BulletSim: scale the force for external AddForce by the simulation

step time so it will be applied completely the next step. The internal
AddForce routine does not scale the force.

3 files changed, 19 insertions, 1 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
index 0d13096..9013414 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs
@@ -1014,7 +1014,9 @@ public sealed class BSPrim : BSPhysObject
     public override float APIDDamping { set { return; } }
 
     public override void AddForce(OMV.Vector3 force, bool pushforce) {
-        AddForce(force, pushforce, false);
+        // Since this force is being applied in only one step, make this a force per second.
+        OMV.Vector3 addForce = force / PhysicsScene.LastTimeStep;
+        AddForce(addForce, pushforce, false);
     }
     // Applying a force just adds this to the total force on the object.
     // This added force will only last the next simulation tick.
@@ -1022,8 +1024,16 @@ public sealed class BSPrim : BSPhysObject
         // for an object, doesn't matter if force is a pushforce or not
         if (force.IsFinite())
         {
+            float magnitude = force.Length();
+            if (magnitude > 20000f)
+            {
+                // Force has a limit
+                force = force / magnitude * 20000f;
+            }
+
             OMV.Vector3 addForce = force;
             DetailLog("{0},BSPrim.addForce,call,force={1}", LocalID, addForce);
+
             PhysicsScene.TaintedObject(inTaintTime, "BSPrim.AddForce", delegate()
             {
                 // Bullet adds this central force to the total force for this tick
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
index 0022e45..b67c0ed 100644
--- a/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSScene.cs
@@ -495,6 +495,10 @@ public sealed class BSScene : PhysicsScene, IPhysicsParameters
 
         InTaintTime = false; // Only used for debugging so locking is not necessary.
 
+        // The following 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
+
         // step the physical world one interval
         m_simulationStep++;
         int numSubSteps = 0;
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
index 9d07d72..78cc26c 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
+++ b/OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt
@@ -35,6 +35,8 @@ Border crossing with linked vehicle causes crash
 Vehicles (Move smoothly)
 Add vehicle collisions so IsColliding is properly reported.
         Needed for banking, limitMotorUp, movementLimiting, ...
+VehicleAddForce is not scaled by the simulation step but it is only
+        applied for one step. Should it be scaled?
 Some vehicles should not be able to turn if no speed or off ground.
 Cannot edit/move a vehicle being ridden: it jumps back to the origional position.
 Neb car jiggling left and right
@@ -92,6 +94,8 @@ Should the different PID factors have non-equal contributions for different
 Selecting and deselecting physical objects causes CPU processing time to jump
         http://www.youtube.com/watch?v=Hjg57fWg8yI&hd=1
         put thousand physical objects, select and deselect same. CPU time will be large.
+Re-implement buoyancy as a separate force on the object rather than diddling gravity.
+        Register a pre-step event to add the force.
 
 LINKSETS
 ======================================================