// Note that this relies on being called at TaintTime
void AddAxisLockConstraint()
{
if (LockAxisConstraint == null)
{
// Lock that axis by creating a 6DOF constraint that has one end in the world and
// the other in the object.
// http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?p=20817
// http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?p=26380
// Remove any existing axis constraint (just to be sure)
RemoveAxisLockConstraint();
BSConstraint6Dof axisConstrainer = new BSConstraint6Dof(m_physicsScene.World, m_controllingPrim.PhysBody,
OMV.Vector3.Zero, OMV.Quaternion.Identity,
false /* useLinearReferenceFrameB */, true /* disableCollisionsBetweenLinkedBodies */);
LockAxisConstraint = axisConstrainer;
m_physicsScene.Constraints.AddConstraint(LockAxisConstraint);
// Remember the clocking being inforce so we can notice if they have changed
LockAxisLinearFlags = m_controllingPrim.LockedLinearAxis;
LockAxisAngularFlags = m_controllingPrim.LockedAngularAxis;
// The constraint is tied to the world and oriented to the prim.
if (
!axisConstrainer.SetLinearLimits(m_controllingPrim.LockedLinearAxisLow,
m_controllingPrim.LockedLinearAxisHigh))
{
m_physicsScene.DetailLog("{0},BSActorLockAxis.AddAxisLockConstraint,failedSetLinearLimits",
m_controllingPrim.LocalID);
}
if (
!axisConstrainer.SetAngularLimits(m_controllingPrim.LockedAngularAxisLow,
m_controllingPrim.LockedAngularAxisHigh))
{
m_physicsScene.DetailLog("{0},BSActorLockAxis.AddAxisLockConstraint,failedSetAngularLimits", m_controllingPrim.LocalID);
}
m_physicsScene.DetailLog(
"{0},BSActorLockAxis.AddAxisLockConstraint,create,linLow={1},linHi={2},angLow={3},angHi={4}",
m_controllingPrim.LocalID, m_controllingPrim.LockedLinearAxisLow,
m_controllingPrim.LockedLinearAxisHigh, m_controllingPrim.LockedAngularAxisLow,
m_controllingPrim.LockedAngularAxisHigh);
// Constants from one of the posts mentioned above and used in Bullet's ConstraintDemo.
axisConstrainer.TranslationalLimitMotor(true /* enable */, 5.0f, 0.1f);
axisConstrainer.RecomputeConstraintVariables(m_controllingPrim.RawMass);
RegisterForBeforeStepCallback();
}
}
// Note that this relies on being called at TaintTime
void AddAxisLockConstraint ()
{
if (LockAxisConstraint == null)
{
// Lock that axis by creating a 6DOF constraint that has one end in the world and
// the other in the object.
// http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?p=20817
// http://www.bulletphysics.org/Bullet/phpBB3/viewtopic.php?p=26380
// Remove any existing axis constraint (just to be sure)
RemoveAxisLockConstraint ();
BSConstraint6Dof axisConstrainer = new BSConstraint6Dof (m_physicsScene.World, m_controllingPrim.PhysBody,
OMV.Vector3.Zero, OMV.Quaternion.Identity,
false /* useLinearReferenceFrameB */, true /* disableCollisionsBetweenLinkedBodies */);
LockAxisConstraint = axisConstrainer;
m_physicsScene.Constraints.AddConstraint (LockAxisConstraint);
// Remember the clocking being inforce so we can notice if they have changed
LockAxisLinearFlags = m_controllingPrim.LockedLinearAxis;
LockAxisAngularFlags = m_controllingPrim.LockedAngularAxis;
// The constraint is tied to the world and oriented to the prim.
if (
!axisConstrainer.SetLinearLimits (m_controllingPrim.LockedLinearAxisLow,
m_controllingPrim.LockedLinearAxisHigh))
{
m_physicsScene.DetailLog ("{0},BSActorLockAxis.AddAxisLockConstraint,failedSetLinearLimits",
m_controllingPrim.LocalID);
}
if (
!axisConstrainer.SetAngularLimits (m_controllingPrim.LockedAngularAxisLow,
m_controllingPrim.LockedAngularAxisHigh))
{
m_physicsScene.DetailLog ("{0},BSActorLockAxis.AddAxisLockConstraint,failedSetAngularLimits", m_controllingPrim.LocalID);
}
m_physicsScene.DetailLog (
"{0},BSActorLockAxis.AddAxisLockConstraint,create,linLow={1},linHi={2},angLow={3},angHi={4}",
m_controllingPrim.LocalID, m_controllingPrim.LockedLinearAxisLow,
m_controllingPrim.LockedLinearAxisHigh, m_controllingPrim.LockedAngularAxisLow,
m_controllingPrim.LockedAngularAxisHigh);
// Constants from one of the posts mentioned above and used in Bullet's ConstraintDemo.
axisConstrainer.TranslationalLimitMotor (true /* enable */, 5.0f, 0.1f);
axisConstrainer.RecomputeConstraintVariables (m_controllingPrim.RawMass);
RegisterForBeforeStepCallback ();
}
}
// Create a static constraint between the two passed objects
BSConstraint BuildConstraint(BSPrimLinkable rootPrim, BSLinkInfo li)
{
BSLinkInfoConstraint linkInfo = li as BSLinkInfoConstraint;
if (linkInfo == null)
{
return(null);
}
// Zero motion for children so they don't interpolate
li.member.ZeroMotion(true);
BSConstraint constrain = null;
switch (linkInfo.constraintType)
{
case ConstraintType.BS_FIXED_CONSTRAINT_TYPE:
case ConstraintType.D6_CONSTRAINT_TYPE:
// Relative position normalaized to the root prim
// Essentually a vector pointing from center of rootPrim to center of li.member
OMV.Vector3 childRelativePosition = linkInfo.member.Position - rootPrim.Position;
// real world coordinate of midpoint between the two objects
OMV.Vector3 midPoint = rootPrim.Position + (childRelativePosition / 2);
DetailLog(
"{0},BSLinksetConstraint.BuildConstraint,6Dof,rBody={1},cBody={2},rLoc={3},cLoc={4},midLoc={5}",
rootPrim.LocalID, rootPrim.PhysBody, linkInfo.member.PhysBody, rootPrim.Position,
linkInfo.member.Position, midPoint);
// create a constraint that allows no freedom of movement between the two objects
// http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=4818
constrain = new BSConstraint6Dof(PhysicsScene.World, rootPrim.PhysBody, linkInfo.member.PhysBody,
midPoint, true, true);
/* NOTE: below is an attempt to build constraint with full frame computation, etc.
* Using the midpoint is easier since it lets the Bullet code manipulate the transforms
* of the objects.
* Code left for future programmers.
* // ==================================================================================
* // relative position normalized to the root prim
* OMV.Quaternion invThisOrientation = OMV.Quaternion.Inverse(rootPrim.Orientation);
* OMV.Vector3 childRelativePosition = (liConstraint.member.Position - rootPrim.Position) * invThisOrientation;
*
*
* // relative rotation of the child to the parent
* OMV.Quaternion childRelativeRotation = invThisOrientation * childPrim.Orientation;
* OMV.Quaternion inverseChildRelativeRotation = OMV.Quaternion.Inverse(childRelativeRotation);
*
* DetailLog("{0},BSLinksetConstraint.PhysicallyLinkAChildToRoot,taint,root={1},child={2}", rootPrim.LocalID, rootPrim.LocalID, childPrim.LocalID);
* BS6DofConstraint constrain = new BS6DofConstraint(
* PhysicsScene.World, rootPrim.Body, childPrim.Body,
* OMV.Vector3.Zero,
* OMV.Quaternion.Inverse(rootPrim.Orientation),
* OMV.Vector3.Zero,
* OMV.Quaternion.Inverse(childPrim.Orientation),
* true,
* true
* );
* // ==================================================================================
*/
break;
case ConstraintType.D6_SPRING_CONSTRAINT_TYPE:
constrain = new BSConstraintSpring(PhysicsScene.World, rootPrim.PhysBody, linkInfo.member.PhysBody,
linkInfo.frameInAloc, linkInfo.frameInArot, linkInfo.frameInBloc, linkInfo.frameInBrot,
linkInfo.useLinearReferenceFrameA,
true /*disableCollisionsBetweenLinkedBodies*/);
DetailLog("{0},BSLinksetConstraint.BuildConstraint,spring,root={1},rBody={2},child={3},cBody={4},rLoc={5},cLoc={6}",
rootPrim.LocalID,
rootPrim.LocalID, rootPrim.PhysBody.AddrString,
linkInfo.member.LocalID, linkInfo.member.PhysBody.AddrString,
rootPrim.Position, linkInfo.member.Position);
break;
default:
break;
}
if (constrain != null)
{
linkInfo.SetLinkParameters(constrain);
PhysicsScene.Constraints.AddConstraint(constrain);
}
return(constrain);
}
// Create a static constraint between the two passed objects
BSConstraint BuildConstraint(BSPrimLinkable rootPrim, BSLinkInfo li)
{
BSLinkInfoConstraint linkInfo = li as BSLinkInfoConstraint;
if (linkInfo == null) return null;
// Zero motion for children so they don't interpolate
li.member.ZeroMotion(true);
BSConstraint constrain = null;
switch (linkInfo.constraintType)
{
case ConstraintType.BS_FIXED_CONSTRAINT_TYPE:
case ConstraintType.D6_CONSTRAINT_TYPE:
// Relative position normalaized to the root prim
// Essentually a vector pointing from center of rootPrim to center of li.member
OMV.Vector3 childRelativePosition = linkInfo.member.Position - rootPrim.Position;
// real world coordinate of midpoint between the two objects
OMV.Vector3 midPoint = rootPrim.Position + (childRelativePosition/2);
DetailLog(
"{0},BSLinksetConstraint.BuildConstraint,6Dof,rBody={1},cBody={2},rLoc={3},cLoc={4},midLoc={5}",
rootPrim.LocalID, rootPrim.PhysBody, linkInfo.member.PhysBody, rootPrim.Position,
linkInfo.member.Position, midPoint);
// create a constraint that allows no freedom of movement between the two objects
// http://bulletphysics.org/Bullet/phpBB3/viewtopic.php?t=4818
constrain = new BSConstraint6Dof(PhysicsScene.World, rootPrim.PhysBody, linkInfo.member.PhysBody,
midPoint, true, true);
/* NOTE: below is an attempt to build constraint with full frame computation, etc.
* Using the midpoint is easier since it lets the Bullet code manipulate the transforms
* of the objects.
* Code left for future programmers.
// ==================================================================================
// relative position normalized to the root prim
OMV.Quaternion invThisOrientation = OMV.Quaternion.Inverse(rootPrim.Orientation);
OMV.Vector3 childRelativePosition = (liConstraint.member.Position - rootPrim.Position) * invThisOrientation;
// relative rotation of the child to the parent
OMV.Quaternion childRelativeRotation = invThisOrientation * childPrim.Orientation;
OMV.Quaternion inverseChildRelativeRotation = OMV.Quaternion.Inverse(childRelativeRotation);
DetailLog("{0},BSLinksetConstraint.PhysicallyLinkAChildToRoot,taint,root={1},child={2}", rootPrim.LocalID, rootPrim.LocalID, childPrim.LocalID);
BS6DofConstraint constrain = new BS6DofConstraint(
PhysicsScene.World, rootPrim.Body, childPrim.Body,
OMV.Vector3.Zero,
OMV.Quaternion.Inverse(rootPrim.Orientation),
OMV.Vector3.Zero,
OMV.Quaternion.Inverse(childPrim.Orientation),
true,
true
);
// ==================================================================================
*/
break;
case ConstraintType.D6_SPRING_CONSTRAINT_TYPE:
constrain = new BSConstraintSpring(PhysicsScene.World, rootPrim.PhysBody, linkInfo.member.PhysBody,
linkInfo.frameInAloc, linkInfo.frameInArot, linkInfo.frameInBloc, linkInfo.frameInBrot,
linkInfo.useLinearReferenceFrameA,
true /*disableCollisionsBetweenLinkedBodies*/);
DetailLog("{0},BSLinksetConstraint.BuildConstraint,spring,root={1},rBody={2},child={3},cBody={4},rLoc={5},cLoc={6}",
rootPrim.LocalID,
rootPrim.LocalID, rootPrim.PhysBody.AddrString,
linkInfo.member.LocalID, linkInfo.member.PhysBody.AddrString,
rootPrim.Position, linkInfo.member.Position);
break;
default:
break;
}
if (constrain != null) {
linkInfo.SetLinkParameters (constrain);
PhysicsScene.Constraints.AddConstraint (constrain);
}
return constrain;
}