From 03268d85c41c94e7b35802b9dea1ce08299e5426 Mon Sep 17 00:00:00 2001
From: Robert Adams
Date: Sun, 2 Jun 2013 10:04:15 -0700
Subject: BulletSim: comments and non-functional changes working toward the
center-of-gravity implementation.
---
.../Physics/BulletSPlugin/BSLinksetCompound.cs | 11 +++++----
OpenSim/Region/Physics/BulletSPlugin/BSParam.cs | 3 +++
.../Physics/BulletSPlugin/BSPrimDisplaced.cs | 26 +++++++++++++---------
.../Region/Physics/BulletSPlugin/BSPrimLinkable.cs | 19 ++++++++++++----
4 files changed, 39 insertions(+), 20 deletions(-)
(limited to 'OpenSim')
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
index 308cf13..30f6c8c 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSLinksetCompound.cs
@@ -315,7 +315,6 @@ public sealed class BSLinksetCompound : BSLinkset
// Note that this works for rebuilding just the root after a linkset is taken apart.
// Called at taint time!!
private bool UseBulletSimRootOffsetHack = false; // Attempt to have Bullet track the coords of root compound shape
- private bool disableCOM = true; // For basic linkset debugging, turn off the center-of-mass setting
private void RecomputeLinksetCompound()
{
try
@@ -331,9 +330,7 @@ public sealed class BSLinksetCompound : BSLinkset
// There is no reason to build all this physical stuff for a non-physical linkset.
if (!LinksetRoot.IsPhysicallyActive)
{
- // Clean up any old linkset shape and make sure the root shape is set to the root object.
DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,notPhysical", LinksetRoot.LocalID);
-
return; // Note the 'finally' clause at the botton which will get executed.
}
@@ -347,9 +344,9 @@ public sealed class BSLinksetCompound : BSLinkset
OMV.Quaternion invRootOrientation = OMV.Quaternion.Normalize(OMV.Quaternion.Inverse(LinksetRoot.RawOrientation));
- // 'centerDisplacement' is the value to subtract from children to give physical offset position
+ // 'centerDisplacementV' is the value to subtract from children to give physical offset position
OMV.Vector3 centerDisplacementV = (centerOfMassW - LinksetRoot.RawPosition) * invRootOrientation;
- if (UseBulletSimRootOffsetHack || disableCOM)
+ if (UseBulletSimRootOffsetHack || !BSParam.LinksetOffsetCenterOfMass)
{
centerDisplacementV = OMV.Vector3.Zero;
LinksetRoot.ClearDisplacement();
@@ -357,6 +354,8 @@ public sealed class BSLinksetCompound : BSLinkset
else
{
LinksetRoot.SetEffectiveCenterOfMassDisplacement(centerDisplacementV);
+ // The actual center-of-mass could have been set by the user.
+ centerDisplacementV = LinksetRoot.PositionDisplacement;
}
DetailLog("{0},BSLinksetCompound.RecomputeLinksetCompound,COM,rootPos={1},com={2},comDisp={3}",
LinksetRoot.LocalID, LinksetRoot.RawPosition, centerOfMassW, centerDisplacementV);
@@ -409,7 +408,7 @@ public sealed class BSLinksetCompound : BSLinkset
{
// Enable the physical position updator to return the position and rotation of the root shape.
// This enables a feature in the C++ code to return the world coordinates of the first shape in the
- // compound shape. This eleviates the need to offset the returned physical position by the
+ // compound shape. This aleviates the need to offset the returned physical position by the
// center-of-mass offset.
m_physicsScene.PE.AddToCollisionFlags(LinksetRoot.PhysBody, CollisionFlags.BS_RETURN_ROOT_COMPOUND_SHAPE);
}
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
index d17c8e7..0f84bf7 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSParam.cs
@@ -176,6 +176,7 @@ public static class BSParam
// Linkset implementation parameters
public static float LinksetImplementation { get; private set; }
+ public static bool LinksetOffsetCenterOfMass { get; private set; }
public static bool LinkConstraintUseFrameOffset { get; private set; }
public static bool LinkConstraintEnableTransMotor { get; private set; }
public static float LinkConstraintTransMotorMaxVel { get; private set; }
@@ -684,6 +685,8 @@ public static class BSParam
new ParameterDefn<float>("LinksetImplementation", "Type of linkset implementation (0=Constraint, 1=Compound, 2=Manual)",
(float)BSLinkset.LinksetImplementation.Compound ),
+ new ParameterDefn<bool>("LinksetOffsetCenterOfMass", "If 'true', compute linkset center-of-mass and offset linkset position to account for same",
+ false ),
new ParameterDefn<bool>("LinkConstraintUseFrameOffset", "For linksets built with constraints, enable frame offsetFor linksets built with constraints, enable frame offset.",
false ),
new ParameterDefn<bool>("LinkConstraintEnableTransMotor", "Whether to enable translational motor on linkset constraints",
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrimDisplaced.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrimDisplaced.cs
index f5ee671..9a05349 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrimDisplaced.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrimDisplaced.cs
@@ -44,12 +44,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
{
public class BSPrimDisplaced : BSPrim
{
- // The purpose of this module is to do any mapping between what the simulator thinks
+ // The purpose of this subclass is to do any mapping between what the simulator thinks
// the prim position and orientation is and what the physical position/orientation.
// This difference happens because Bullet assumes the center-of-mass is the <0,0,0>
- // of the prim/linkset. The simulator tracks the location of the prim/linkset by
- // the location of the root prim. So, if center-of-mass is anywhere but the origin
- // of the root prim, the physical origin is displaced from the simulator origin.
+ // of the prim/linkset. The simulator, on the other hand, tracks the location of
+ // the prim/linkset by the location of the root prim. So, if center-of-mass is anywhere
+ // but the origin of the root prim, the physical origin is displaced from the simulator origin.
//
// This routine works by capturing the Force* setting of position/orientation/... and
// adjusting the simulator values (being set) into the physical values.
@@ -61,6 +61,7 @@ public class BSPrimDisplaced : BSPrim
public virtual OMV.Vector3 PositionDisplacement { get; set; }
public virtual OMV.Quaternion OrientationDisplacement { get; set; }
+ public virtual OMV.Quaternion OrientationDisplacementOrigInv { get; set; }
public BSPrimDisplaced(uint localID, String primName, BSScene parent_scene, OMV.Vector3 pos, OMV.Vector3 size,
OMV.Quaternion rotation, PrimitiveBaseShape pbs, bool pisPhysical)
@@ -99,7 +100,8 @@ public class BSPrimDisplaced : BSPrim
// Remember the displacement from root as well as the origional rotation of the
// new center-of-mass.
PositionDisplacement = comDisp;
- OrientationDisplacement = OMV.Quaternion.Identity;
+ OrientationDisplacement = Quaternion.Normalize(RawOrientation);
+ OrientationDisplacementOrigInv = Quaternion.Inverse(OrientationDisplacement);
}
}
@@ -110,7 +112,7 @@ public class BSPrimDisplaced : BSPrim
{
if (PositionDisplacement != OMV.Vector3.Zero)
{
- OMV.Vector3 displacedPos = value - (PositionDisplacement * RawOrientation);
+ OMV.Vector3 displacedPos = value - (PositionDisplacement * (OrientationDisplacementOrigInv * RawOrientation));
DetailLog("{0},BSPrimDisplaced.ForcePosition,val={1},disp={2},newPos={3}", LocalID, value, PositionDisplacement, displacedPos);
base.ForcePosition = displacedPos;
}
@@ -126,7 +128,8 @@ public class BSPrimDisplaced : BSPrim
get { return base.ForceOrientation; }
set
{
- // TODO:
+ // Changing orientation also changes the position of the center-of-mass since
+ // the orientation passed is for a rotation around the root prim's center.
base.ForceOrientation = value;
}
}
@@ -150,10 +153,13 @@ public class BSPrimDisplaced : BSPrim
// Undo any center-of-mass displacement that might have been done.
if (PositionDisplacement != OMV.Vector3.Zero || OrientationDisplacement != OMV.Quaternion.Identity)
{
- // Correct for any rotation around the center-of-mass
- // TODO!!!
+ // The origional shape was offset from 'zero' by PositionDisplacement and rotated by OrientationDisplacement.
+ // These physical locations and rotation must be back converted to be centered around the displaced
+ // root shape.
+
+ // The root position is the reported position displaced by the rotated displacement.
+ OMV.Vector3 displacedPos = entprop.Position + (PositionDisplacement * (entprop.Rotation * OrientationDisplacementOrigInv));
- OMV.Vector3 displacedPos = entprop.Position + (PositionDisplacement * entprop.Rotation);
DetailLog("{0},BSPrimDisplaced.ForcePosition,physPos={1},disp={2},newPos={3}", LocalID, entprop.Position, PositionDisplacement, displacedPos);
entprop.Position = displacedPos;
// entprop.Rotation = something;
diff --git a/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs b/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs
index 87eed98..6d7de35 100755
--- a/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs
+++ b/OpenSim/Region/Physics/BulletSPlugin/BSPrimLinkable.cs
@@ -37,6 +37,12 @@ namespace OpenSim.Region.Physics.BulletSPlugin
{
public class BSPrimLinkable : BSPrimDisplaced
{
+ // The purpose of this subclass is to add linkset functionality to the prim. This overrides
+ // operations necessary for keeping the linkset created and, additionally, this
+ // calls the linkset implementation for its creation and management.
+
+ // This adds the overrides for link() and delink() so the prim is linkable.
+
public BSLinkset Linkset { get; set; }
// The index of this child prim.
public int LinksetChildIndex { get; set; }
@@ -69,8 +75,8 @@ public class BSPrimLinkable : BSPrimDisplaced
BSPrimLinkable parent = obj as BSPrimLinkable;
if (parent != null)
{
- BSPhysObject parentBefore = Linkset.LinksetRoot;
- int childrenBefore = Linkset.NumberOfChildren;
+ BSPhysObject parentBefore = Linkset.LinksetRoot; // DEBUG
+ int childrenBefore = Linkset.NumberOfChildren; // DEBUG
Linkset = parent.Linkset.AddMeToLinkset(this);
@@ -85,8 +91,8 @@ public class BSPrimLinkable : BSPrimDisplaced
// 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;
+ BSPhysObject parentBefore = Linkset.LinksetRoot; // DEBUG
+ int childrenBefore = Linkset.NumberOfChildren; // DEBUG
Linkset = Linkset.RemoveMeFromLinkset(this);
@@ -128,6 +134,7 @@ public class BSPrimLinkable : BSPrimDisplaced
get { return Linkset.LinksetMass; }
}
+ // Refresh the linkset structure and parameters when the prim's physical parameters are changed.
public override void UpdatePhysicalParameters()
{
base.UpdatePhysicalParameters();
@@ -139,6 +146,7 @@ public class BSPrimLinkable : BSPrimDisplaced
Linkset.Refresh(this);
}
+ // When the prim is made dynamic or static, the linkset needs to change.
protected override void MakeDynamic(bool makeStatic)
{
base.MakeDynamic(makeStatic);
@@ -155,6 +163,8 @@ public class BSPrimLinkable : BSPrimDisplaced
base.RemoveDependencies();
}
+ // Called after a simulation step for the changes in physical object properties.
+ // Do any filtering/modification needed for linksets.
public override void UpdateProperties(EntityProperties entprop)
{
if (Linkset.IsRoot(this))
@@ -176,6 +186,7 @@ public class BSPrimLinkable : BSPrimDisplaced
Linkset.UpdateProperties(UpdatedProperties.EntPropUpdates, this);
}
+ // Called after a simulation step to post a collision with this object.
public override bool Collide(uint collidingWith, BSPhysObject collidee,
OMV.Vector3 contactPoint, OMV.Vector3 contactNormal, float pentrationDepth)
{
--
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