BulletSim: angularMotorUp working again (seems a little slow as it takes longer than timescale to correct, but getting better). Disabled angularDeflection (need to resolve interactions between angular corrections). Update TODO list.

OpenSim/Region/Physics/BulletSPlugin/BSDynamics.cs

@@ -91,6 +91,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private Vector3 m_lastVertAttractor = Vector3.Zero;             // what VA was last applied to body
 
         //Deflection properties
+        private BSVMotor m_angularDeflectionMotor = new BSVMotor("AngularDeflection");
         private float m_angularDeflectionEfficiency = 0;
         private float m_angularDeflectionTimescale = 0;
         private float m_linearDeflectionEfficiency = 0;
@@ -102,6 +103,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private float m_bankingTimescale = 0;
 
         //Hover and Buoyancy properties
+        private BSVMotor m_hoverMotor = new BSVMotor("Hover");
         private float m_VhoverHeight = 0f;
         private float m_VhoverEfficiency = 0f;
         private float m_VhoverTimescale = 0f;
@@ -118,6 +120,10 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         // Timescale > cutoff  means no vert attractor.
         private float m_verticalAttractionTimescale = 510f;
 
+        // Just some recomputed constants:
+        static readonly float PIOverFour = ((float)Math.PI) / 4f;
+        static readonly float PIOverTwo = ((float)Math.PI) / 2f;
+
         public BSDynamics(BSScene myScene, BSPrim myPrim)
         {
             PhysicsScene = myScene;
@@ -563,9 +569,6 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 // Vehicles report collision events so we know when it's on the ground
                 BulletSimAPI.AddToCollisionFlags2(Prim.PhysBody.ptr, CollisionFlags.BS_VEHICLE_COLLISIONS);
 
-                // DEBUG DEBUG DEBUG: use uniform inertia to smooth movement added by Bullet
-                // Vector3 localInertia = new Vector3(1f, 1f, 1f);
-                // Vector3 localInertia = new Vector3(m_vehicleMass, m_vehicleMass, m_vehicleMass);
                 Vector3 localInertia = BulletSimAPI.CalculateLocalInertia2(Prim.PhysShape.ptr, m_vehicleMass);
                 BulletSimAPI.SetMassProps2(Prim.PhysBody.ptr, m_vehicleMass, localInertia);
                 BulletSimAPI.UpdateInertiaTensor2(Prim.PhysBody.ptr);
@@ -613,7 +616,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private Quaternion? m_knownOrientation;
         private Vector3? m_knownRotationalVelocity;
         private Vector3 m_knownRotationalForce;
-        private float? m_knownForwardSpeed;
+        private Vector3? m_knownForwardVelocity;    // vehicle relative forward speed
 
         private const int m_knownChangedPosition           = 1 << 0;
         private const int m_knownChangedVelocity           = 1 << 1;
@@ -632,7 +635,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             m_knownOrientation = null;
             m_knownRotationalVelocity = null;
             m_knownRotationalForce = Vector3.Zero;
-            m_knownForwardSpeed = null;
+            m_knownForwardVelocity = null;
             m_knownChanged = 0;
         }
         private void PushKnownChanged()
@@ -755,13 +758,21 @@ namespace OpenSim.Region.Physics.BulletSPlugin
             m_knownRotationalForce += aForce;
             m_knownChanged |= m_knownChangedRotationalForce;
         }
+        // Vehicle relative forward velocity
+        private Vector3 VehicleForwardVelocity
+        {
+            get
+            {
+                if (m_knownForwardVelocity == null)
+                    m_knownForwardVelocity = VehicleVelocity * Quaternion.Inverse(Quaternion.Normalize(VehicleOrientation));
+                return (Vector3)m_knownForwardVelocity;
+            }
+        }
         private float VehicleForwardSpeed
         {
             get
             {
-                if (m_knownForwardSpeed == null)
+                return VehicleForwardVelocity.X;
-                    m_knownForwardSpeed = (VehicleVelocity * Quaternion.Inverse(VehicleOrientation)).X;
-                return (float)m_knownForwardSpeed;
             }
         }
 
@@ -1025,7 +1036,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         //     set directly on the vehicle.
         private void MoveAngular(float pTimestep)
         {
-            // The user wants how many radians per second angular change?
+            // The user wants this many radians per second angular change?
             Vector3 angularMotorContribution = m_angularMotor.Step(pTimestep);
 
             // ==================================================================
@@ -1137,27 +1148,23 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 // Y error means needed rotation around X axis and visa versa.
                 // Since the error goes from zero to one, the asin is the corresponding angle.
                 ret.X = (float)Math.Asin(verticalError.Y);
-                ret.Y = (float)Math.Asin(verticalError.X);
+                // (Tilt forward (positive X) needs to tilt back (rotate negative) around Y axis.)
+                ret.Y = -(float)Math.Asin(verticalError.X);
 
                 // If verticalError.Z is negative, the vehicle is upside down. Add additional push.
                 if (verticalError.Z < 0f)
                 {
-                    ret.X += (float)Math.PI / 4f;
+                    ret.X += PIOverFour;
-                    ret.Y += (float)Math.PI / 4f;
+                    ret.Y += PIOverFour;
                 }
 
-                // Put the signs back on so the rotation is in the correct direction.
-                ret.X *= (float)Math.Sign(verticalError.Y);
-                // (Tilt forward (positive X) needs to tilt back (rotate negative) around Y axis.)
-                ret.Y *= -(float)Math.Sign(verticalError.X);
-
                 // 'ret' is now the necessary velocity to correct tilt in one second.
                 //     Correction happens over a number of seconds.
                 Vector3 unscaledContrib = ret;
                 ret /= m_verticalAttractionTimescale;
 
-                VDetailLog("{0},  MoveAngular,verticalAttraction,,verticalError={1},unscaled={2},eff={3},vertAttr={4}",
+                VDetailLog("{0},  MoveAngular,verticalAttraction,,verticalError={1},unscaled={2},eff={3},ts={4},vertAttr={5}",
-                                Prim.LocalID, verticalError, unscaledContrib, m_verticalAttractionEfficiency, ret);
+                                Prim.LocalID, verticalError, unscaledContrib, m_verticalAttractionEfficiency, m_verticalAttractionTimescale, ret);
             }
             return ret;
         }
@@ -1170,6 +1177,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         public Vector3 ComputeAngularDeflection()
         {
             Vector3 ret = Vector3.Zero;
+            return ret;         // DEBUG DEBUG DEBUG
+            // Disable angular deflection for the moment.
+            // Since angularMotorUp and angularDeflection are computed independently, they will calculate
+            //     approximately the same X or Y correction. When added together (when contributions are combined)
+            //     this creates an over-correction and then wabbling as the target is overshot.
+            // TODO: rethink how the different correction computations inter-relate.
 
             if (m_angularDeflectionEfficiency != 0)
             {
@@ -1181,15 +1194,24 @@ namespace OpenSim.Region.Physics.BulletSPlugin
                 Vector3 pointingDirection = Vector3.UnitX * VehicleOrientation;
                 pointingDirection.Normalize();
 
-                // The difference between what is and what should be
+                // The difference between what is and what should be.
                 Vector3 deflectionError = movingDirection - pointingDirection;
 
+                // Don't try to correct very large errors (not our job)
+                if (Math.Abs(deflectionError.X) > PIOverFour) deflectionError.X = 0f;
+                if (Math.Abs(deflectionError.Y) > PIOverFour) deflectionError.Y = 0f;
+                if (Math.Abs(deflectionError.Z) > PIOverFour) deflectionError.Z = 0f;
+
+                // ret = m_angularDeflectionCorrectionMotor(1f, deflectionError);
+
                 // Scale the correction by recovery timescale and efficiency
-                ret = (-deflectionError * VehicleForwardSpeed) * m_angularDeflectionEfficiency;
+                ret = (-deflectionError) * m_angularDeflectionEfficiency;
                 ret /= m_angularDeflectionTimescale;
 
                 VDetailLog("{0},  MoveAngular,Deflection,movingDir={1},pointingDir={2},deflectError={3},ret={4}",
                     Prim.LocalID, movingDirection, pointingDirection, deflectionError, ret);
+                VDetailLog("{0},  MoveAngular,Deflection,fwdSpd={1},defEff={2},defTS={3}",
+                    Prim.LocalID, VehicleForwardSpeed, m_angularDeflectionEfficiency, m_angularDeflectionTimescale);
             }
             return ret;
         }
@@ -1305,6 +1327,7 @@ namespace OpenSim.Region.Physics.BulletSPlugin
         private float ClampInRange(float low, float val, float high)
         {
             return Math.Max(low, Math.Min(val, high));
+            // return Utils.Clamp(val, low, high);
         }
 
         // Invoke the detailed logger and output something if it's enabled.

OpenSim/Region/Physics/BulletSPlugin/BulletSimTODO.txt

@@ -8,9 +8,10 @@ Enable vehicle border crossings (at least as poorly as ODE)
 	Vehicle recreated in new sim at small Z value (offset from root value?) (DONE)
 Calibrate turning radius (DONE)
 limitMotorUp calibration (more down?)
-study PID motors (include 'efficiency' implementation
+study PID motors (include 'efficiency' implementation (DONE)
 	Add to avatar movement
 
+
 CRASHES
 =================================================
 20121129.1411: editting/moving phys object across region boundries causes crash
@@ -25,7 +26,6 @@ CRASHES
 VEHICLES TODO LIST:
 =================================================
 Border crossing with linked vehicle causes crash
-Neb vehicle taking > 25ms of physics time!!
 Vehicles (Move smoothly)
 Add vehicle collisions so IsColliding is properly reported.
 	Needed for banking, limitMotorUp, movementLimiting, ...
@@ -34,28 +34,25 @@ Cannot edit/move a vehicle being ridden: it jumps back to the origional position
 Neb car jiggling left and right
 	Happens on terrain and any other mesh object. Flat cubes are much smoother.
 	This has been reduced but not eliminated.
-Light cycle falling over when driving
 Implement referenceFrame for all the motion routines.
 Angular motion around Z moves the vehicle in world Z and not vehicle Z in ODE.
 	Verify that angular motion specified around Z moves in the vehicle coordinates.
 Verify llGetVel() is returning a smooth and good value for vehicle movement.
 llGetVel() should return the root's velocity if requested in a child prim.
 Implement function efficiency for lineaar and angular motion.
-Should vehicle angular/linear movement friction happen after all the components
-	or does it only apply to the basic movement?
 After getting off a vehicle, the root prim is phantom (can be walked through)
     Need to force a position update for the root prim after compound shape destruction
 Linkset explosion after three "rides" on Nebadon lite vehicle (LinksetConstraint)
 For limitMotorUp, use raycast down to find if vehicle is in the air.
 Remove vehicle angular velocity zeroing in BSPrim.UpdateProperties().
 	A kludge that isn't fixing the real problem of Bullet adding extra motion.
+Incorporate inter-relationship of angular corrections. For instance, angularDeflection
+	and angularMotorUp will compute same X or Y correction. When added together
+	creates over-correction and over-shoot and wabbling.
 
 BULLETSIM TODO LIST:
 =================================================
 Revisit CollisionMargin. Builders notice the 0.04 spacing between prims.
-Avatar height off after unsitting (floats off ground)
-	Editting appearance then moving restores.
-	Must not be initializing height when recreating capsule after unsit.
 Duplicating a physical prim causes old prim to jump away
 	Dup a phys prim and the original become unselected and thus interacts w/ selected prim.
 Scenes with hundred of thousands of static objects take a lot of physics CPU time.
@@ -83,6 +80,8 @@ Add osGetPhysicsEngineName() so scripters can tell whether BulletSim or ODE
 Linkset.Position and Linkset.Orientation requre rewrite to properly return
 	child position. LinksetConstraint acts like it's at taint time!!
 Implement LockAngularMotion -- implements llSetStatus(ROTATE_AXIS_*, T/F)
+Should the different PID factors have non-equal contributions for different
+	values of Efficiency?
 
 LINKSETS
 ======================================================
@@ -100,17 +99,16 @@ Disable activity of passive linkset children.
 	Since the linkset is a compound object, the old prims are left lying
 	around and need to be phantomized so they don't collide, ...
 Speed up creation of large physical linksets
-	For instance, sitting in Neb's car (130 prims) takes several seconds to become physical
+	For instance, sitting in Neb's car (130 prims) takes several seconds to become physical.
+	REALLY bad for very large physical linksets (freezes the sim for many seconds).
 Eliminate collisions between objects in a linkset. (LinksetConstraint)
     Have UserPointer point to struct with localID and linksetID?
     Objects in original linkset still collide with each other?
 
 MORE
 ======================================================
-Find/remove avatar collision with ID=0.
 Test avatar walking up stairs. How does compare with SL.
     Radius of the capsule affects ability to climb edges.
-Tune terrain/object friction to be closer to SL.
 Debounce avatar contact so legs don't keep folding up when standing.
 Implement LSL physics controls. Like STATUS_ROTATE_X.
 Add border extensions to terrain to help region crossings and objects leaving region.
@@ -203,3 +201,16 @@ Single prim vehicles don't seem to properly vehiclize.
 Add material type linkage and input all the material property definitions.
 	Skeleton classes and table are in the sources but are not filled or used.
 	(Resolution: 
+Neb vehicle taking > 25ms of physics time!!
+	(Resolution: compound linksets were being rebuild WAY too often)
+Avatar height off after unsitting (floats off ground)
+	Editting appearance then moving restores.
+	Must not be initializing height when recreating capsule after unsit.
+	(Resolution: confusion of scale vs size for native objects removed)
+Light cycle falling over when driving (Resolution: implemented angularMotorUp)
+Should vehicle angular/linear movement friction happen after all the components
+	or does it only apply to the basic movement?
+	(Resolution: friction added before returning newly computed motor value.
+	What is expected by some vehicles (turning up friction to moderate speed))
+Tune terrain/object friction to be closer to SL.
+	(Resolution: added material type with friction and resolution)