom,box (force={1})", LocalID, forceRebuild);
                    _shapeType = ShapeData.PhysicsShapeType.SHAPE_BOX;
                    _meshKey = (ulong)ShapeData.FixedShapeKey.KEY_BOX;
                    _scale = _size;
                    // TODO: do we need to check for and destroy a mesh or hull that might have been left from before?
                    ret = true;
                }
            }
        }
        // If a simple shape isn't happening, create a mesh and possibly a hull
        if (!haveShape)
        {
            if (IsPhysical)
            {
                if (forceRebuild || _hullKey == 0)
                {
                    // physical objects require a hull for interaction.
                    // This also creates the mesh if it doesn't already exist
                    ret = CreateGeomHull();
                }
            }
            else
            {
                if (forceRebuild || _meshKey == 0)
                {
                    // Static (non-physical) objects only need a mesh for bumping into
                    ret = CreateGeomMesh();
                }
            }
        }

        return ret;
    }

    // No locking here because this is done when we know physics is not simulating
    // Returns 'true' of a mesh was actually rebuild (we could also have one of these specs).
    // Called at taint-time!
    private bool CreateGeomMesh()
    {
        // level of detail based on size and type of the object
        float lod = PhysicsScene.MeshLOD;
        if (_pbs.SculptEntry) 
            lod = PhysicsScene.SculptLOD;
        float maxAxis = Math.Max(_size.X, Math.Max(_size.Y, _size.Z));
        if (maxAxis > PhysicsScene.MeshMegaPrimThreshold) 
            lod = PhysicsScene.MeshMegaPrimLOD;

        ulong newMeshKey = (ulong)_pbs.GetMeshKey(_size, lod);
        // m_log.DebugFormat("{0}: CreateGeomMesh: lID={1}, oldKey={2}, newKey={3}", LogHeader, LocalID, _meshKey, newMeshKey);

        // if this new shape is the same as last time, don't recreate the mesh
        if (_meshKey == newMeshKey) return false;

        DetailLog("{0},BSPrim.CreateGeomMesh,create,key={1}", LocalID, newMeshKey);
        // Since we're recreating new, get rid of any previously generated shape
        if (_meshKey != 0)
        {
            // m_log.DebugFormat("{0}: CreateGeom: deleting old mesh. lID={1}, Key={2}", LogHeader, LocalID, _meshKey);
            DetailLog("{0},BSPrim.CreateGeomMesh,deleteOld,key={1}", LocalID, _meshKey);
            BulletSimAPI.DestroyMesh(PhysicsScene.WorldID, _meshKey);
            _mesh = null;
            _meshKey = 0;
        }

        _meshKey = newMeshKey;
        // always pass false for physicalness as this creates some sort of bounding box which we don't need
        _mesh = PhysicsScene.mesher.CreateMesh(PhysObjectName, _pbs, _size, lod, false);

        int[] indices = _mesh.getIndexListAsInt();
        List<OMV.Vector3> vertices = _mesh.getVertexList();

        float[] verticesAsFloats = new float[vertices.Count * 3];
        int vi = 0;
        foreach (OMV.Vector3 vv in vertices)
        {
            verticesAsFloats[vi++] = vv.X;
            verticesAsFloats[vi++] = vv.Y;
            verticesAsFloats[vi++] = vv.Z;
        }

        // m_log.DebugFormat("{0}: CreateGeomMesh: calling CreateMesh. lid={1}, key={2}, indices={3}, vertices={4}", 
        //                  LogHeader, LocalID, _meshKey, indices.Length, vertices.Count);
        BulletSimAPI.CreateMesh(PhysicsScene.WorldID, _meshKey, indices.GetLength(0), indices, 
                                                        vertices.Count, verticesAsFloats);

        _shapeType = ShapeData.PhysicsShapeType.SHAPE_MESH;
        // meshes are already scaled by the meshmerizer
        _scale = new OMV.Vector3(1f, 1f, 1f);
        return true;
    }

    // No locking here because this is done when we know physics is not simulating
    // Returns 'true' of a mesh was actually rebuild (we could also have one of these specs).
    private bool CreateGeomHull()
    {
        float lod = _pbs.SculptEntry ? PhysicsScene.SculptLOD : PhysicsScene.MeshLOD;
        ulong newHullKey = (ulong)_pbs.GetMeshKey(_size, lod);
        // m_log.DebugFormat("{0}: CreateGeomHull: lID={1}, oldKey={2}, newKey={3}", LogHeader, LocalID, _hullKey, newHullKey);

        // if the hull hasn't changed, don't rebuild it
        if (newHullKey == _hullKey) return false;

        DetailLog("{0},BSPrim.CreateGeomHull,create,oldKey={1},newKey={2}", LocalID, _hullKey, newHullKey);
        
        // Since we're recreating new, get rid of any previously generated shape
        if (_hullKey != 0)
        {
            // m_log.DebugFormat("{0}: CreateGeom: deleting old hull. Key={1}", LogHeader, _hullKey);
            DetailLog("{0},BSPrim.CreateGeomHull,deleteOldHull,key={1}", LocalID, _hullKey);
            BulletSimAPI.DestroyHull(PhysicsScene.WorldID, _hullKey);
            _hullKey = 0;
        }

        _hullKey = newHullKey;

        // Make sure the underlying mesh exists and is correct
        CreateGeomMesh();

        int[] indices = _mesh.getIndexListAsInt();
        List<OMV.Vector3> vertices = _mesh.getVertexList();

        //format conversion from IMesh format to DecompDesc format
        List<int> convIndices = new List<int>();
        List<float3> convVertices = new List<float3>();
        for (int ii = 0; ii < indices.GetLength(0); ii++)
        {
            convIndices.Add(indices[ii]);
        }
        foreach (OMV.Vector3 vv in vertices)
        {
            convVertices.Add(new float3(vv.X, vv.Y, vv.Z));
        }

        // setup and do convex hull conversion
        _hulls = new List<ConvexResult>();
        DecompDesc dcomp = new DecompDesc();
        dcomp.mIndices = convIndices;
        dcomp.mVertices = convVertices;
        ConvexBuilder convexBuilder = new ConvexBuilder(HullReturn);
        // create the hull into the _hulls variable
        convexBuilder.process(dcomp);

        // Convert the vertices and indices for passing to unmanaged.
        // The hull information is passed as a large floating point array. 
        // The format is:
        //  convHulls[0] = number of hulls
        //  convHulls[1] = number of vertices in first hull
        //  convHulls[2] = hull centroid X coordinate
        //  convHulls[3] = hull centroid Y coordinate
        //  convHulls[4] = hull centroid Z coordinate
        //  convHulls[5] = first hull vertex X
        //  convHulls[6] = first hull vertex Y
        //  convHulls[7] = first hull vertex Z
        //  convHulls[8] = second hull vertex X
        //  ...
        //  convHulls[n] = number of vertices in second hull
        //  convHulls[n+1] = second hull centroid X coordinate
        //  ...
        //
        // TODO: is is very inefficient. Someday change the convex hull generator to return
        //   data structures that do not need to be converted in order to pass to Bullet.
        //   And maybe put the values directly into pinned memory rather than marshaling.
        int hullCount = _hulls.Count;
        int totalVertices = 1;          // include one for the count of the hulls
        foreach (ConvexResult cr in _hulls)
        {
            totalVertices += 4;                         // add four for the vertex count and centroid
            totalVertices += cr.HullIndices.Count * 3;  // we pass just triangles
        }
        float[] convHulls = new float[totalVertices];

        convHulls[0] = (float)hullCount;
        int jj = 1;
        foreach (ConvexResult cr in _hulls)
        {
            // copy vertices for index access
            float3[] verts = new float3[cr.HullVertices.Count];
            int kk = 0;
            foreach (float3 ff in cr.HullVertices)
            {
                verts[kk++] = ff;
            }

            // add to the array one hull's worth of data
            convHulls[jj++] = cr.HullIndices.Count;
            convHulls[jj++] = 0f;   // centroid x,y,z
            convHulls[jj++] = 0f;
            convHulls[jj++] = 0f;
            foreach (int ind in cr.HullIndices)
            {
                convHulls[jj++] = verts[ind].x;
                convHulls[jj++] = verts[ind].y;
                convHulls[jj++] = verts[ind].z;
            }
        }

        // create the hull definition in Bullet
        // m_log.DebugFormat("{0}: CreateGeom: calling CreateHull. lid={1}, key={2}, hulls={3}", LogHeader, LocalID, _hullKey, hullCount);
        BulletSimAPI.CreateHull(PhysicsScene.WorldID, _hullKey, hullCount, convHulls);
        _shapeType = ShapeData.PhysicsShapeType.SHAPE_HULL;
        // meshes are already scaled by the meshmerizer
        _scale = new OMV.Vector3(1f, 1f, 1f);
        DetailLog("{0},BSPrim.CreateGeomHull,done", LocalID);
        return true;
    }

    // Callback from convex hull creater with a newly created hull.
    // Just add it to the collection of hulls for this shape.
    private void HullReturn(ConvexResult result)
    {
        _hulls.Add(result);
        return;
    }

    private void VerifyCorrectPhysicalShape()
    {
        if (!IsStatic)
        {
            // if not static, it will need a hull to efficiently collide with things
            if (_hullKey == 0)
            {
                CreateGeomAndObject(false);
            }

        }
    }

    // Create an object in Bullet if it has not already been created
    // No locking here because this is done when the physics engine is not simulating
    // Returns 'true' if an object was actually created.
    private bool CreateObject()
    {
        // this routine is called when objects are rebuilt. 

        // the mesh or hull must have already been created in Bullet
        ShapeData shape;
        FillShapeInfo(out shape);
        // m_log.DebugFormat("{0}: CreateObject: lID={1}, shape={2}", LogHeader, LocalID, shape.Type);
        bool ret = BulletSimAPI.CreateObject(PhysicsScene.WorldID, shape);

        return ret;
    }
#endif  // !CSHARP_BODY_MANAGEMENT

    // Copy prim's info into the BulletSim shape description structure
    public void FillShapeInfo(out ShapeData shape)
    {
        shape.ID = LocalID;
        shape.Type = _shapeType;
        shape.Position = _position;
        shape.Rotation = _orientation;
        shape.Velocity = _velocity;
        shape.Scale = _scale;
        shape.Mass = _isPhysical ? _mass : 0f;
        shape.Buoyancy = _buoyancy;
        shape.HullKey = _hullKey;
        shape.MeshKey = _meshKey;
        shape.Friction = _friction;
        shape.Restitution = _restitution;
        shape.Collidable = (!IsPhantom) ? ShapeData.numericTrue : ShapeData.numericFalse;
        shape.Static = _isPhysical ? ShapeData.numericFalse : ShapeData.numericTrue;
        shape.Solid = IsSolid ? ShapeData.numericFalse : ShapeData.numericTrue;
        shape.Size = _size;
    }
    // Rebuild the geometry and object.
    // This is called when the shape changes so we need to recreate the mesh/hull.
    // Called at taint-time!!!
    private void CreateGeomAndObject(bool forceRebuild)
    {
#if CSHARP_BODY_MANAGEMENT
        ShapeData shapeData;
        FillShapeInfo(out shapeData);

        // Create the correct physical representation for this type of object.
        // Updates BSBody and BSShape with the new information.
        PhysicsScene.Shapes.GetBodyAndShape(forceRebuild, PhysicsScene.World, this, shapeData, _pbs);
            
        // Make sure the properties are set on the new object
        UpdatePhysicalParameters();
#else
        // m_log.DebugFormat("{0}: CreateGeomAndObject. lID={1}, force={2}", LogHeader, LocalID, forceRebuild);
        // Create the geometry that will make up the object
        if (CreateGeom(forceRebuild))
        {
            // Create the object and place it into the world
            CreateObject();

            // the CreateObject() may have recreated the rigid body. Make sure we have the latest address.
            BSBody = new BulletBody(LocalID, BulletSimAPI.GetBodyHandle2(PhysicsScene.World.Ptr, LocalID));
            BSShape = new BulletShape(BulletSimAPI.GetCollisionShape2(BSBody.Ptr), _shapeType);
            BSShape.shapeKey = _meshKey;
            DetailLog("{0},BSPrim.CreateGeomAndObject,body={1},shape={2}", LocalID, BSBody, BSShape);

            // Make sure the properties are set on the new object
            UpdatePhysicalParameters();
        }


#endif // CSHARP_BODY_MANAGEMENT
        return;
    }

    // The physics engine says that properties have updated. Update same and inform
    // the world that things have changed.
    // TODO: do we really need to check for changed? Maybe just copy values and call RequestPhysicsterseUpdate()
    enum UpdatedProperties {
        Position      = 1 << 0,
        Rotation      = 1 << 1,
        Velocity      = 1 << 2,
        Acceleration  = 1 << 3,
        RotationalVel = 1 << 4
    }

    const float ROTATION_TOLERANCE = 0.01f;
    const float VELOCITY_TOLERANCE = 0.001f;
    const float POSITION_TOLERANCE = 0.05f;
    const float ACCELERATION_TOLERANCE = 0.01f;
    const float ROTATIONAL_VELOCITY_TOLERANCE = 0.01f;

    public override void UpdateProperties(EntityProperties entprop)
    {
        /*
        UpdatedProperties changed = 0;
        // assign to the local variables so the normal set action does not happen
        // if (_position != entprop.Position)
        if (!_position.ApproxEquals(entprop.Position, POSITION_TOLERANCE))
        {
            _position = entprop.Position;
            changed |= UpdatedProperties.Position;
        }
        // if (_orientation != entprop.Rotation)
        if (!_orientation.ApproxEquals(entprop.Rotation, ROTATION_TOLERANCE))
        {
            _orientation = entprop.Rotation;
            changed |= UpdatedProperties.Rotation;
        }
        // if (_velocity != entprop.Velocity)
        if (!_velocity.ApproxEquals(entprop.Velocity, VELOCITY_TOLERANCE))
        {
            _velocity = entprop.Velocity;
            changed |= UpdatedProperties.Velocity;
        }
        // if (_acceleration != entprop.Acceleration)
        if (!_acceleration.ApproxEquals(entprop.Acceleration, ACCELERATION_TOLERANCE))
        {
            _acceleration = entprop.Acceleration;
            changed |= UpdatedProperties.Acceleration;
        }
        // if (_rotationalVelocity != entprop.RotationalVelocity)
        if (!_rotationalVelocity.ApproxEquals(entprop.RotationalVelocity, ROTATIONAL_VELOCITY_TOLERANCE))
        {
            _rotationalVelocity = entprop.RotationalVelocity;
            changed |= UpdatedProperties.RotationalVel;
        }
        if (changed != 0)
        {
            // Only update the position of single objects and linkset roots
            if (this._parentPrim == null)
            {
                base.RequestPhysicsterseUpdate();
            }
        }
        */

        // Don't check for damping here -- it's done in BulletSim and SceneObjectPart.

        // Updates only for individual prims and for the root object of a linkset.
        if (Linkset.IsRoot(this))
        {
            // Assign to the local variables so the normal set action does not happen
            _position = entprop.Position;
            _orientation = entprop.Rotation;
            _velocity = entprop.Velocity;
            _acceleration = entprop.Acceleration;
            _rotationalVelocity = entprop.RotationalVelocity;

            DetailLog("{0},BSPrim.UpdateProperties,call,pos={1},orient={2},vel={3},accel={4},rotVel={5}",
                    LocalID, _position, _orientation, _velocity, _acceleration, _rotationalVelocity);

            // BulletSimAPI.DumpRigidBody2(Scene.World.Ptr, BSBody.Ptr);

            base.RequestPhysicsterseUpdate();
        }
            /*
        else
        {
            // For debugging, we can also report the movement of children
            DetailLog("{0},BSPrim.UpdateProperties,child,pos={1},orient={2},vel={3},accel={4},rotVel={5}",
                    LocalID, entprop.Position, entprop.Rotation, entprop.Velocity, 
                    entprop.Acceleration, entprop.RotationalVelocity);
        }
             */
    }
}
}