BulletSim: complete movement of physical object action code out of the

physical object and into actors for setForce, setTorque, hover, lock
axis and avatar move.

1 files changed, 287 insertions, 0 deletions

diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSActorAvatarMove.cs b/OpenSim/Region/Physics/BulletSPlugin/BSActorAvatarMove.cs
new file mode 100755
index 0000000..634a898
--- /dev/null
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSActorAvatarMove.cs
@@ -0,0 +1,287 @@
+/*
+ * Copyright (c) Contributors, http://opensimulator.org/
+ * See CONTRIBUTORS.TXT for a full list of copyright holders.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions are met:
+ *     * Redistributions of source code must retain the above copyright
+ *       notice, this list of conditions and the following disclaimer.
+ *     * Redistributions in binary form must reproduce the above copyrightD
+ *       notice, this list of conditions and the following disclaimer in the
+ *       documentation and/or other materials provided with the distribution.
+ *     * Neither the name of the OpenSimulator Project nor the
+ *       names of its contributors may be used to endorse or promote products
+ *       derived from this software without specific prior written permission.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
+ * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
+ * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+ * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
+ * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
+ * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
+ * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
+ * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+ * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
+ * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ */
+
+using System;
+using System.Collections.Generic;
+using System.Linq;
+using System.Text;
+
+using OpenSim.Region.Physics.Manager;
+
+using OMV = OpenMetaverse;
+
+namespace OpenSim.Region.Physics.BulletSPlugin
+{
+public class BSActorAvatarMove : BSActor
+{
+    BSVMotor m_velocityMotor;
+
+    public BSActorAvatarMove(BSScene physicsScene, BSPhysObject pObj, string actorName)
+        : base(physicsScene, pObj, actorName)
+    {
+        m_velocityMotor = null;
+        m_physicsScene.DetailLog("{0},BSActorAvatarMove,constructor", m_controllingPrim.LocalID);
+    }
+
+    // BSActor.isActive
+    public override bool isActive
+    {
+        get { return Enabled && m_controllingPrim.IsPhysicallyActive; }
+    }
+
+    // Release any connections and resources used by the actor.
+    // BSActor.Dispose()
+    public override void Dispose()
+    {
+        Enabled = false;
+    }
+
+    // Called when physical parameters (properties set in Bullet) need to be re-applied.
+    // Called at taint-time.
+    // BSActor.Refresh()
+    public override void Refresh()
+    {
+        m_physicsScene.DetailLog("{0},BSActorAvatarMove,refresh", m_controllingPrim.LocalID);
+
+        // If not active any more, get rid of me (shouldn't ever happen, but just to be safe)
+        if (m_controllingPrim.RawForce == OMV.Vector3.Zero)
+        {
+            m_physicsScene.DetailLog("{0},BSActorAvatarMove,refresh,notAvatarMove,removing={1}", m_controllingPrim.LocalID, ActorName);
+            m_controllingPrim.PhysicalActors.RemoveAndRelease(ActorName);
+            return;
+        }
+
+        // If the object is physically active, add the hoverer prestep action
+        if (isActive)
+        {
+            ActivateAvatarMove();
+        }
+        else
+        {
+            DeactivateAvatarMove();
+        }
+    }
+
+    // The object's physical representation is being rebuilt so pick up any physical dependencies (constraints, ...).
+    //     Register a prestep action to restore physical requirements before the next simulation step.
+    // Called at taint-time.
+    // BSActor.RemoveBodyDependencies()
+    public override void RemoveBodyDependencies()
+    {
+        // Nothing to do for the hoverer since it is all software at pre-step action time.
+    }
+
+    public void SetVelocityAndTarget(OMV.Vector3 vel, OMV.Vector3 targ, bool inTaintTime)
+    {
+        m_physicsScene.TaintedObject(inTaintTime, "BSActorAvatarMove.setVelocityAndTarget", delegate()
+        {
+            m_velocityMotor.Reset();
+            m_velocityMotor.SetTarget(targ);
+            m_velocityMotor.SetCurrent(vel);
+            m_velocityMotor.Enabled = true;
+        });
+    }
+
+    // If a hover motor has not been created, create one and start the hovering.
+    private void ActivateAvatarMove()
+    {
+        if (m_velocityMotor == null)
+        {
+            // Infinite decay and timescale values so motor only changes current to target values.
+            m_velocityMotor = new BSVMotor("BSCharacter.Velocity", 
+                                                0.2f,                       // time scale
+                                                BSMotor.Infinite,           // decay time scale
+                                                BSMotor.InfiniteVector,     // friction timescale
+                                                1f                          // efficiency
+            );
+            // _velocityMotor.PhysicsScene = PhysicsScene; // DEBUG DEBUG so motor will output detail log messages.
+
+            m_physicsScene.BeforeStep += Mover;
+        }
+    }
+
+    private void DeactivateAvatarMove()
+    {
+        if (m_velocityMotor != null)
+        {
+            m_physicsScene.BeforeStep -= Mover;
+            m_velocityMotor = null;
+        }
+    }
+
+    // Called just before the simulation step. Update the vertical position for hoverness.
+    private void Mover(float timeStep)
+    {
+        // Don't do movement while the object is selected.
+        if (!isActive)
+            return;
+
+        // TODO: Decide if the step parameters should be changed depending on the avatar's
+        //     state (flying, colliding, ...). There is code in ODE to do this.
+
+        // COMMENTARY: when the user is making the avatar walk, except for falling, the velocity
+        //   specified for the avatar is the one that should be used. For falling, if the avatar
+        //   is not flying and is not colliding then it is presumed to be falling and the Z
+        //   component is not fooled with (thus allowing gravity to do its thing).
+        // When the avatar is standing, though, the user has specified a velocity of zero and
+        //   the avatar should be standing. But if the avatar is pushed by something in the world
+        //   (raising elevator platform, moving vehicle, ...) the avatar should be allowed to
+        //   move. Thus, the velocity cannot be forced to zero. The problem is that small velocity
+        //   errors can creap in and the avatar will slowly float off in some direction.
+        // So, the problem is that, when an avatar is standing, we cannot tell creaping error
+        //   from real pushing.
+        // The code below uses whether the collider is static or moving to decide whether to zero motion.
+
+        m_velocityMotor.Step(timeStep);
+        m_controllingPrim.IsStationary = false;
+
+        // If we're not supposed to be moving, make sure things are zero.
+        if (m_velocityMotor.ErrorIsZero() && m_velocityMotor.TargetValue == OMV.Vector3.Zero)
+        {
+            // The avatar shouldn't be moving
+            m_velocityMotor.Zero();
+
+            if (m_controllingPrim.IsColliding)
+            {
+                // If we are colliding with a stationary object, presume we're standing and don't move around
+                if (!m_controllingPrim.ColliderIsMoving)
+                {
+                    m_physicsScene.DetailLog("{0},BSCharacter.MoveMotor,collidingWithStationary,zeroingMotion", m_controllingPrim.LocalID);
+                    m_controllingPrim.IsStationary = true;
+                    m_controllingPrim.ZeroMotion(true /* inTaintTime */);
+                }
+
+                // Standing has more friction on the ground
+                if (m_controllingPrim.Friction != BSParam.AvatarStandingFriction)
+                {
+                    m_controllingPrim.Friction = BSParam.AvatarStandingFriction;
+                    m_physicsScene.PE.SetFriction(m_controllingPrim.PhysBody, m_controllingPrim.Friction);
+                }
+            }
+            else
+            {
+                if (m_controllingPrim.Flying)
+                {
+                    // Flying and not collising and velocity nearly zero.
+                    m_controllingPrim.ZeroMotion(true /* inTaintTime */);
+                }
+            }
+
+            m_physicsScene.DetailLog("{0},BSCharacter.MoveMotor,taint,stopping,target={1},colliding={2}",
+                            m_controllingPrim.LocalID, m_velocityMotor.TargetValue, m_controllingPrim.IsColliding);
+        }
+        else
+        {
+            // Supposed to be moving.
+            OMV.Vector3 stepVelocity = m_velocityMotor.CurrentValue;
+
+            if (m_controllingPrim.Friction != BSParam.AvatarFriction)
+            {
+                // Probably starting up walking. Set friction to moving friction.
+                m_controllingPrim.Friction = BSParam.AvatarFriction;
+                m_physicsScene.PE.SetFriction(m_controllingPrim.PhysBody, m_controllingPrim.Friction);
+            }
+
+            // If falling, we keep the world's downward vector no matter what the other axis specify.
+            // The check for RawVelocity.Z < 0 makes jumping work (temporary upward force).
+            if (!m_controllingPrim.Flying && !m_controllingPrim.IsColliding)
+            {
+                if (m_controllingPrim.RawVelocity.Z < 0)
+                    stepVelocity.Z = m_controllingPrim.RawVelocity.Z;
+                // DetailLog("{0},BSCharacter.MoveMotor,taint,overrideStepZWithWorldZ,stepVel={1}", LocalID, stepVelocity);
+            }
+
+            // 'stepVelocity' is now the speed we'd like the avatar to move in. Turn that into an instantanous force.
+            OMV.Vector3 moveForce = (stepVelocity - m_controllingPrim.RawVelocity) * m_controllingPrim.Mass;
+
+            // Should we check for move force being small and forcing velocity to zero?
+
+            // Add special movement force to allow avatars to walk up stepped surfaces.
+            moveForce += WalkUpStairs();
+
+            m_physicsScene.DetailLog("{0},BSCharacter.MoveMotor,move,stepVel={1},vel={2},mass={3},moveForce={4}",
+                            m_controllingPrim.LocalID, stepVelocity, m_controllingPrim.RawVelocity, m_controllingPrim.Mass, moveForce);
+            m_physicsScene.PE.ApplyCentralImpulse(m_controllingPrim.PhysBody, moveForce);
+        }
+    }
+
+    // Decide if the character is colliding with a low object and compute a force to pop the
+    //    avatar up so it can walk up and over the low objects.
+    private OMV.Vector3 WalkUpStairs()
+    {
+        OMV.Vector3 ret = OMV.Vector3.Zero;
+
+        // This test is done if moving forward, not flying and is colliding with something.
+        // DetailLog("{0},BSCharacter.WalkUpStairs,IsColliding={1},flying={2},targSpeed={3},collisions={4}",
+        //                 LocalID, IsColliding, Flying, TargetSpeed, CollisionsLastTick.Count);
+        if (m_controllingPrim.IsColliding && !m_controllingPrim.Flying && m_controllingPrim.TargetVelocitySpeed > 0.1f /* && ForwardSpeed < 0.1f */)
+        {
+            // The range near the character's feet where we will consider stairs
+            float nearFeetHeightMin = m_controllingPrim.RawPosition.Z - (m_controllingPrim.Size.Z / 2f) + 0.05f;
+            float nearFeetHeightMax = nearFeetHeightMin + BSParam.AvatarStepHeight;
+
+            // Look for a collision point that is near the character's feet and is oriented the same as the charactor is
+            foreach (KeyValuePair<uint, ContactPoint> kvp in m_controllingPrim.CollisionsLastTick.m_objCollisionList)
+            {
+                // Don't care about collisions with the terrain
+                if (kvp.Key > m_physicsScene.TerrainManager.HighestTerrainID)
+                {
+                    OMV.Vector3 touchPosition = kvp.Value.Position;
+                    // DetailLog("{0},BSCharacter.WalkUpStairs,min={1},max={2},touch={3}",
+                    //                 LocalID, nearFeetHeightMin, nearFeetHeightMax, touchPosition);
+                    if (touchPosition.Z >= nearFeetHeightMin && touchPosition.Z <= nearFeetHeightMax)
+                    {
+                        // This contact is within the 'near the feet' range.
+                        // The normal should be our contact point to the object so it is pointing away
+                        //    thus the difference between our facing orientation and the normal should be small.
+                        OMV.Vector3 directionFacing = OMV.Vector3.UnitX * m_controllingPrim.RawOrientation;
+                        OMV.Vector3 touchNormal = OMV.Vector3.Normalize(kvp.Value.SurfaceNormal);
+                        float diff = Math.Abs(OMV.Vector3.Distance(directionFacing, touchNormal));
+                        if (diff < BSParam.AvatarStepApproachFactor)
+                        {
+                            // Found the stairs contact point. Push up a little to raise the character.
+                            float upForce = (touchPosition.Z - nearFeetHeightMin) * m_controllingPrim.Mass * BSParam.AvatarStepForceFactor;
+                            ret = new OMV.Vector3(0f, 0f, upForce);
+
+                            // Also move the avatar up for the new height
+                            OMV.Vector3 displacement = new OMV.Vector3(0f, 0f, BSParam.AvatarStepHeight / 2f);
+                            m_controllingPrim.ForcePosition = m_controllingPrim.RawPosition + displacement;
+                        }
+                        m_physicsScene.DetailLog("{0},BSCharacter.WalkUpStairs,touchPos={1},nearFeetMin={2},faceDir={3},norm={4},diff={5},ret={6}",
+                                m_controllingPrim.LocalID, touchPosition, nearFeetHeightMin, directionFacing, touchNormal, diff, ret);
+                    }
+                }
+            }
+        }
+
+        return ret;
+    }
+
+}
+}
+
+