BulletSim: add parameters for setting linkset constraint factors

OpenSim/Region/Physics/BulletSPlugin/BSPrim.cs

@@ -1295,10 +1295,9 @@ public sealed class BSPrim : PhysicsActor
     // relative to each other.
     void CreateLinkset()
     {
-        DebugLog("{0}: CreateLinkset. Root prim={1}, prims={2}", LogHeader, LocalID, _childrenPrims.Count+1);
+        // DebugLog("{0}: CreateLinkset. Root prim={1}, prims={2}", LogHeader, LocalID, _childrenPrims.Count+1);
 
         // remove any constraints that might be in place
-        DebugLog("{0}: CreateLinkset: RemoveConstraints between me and any children", LogHeader, LocalID);
         UnlinkAllChildren();
 
         // create constraints between the root prim and each of the children
@@ -1324,18 +1323,8 @@ public sealed class BSPrim : PhysicsActor
 
         // create a constraint that allows no freedom of movement between the two objects
         // http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=4818
-        DebugLog("{0}: CreateLinkset: Adding a constraint between root prim {1} and child prim {2}", LogHeader, LocalID, childPrim.LocalID);
+        // DebugLog("{0}: CreateLinkset: Adding a constraint between root prim {1} and child prim {2}", LogHeader, LocalID, childPrim.LocalID);
         DetailLog("{0},LinkAChildToMe,taint,root={1},child={2}", LocalID, LocalID, childPrim.LocalID);
-        /*
-        BulletSimAPI.AddConstraint(_scene.WorldID, LocalID, childPrim.LocalID, 
-            childRelativePosition,
-            childRelativeRotation,
-            OMV.Vector3.Zero,
-            OMV.Quaternion.Identity,
-            OMV.Vector3.Zero, OMV.Vector3.Zero,
-            OMV.Vector3.Zero, OMV.Vector3.Zero);
-         */
-        // BSConstraint constrain = new BSConstraint(_scene.World, this.Body, childPrim.Body,
         BSConstraint constrain = _scene.Constraints.CreateConstraint(
                         _scene.World, this.Body, childPrim.Body,
                         childRelativePosition,
@@ -1346,8 +1335,13 @@ public sealed class BSPrim : PhysicsActor
         constrain.SetAngularLimits(OMV.Vector3.Zero, OMV.Vector3.Zero);
 
         // tweek the constraint to increase stability
-        constrain.UseFrameOffset(true);
+        constrain.UseFrameOffset(_scene.BoolNumeric(_scene.Params.linkConstraintUseFrameOffset));
-        constrain.TranslationalLimitMotor(true, 5f, 0.1f);
+        if (_scene.BoolNumeric(_scene.Params.linkConstraintEnableTransMotor))
+        {
+            constrain.TranslationalLimitMotor(true, 
+                            _scene.Params.linkConstraintTransMotorMaxVel,
+                            _scene.Params.linkConstraintTransMotorMaxForce);
+        }
     }
 
     // Remove linkage between myself and a particular child

OpenSim/Region/Physics/BulletSPlugin/BSScene.cs

@@ -1025,6 +1025,27 @@ public class BSScene : PhysicsScene, IPhysicsParameters
             (s) => { return s.m_params[0].numberOfSolverIterations; },
             (s,p,l,v) => { s.m_params[0].numberOfSolverIterations = v; } ),
 
+	    new ParameterDefn("LinkConstraintUseFrameOffset", "For linksets built with constraints, enable frame offsetFor linksets built with constraints, enable frame offset.",
+            ConfigurationParameters.numericTrue,
+            (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("DetailedStats", "Frames between outputting detailed phys stats. (0 is off)",
             0f,
             (s,cf,p,v) => { s.m_detailedStatsStep = cf.GetInt(p, (int)v); },
@@ -1039,13 +1060,13 @@ public class BSScene : PhysicsScene, IPhysicsParameters
     };
 
     // Convert a boolean to our numeric true and false values
-    protected float NumericBool(bool b)
+    public float NumericBool(bool b)
     {
         return (b ? ConfigurationParameters.numericTrue : ConfigurationParameters.numericFalse);
     }
 
     // Convert numeric true and false values to a boolean
-    protected bool BoolNumeric(float b)
+    public bool BoolNumeric(float b)
     {
         return (b == ConfigurationParameters.numericTrue ? true : false);
     }

bin/OpenSimDefaults.ini

@@ -914,6 +914,12 @@
     ShouldEnableFrictionCaching = False;
     NumberOfSolverIterations = 0;   
 
+    ; Linkset constraint parameters
+    LinkConstraintUseFrameOffset = True;
+    LinkConstraintEnableTransMotor = True;
+    LinkConstraintTransMotorMaxVel = 5.0;
+    LinkConstraintTransMotorMaxForce = 0.1;
+
 
     ; Whether to mesh sculpties
     MeshSculptedPrim = true