// Note that this relies on being called at TaintTime
private 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 inforced 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
private 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 normalized 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(
m_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 * liConstraint.member.Orientation;
OMV.Quaternion inverseChildRelativeRotation = OMV.Quaternion.Inverse(childRelativeRotation);
DetailLog("{0},BSLinksetConstraint.PhysicallyLinkAChildToRoot,taint,root={1},child={2}", rootPrim.LocalID, rootPrim.LocalID, liConstraint.member.LocalID);
constrain = new BS6DofConstraint(
PhysicsScene.World, rootPrim.Body, liConstraint.member.Body,
OMV.Vector3.Zero,
OMV.Quaternion.Inverse(rootPrim.Orientation),
OMV.Vector3.Zero,
OMV.Quaternion.Inverse(liConstraint.member.Orientation),
true,
true
);
// ==================================================================================
*/
break;
case ConstraintType.D6_SPRING_CONSTRAINT_TYPE:
constrain = new BSConstraintSpring(m_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;
}
linkInfo.SetLinkParameters(constrain);
m_physicsScene.Constraints.AddConstraint(constrain);
return constrain;
}
// Create a static constraint between the two passed objects
private 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 normalized 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(
m_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 * liConstraint.member.Orientation;
* OMV.Quaternion inverseChildRelativeRotation = OMV.Quaternion.Inverse(childRelativeRotation);
*
* DetailLog("{0},BSLinksetConstraint.PhysicallyLinkAChildToRoot,taint,root={1},child={2}", rootPrim.LocalID, rootPrim.LocalID, liConstraint.member.LocalID);
* constrain = new BS6DofConstraint(
* PhysicsScene.World, rootPrim.Body, liConstraint.member.Body,
* OMV.Vector3.Zero,
* OMV.Quaternion.Inverse(rootPrim.Orientation),
* OMV.Vector3.Zero,
* OMV.Quaternion.Inverse(liConstraint.member.Orientation),
* true,
* true
* );
* // ==================================================================================
*/
break;
case ConstraintType.D6_SPRING_CONSTRAINT_TYPE:
constrain = new BSConstraintSpring(m_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;
}
linkInfo.SetLinkParameters(constrain);
m_physicsScene.Constraints.AddConstraint(constrain);
return(constrain);
}
// Given a constraint, apply the current constraint parameters to same.
public override void SetLinkParameters(BSConstraint constrain)
{
member.PhysScene.DetailLog("{0},BSLinkInfoConstraint.SetLinkParameters,type={1}", member.LocalID, constraintType);
switch (constraintType)
{
case ConstraintType.BS_FIXED_CONSTRAINT_TYPE:
case ConstraintType.D6_CONSTRAINT_TYPE:
BSConstraint6Dof constrain6dof = constrain as BSConstraint6Dof;
if (constrain6dof != null)
{
// NOTE: D6_SPRING_CONSTRAINT_TYPE should be updated if you change any of this code.
// zero linear and angular limits makes the objects unable to move in relation to each other
constrain6dof.SetLinearLimits(linearLimitLow, linearLimitHigh);
constrain6dof.SetAngularLimits(angularLimitLow, angularLimitHigh);
// tweek the constraint to increase stability
constrain6dof.UseFrameOffset(useFrameOffset);
constrain6dof.TranslationalLimitMotor(enableTransMotor, transMotorMaxVel, transMotorMaxForce);
constrain6dof.SetCFMAndERP(cfm, erp);
if (solverIterations != 0f)
{
constrain6dof.SetSolverIterations(solverIterations);
}
}
break;
case ConstraintType.D6_SPRING_CONSTRAINT_TYPE:
BSConstraintSpring constrainSpring = constrain as BSConstraintSpring;
if (constrainSpring != null)
{
// zero linear and angular limits makes the objects unable to move in relation to each other
constrainSpring.SetLinearLimits(linearLimitLow, linearLimitHigh);
constrainSpring.SetAngularLimits(angularLimitLow, angularLimitHigh);
// tweek the constraint to increase stability
constrainSpring.UseFrameOffset(useFrameOffset);
constrainSpring.TranslationalLimitMotor(enableTransMotor, transMotorMaxVel, transMotorMaxForce);
constrainSpring.SetCFMAndERP(cfm, erp);
if (solverIterations != 0f)
{
constrainSpring.SetSolverIterations(solverIterations);
}
for (int ii = 0; ii < springAxisEnable.Length; ii++)
{
constrainSpring.SetAxisEnable(ii, springAxisEnable[ii]);
if (springDamping[ii] != BSAPITemplate.SPRING_NOT_SPECIFIED)
{
constrainSpring.SetDamping(ii, springDamping[ii]);
}
if (springStiffness[ii] != BSAPITemplate.SPRING_NOT_SPECIFIED)
{
constrainSpring.SetStiffness(ii, springStiffness[ii]);
}
}
constrainSpring.CalculateTransforms();
if (springLinearEquilibriumPoint != OMV.Vector3.Zero)
{
constrainSpring.SetEquilibriumPoint(springLinearEquilibriumPoint, springAngularEquilibriumPoint);
}
else
{
constrainSpring.SetEquilibriumPoint(BSAPITemplate.SPRING_NOT_SPECIFIED, BSAPITemplate.SPRING_NOT_SPECIFIED);
}
}
break;
default:
break;
}
}
// Note that this relies on being called at TaintTime
private 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 inforced 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();
}
}