public static BurstCollisionMaterial CombineWith(BurstCollisionMaterial a, BurstCollisionMaterial b)
{
BurstCollisionMaterial result = new BurstCollisionMaterial();
var frictionCombineMode = (Oni.MaterialCombineMode)math.max((int)a.frictionCombine, (int)b.frictionCombine);
var stickCombineMode = (Oni.MaterialCombineMode)math.max((int)a.stickinessCombine, (int)b.stickinessCombine);
switch (frictionCombineMode)
{
case Oni.MaterialCombineMode.Average:
result.dynamicFriction = (a.dynamicFriction + b.dynamicFriction) * 0.5f;
result.staticFriction = (a.staticFriction + b.staticFriction) * 0.5f;
result.rollingFriction = (a.rollingFriction + b.rollingFriction) * 0.5f;
break;
case Oni.MaterialCombineMode.Minimum:
result.dynamicFriction = math.min(a.dynamicFriction, b.dynamicFriction);
result.staticFriction = math.min(a.staticFriction, b.staticFriction);
result.rollingFriction = math.min(a.rollingFriction, b.rollingFriction);
break;
case Oni.MaterialCombineMode.Maximum:
result.dynamicFriction = math.max(a.dynamicFriction, b.dynamicFriction);
result.staticFriction = math.max(a.staticFriction, b.staticFriction);
result.rollingFriction = math.max(a.rollingFriction, b.rollingFriction);
break;
case Oni.MaterialCombineMode.Multiply:
result.dynamicFriction = a.dynamicFriction * b.dynamicFriction;
result.staticFriction = a.staticFriction * b.staticFriction;
result.rollingFriction = a.rollingFriction * b.rollingFriction;
break;
}
switch (stickCombineMode)
{
case Oni.MaterialCombineMode.Average:
result.stickiness = (a.stickiness + b.stickiness) * 0.5f;
break;
case Oni.MaterialCombineMode.Minimum:
result.stickiness = math.min(a.stickiness, b.stickiness);
break;
case Oni.MaterialCombineMode.Maximum:
result.stickiness = math.max(a.stickiness, b.stickiness);
break;
case Oni.MaterialCombineMode.Multiply:
result.stickiness = a.stickiness * b.stickiness;
break;
}
result.stickDistance = math.max(a.stickDistance, b.stickDistance);
result.rollingContacts = a.rollingContacts | b.rollingContacts;
return(result);
}
public void Execute()
{
for (int i = 0; i < contacts.Length; ++i)
{
var contact = contacts[i];
// Get the indices of the particle and collider involved in this contact:
int indexA = contact.entityA;
int indexB = contact.entityB;
// Skip contacts involving triggers:
if (shapes[indexB].flags > 0)
{
continue;
}
// Get the rigidbody index (might be < 0, in that case there's no rigidbody present)
int rigidbodyIndex = shapes[indexB].rigidbodyIndex;
// Combine collision materials:
BurstCollisionMaterial material = CombineCollisionMaterials(indexA, indexB);
// Calculate relative velocity:
float4 relativeVelocity = GetRelativeVelocity(indexA, rigidbodyIndex, ref contact);
// Determine adhesion impulse magnitude:
float adhesionImpulse = contact.SolveAdhesion(material.stickDistance, material.stickiness, dt);
// Determine depenetration impulse magnitude:
float depenetrationImpulse = contact.SolvePenetration(relativeVelocity, solverParameters.maxDepenetration, dt);
float totalImpulse = adhesionImpulse + depenetrationImpulse;
// Apply normal impulse to both particle and rigidbody:
if (math.abs(totalImpulse) > BurstMath.epsilon)
{
deltas[indexA] += totalImpulse * -contact.normal * contact.normalInvMassA * dt;
counts[indexA]++;
if (rigidbodyIndex >= 0)
{
var rb = rigidbodies[rigidbodyIndex];
float4 worldImpulse = inertialFrame.frame.TransformVector(totalImpulse * contact.normal);
float4 worldPoint = inertialFrame.frame.TransformPoint(contact.point);
rigidbodyLinearDeltas[rigidbodyIndex] += rb.inverseMass * worldImpulse;
rigidbodyAngularDeltas[rigidbodyIndex] += math.mul(rb.inverseInertiaTensor, new float4(math.cross((worldPoint - rb.com).xyz, worldImpulse.xyz), 0));
}
}
contacts[i] = contact;
}
}
public void Execute(int workItemIndex)
{
int start, end;
batchData.GetConstraintRange(workItemIndex, out start, out end);
for (int i = start; i < end; ++i)
{
var contact = contacts[i];
int indexA = contact.entityA;
int indexB = contact.entityB;
// Combine collision materials:
BurstCollisionMaterial material = CombineCollisionMaterials(indexA, indexB);
// Calculate relative velocity:
float4 relativeVelocity = GetRelativeVelocity(indexA, indexB);
// Determine adhesion impulse magnitude:
float adhesionImpulse = contact.SolveAdhesion(material.stickDistance, material.stickiness, dt);
// Determine depenetration impulse magnitude:
float depenetrationImpulse = contact.SolvePenetration(relativeVelocity, solverParameters.maxDepenetration, dt);
float totalImpulse = depenetrationImpulse + adhesionImpulse;
// Apply normal impulse to both particles (w/ shock propagation):
if (math.abs(totalImpulse) > BurstMath.epsilon)
{
float shock = solverParameters.shockPropagation * math.dot(contact.normal, math.normalizesafe(gravity));
float4 delta = totalImpulse * dt * -contact.normal;
deltas[indexA] += delta * contact.normalInvMassA * (1 - shock);
deltas[indexB] -= delta * contact.normalInvMassB * (1 + shock);
counts[indexA]++;
counts[indexB]++;
}
// Apply position deltas immediately, if using sequential evaluation:
if (constraintParameters.evaluationOrder == Oni.ConstraintParameters.EvaluationOrder.Sequential)
{
ApplyPositionDelta(indexA, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
ApplyPositionDelta(indexB, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
}
contacts[i] = contact;
}
}
private BurstCollisionMaterial CombineCollisionMaterials(int entityA, int entityB)
{
// Combine collision materials:
int aMaterialIndex = particleMaterialIndices[entityA];
int bMaterialIndex = particleMaterialIndices[entityB];
if (aMaterialIndex >= 0 && bMaterialIndex >= 0)
{
return(BurstCollisionMaterial.CombineWith(collisionMaterials[aMaterialIndex], collisionMaterials[bMaterialIndex]));
}
else if (aMaterialIndex >= 0)
{
return(collisionMaterials[aMaterialIndex]);
}
else if (bMaterialIndex >= 0)
{
return(collisionMaterials[bMaterialIndex]);
}
return(new BurstCollisionMaterial());
}
private BurstCollisionMaterial CombineCollisionMaterials(int entityA, int entityB)
{
// Combine collision materials:
int particleMaterialIndex = particleMaterialIndices[entityA];
int colliderMaterialIndex = shapes[entityB].materialIndex;
if (colliderMaterialIndex >= 0 && particleMaterialIndex >= 0)
{
return(BurstCollisionMaterial.CombineWith(collisionMaterials[particleMaterialIndex], collisionMaterials[colliderMaterialIndex]));
}
else if (particleMaterialIndex >= 0)
{
return(collisionMaterials[particleMaterialIndex]);
}
else if (colliderMaterialIndex >= 0)
{
return(collisionMaterials[colliderMaterialIndex]);
}
return(new BurstCollisionMaterial());
}
public void Execute(int workItemIndex)
{
int start, end;
batchData.GetConstraintRange(workItemIndex, out start, out end);
for (int i = start; i < end; ++i)
{
var contact = contacts[i];
int simplexStartA = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSizeA);
int simplexStartB = simplexCounts.GetSimplexStartAndSize(contact.bodyB, out int simplexSizeB);
// Combine collision materials:
BurstCollisionMaterial material = CombineCollisionMaterials(simplices[simplexStartA], simplices[simplexStartB]);
float4 simplexPositionA = float4.zero, simplexPositionB = float4.zero;
float simplexRadiusA = 0, simplexRadiusB = 0;
for (int j = 0; j < simplexSizeA; ++j)
{
int particleIndex = simplices[simplexStartA + j];
simplexPositionA += positions[particleIndex] * contact.pointA[j];
simplexRadiusA += BurstMath.EllipsoidRadius(contact.normal, orientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
}
for (int j = 0; j < simplexSizeB; ++j)
{
int particleIndex = simplices[simplexStartB + j];
simplexPositionB += positions[particleIndex] * contact.pointB[j];
simplexRadiusB += BurstMath.EllipsoidRadius(contact.normal, orientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
}
float4 posA = simplexPositionA - contact.normal * simplexRadiusA;
float4 posB = simplexPositionB + contact.normal * simplexRadiusB;
// adhesion:
float lambda = contact.SolveAdhesion(posA, posB, material.stickDistance, material.stickiness, substepTime);
// depenetration:
lambda += contact.SolvePenetration(posA, posB, solverParameters.maxDepenetration * substepTime);
// Apply normal impulse to both particles (w/ shock propagation):
if (math.abs(lambda) > BurstMath.epsilon)
{
float shock = solverParameters.shockPropagation * math.dot(contact.normal, math.normalizesafe(gravity));
float4 delta = lambda * contact.normal;
float baryScale = BurstMath.BaryScale(contact.pointA);
for (int j = 0; j < simplexSizeA; ++j)
{
int particleIndex = simplices[simplexStartA + j];
deltas[particleIndex] += delta * invMasses[particleIndex] * contact.pointA[j] * baryScale * (1 - shock);
counts[particleIndex]++;
}
baryScale = BurstMath.BaryScale(contact.pointB);
for (int j = 0; j < simplexSizeB; ++j)
{
int particleIndex = simplices[simplexStartB + j];
deltas[particleIndex] -= delta * invMasses[particleIndex] * contact.pointB[j] * baryScale * (1 + shock);
counts[particleIndex]++;
}
}
// Apply position deltas immediately, if using sequential evaluation:
if (constraintParameters.evaluationOrder == Oni.ConstraintParameters.EvaluationOrder.Sequential)
{
for (int j = 0; j < simplexSizeA; ++j)
{
int particleIndex = simplices[simplexStartA + j];
BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
}
for (int j = 0; j < simplexSizeB; ++j)
{
int particleIndex = simplices[simplexStartB + j];
BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
}
}
contacts[i] = contact;
}
}
public void Execute()
{
for (int i = 0; i < contacts.Length; ++i)
{
var contact = contacts[i];
// Get the indices of the particle and collider involved in this contact:
int indexA = contact.entityA;
int indexB = contact.entityB;
// Skip contacts involving triggers:
if (shapes[indexB].flags > 0)
{
continue;
}
// Get the rigidbody index (might be < 0, in that case there's no rigidbody present)
int rigidbodyIndex = shapes[indexB].rigidbodyIndex;
// Combine collision materials:
BurstCollisionMaterial material = CombineCollisionMaterials(indexA, indexB);
// Calculate relative velocity:
float4 angularVelocityA = float4.zero, rA = float4.zero, rB = float4.zero;
float4 relativeVelocity = GetRelativeVelocity(indexA, rigidbodyIndex, ref contact, ref angularVelocityA, ref rA, ref rB, material.rollingContacts > 0);
// Determine impulse magnitude:
float2 impulses = contact.SolveFriction(relativeVelocity, material.staticFriction, material.dynamicFriction, dt);
if (math.abs(impulses.x) > BurstMath.epsilon || math.abs(impulses.y) > BurstMath.epsilon)
{
float4 tangentImpulse = impulses.x * contact.tangent;
float4 bitangentImpulse = impulses.y * contact.bitangent;
float4 totalImpulse = tangentImpulse + bitangentImpulse;
deltas[indexA] += (tangentImpulse * contact.tangentInvMassA + bitangentImpulse * contact.bitangentInvMassA) * dt;
counts[indexA]++;
if (rigidbodyIndex >= 0)
{
var rb = rigidbodies[rigidbodyIndex];
float4 worldImpulse = -inertialFrame.frame.TransformVector(totalImpulse);
float4 worldPoint = inertialFrame.frame.TransformPoint(contact.point);
rigidbodyLinearDeltas[rigidbodyIndex] += rb.inverseMass * worldImpulse;
rigidbodyAngularDeltas[rigidbodyIndex] += math.mul(rb.inverseInertiaTensor, new float4(math.cross((worldPoint - rb.com).xyz, worldImpulse.xyz), 0));
}
// Rolling contacts:
if (material.rollingContacts > 0)
{
// Calculate angular velocity deltas due to friction impulse:
float4x4 solverInertiaA = BurstMath.TransformInertiaTensor(invInertiaTensors[indexA], orientations[indexA]);
float4 angVelDeltaA = math.mul(solverInertiaA, new float4(math.cross(rA.xyz, totalImpulse.xyz), 0));
float4 angVelDeltaB = float4.zero;
// Final angular velocities, after adding the deltas:
angularVelocityA += angVelDeltaA;
float4 angularVelocityB = float4.zero;
// Calculate weights (inverse masses):
float invMassA = math.length(math.mul(solverInertiaA, math.normalizesafe(angularVelocityA)));
float invMassB = 0;
if (rigidbodyIndex >= 0)
{
angVelDeltaB = math.mul(-rigidbodies[rigidbodyIndex].inverseInertiaTensor, new float4(math.cross(rB.xyz, totalImpulse.xyz), 0));
angularVelocityB = rigidbodies[rigidbodyIndex].angularVelocity + angVelDeltaB;
invMassB = math.length(math.mul(rigidbodies[rigidbodyIndex].inverseInertiaTensor, math.normalizesafe(angularVelocityB)));
}
// Calculate rolling axis and angular velocity deltas:
float4 rollAxis = float4.zero;
float rollingImpulse = contact.SolveRollingFriction(angularVelocityA, angularVelocityB, material.rollingFriction, invMassA, invMassB, ref rollAxis);
angVelDeltaA += rollAxis * rollingImpulse * invMassA;
angVelDeltaB -= rollAxis * rollingImpulse * invMassB;
// Apply orientation delta to particle:
quaternion orientationDelta = BurstIntegration.AngularVelocityToSpinQuaternion(orientations[indexA], angVelDeltaA);
quaternion qA = orientationDeltas[indexA];
qA.value += orientationDelta.value * dt;
orientationDeltas[indexA] = qA;
orientationCounts[indexA]++;
// Apply angular velocity delta to rigidbody:
if (rigidbodyIndex >= 0)
{
float4 angularDelta = rigidbodyAngularDeltas[rigidbodyIndex];
angularDelta += angVelDeltaB;
rigidbodyAngularDeltas[rigidbodyIndex] = angularDelta;
}
}
}
contacts[i] = contact;
}
}
public void Execute(int workItemIndex)
{
int start, end;
batchData.GetConstraintRange(workItemIndex, out start, out end);
for (int i = start; i < end; ++i)
{
var contact = contacts[i];
int simplexStartA = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSizeA);
int simplexStartB = simplexCounts.GetSimplexStartAndSize(contact.bodyB, out int simplexSizeB);
// Combine collision materials:
BurstCollisionMaterial material = CombineCollisionMaterials(simplices[simplexStartA], simplices[simplexStartB]);
float4 prevPositionA = float4.zero;
float4 linearVelocityA = float4.zero;
float4 angularVelocityA = float4.zero;
float4 invInertiaTensorA = float4.zero;
quaternion orientationA = new quaternion(0, 0, 0, 0);
float simplexRadiusA = 0;
float4 prevPositionB = float4.zero;
float4 linearVelocityB = float4.zero;
float4 angularVelocityB = float4.zero;
float4 invInertiaTensorB = float4.zero;
quaternion orientationB = new quaternion(0, 0, 0, 0);
float simplexRadiusB = 0;
for (int j = 0; j < simplexSizeA; ++j)
{
int particleIndex = simplices[simplexStartA + j];
prevPositionA += prevPositions[particleIndex] * contact.pointA[j];
linearVelocityA += BurstIntegration.DifferentiateLinear(positions[particleIndex], prevPositions[particleIndex], substepTime) * contact.pointA[j];
angularVelocityA += BurstIntegration.DifferentiateAngular(orientations[particleIndex], prevOrientations[particleIndex], substepTime) * contact.pointA[j];
invInertiaTensorA += invInertiaTensors[particleIndex] * contact.pointA[j];
orientationA.value += orientations[particleIndex].value * contact.pointA[j];
simplexRadiusA += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
}
for (int j = 0; j < simplexSizeB; ++j)
{
int particleIndex = simplices[simplexStartB + j];
prevPositionB += prevPositions[particleIndex] * contact.pointB[j];
linearVelocityB += BurstIntegration.DifferentiateLinear(positions[particleIndex], prevPositions[particleIndex], substepTime) * contact.pointB[j];
angularVelocityB += BurstIntegration.DifferentiateAngular(orientations[particleIndex], prevOrientations[particleIndex], substepTime) * contact.pointB[j];
invInertiaTensorB += invInertiaTensors[particleIndex] * contact.pointB[j];
orientationB.value += orientations[particleIndex].value * contact.pointB[j];
simplexRadiusB += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointB[j];
}
float4 rA = float4.zero, rB = float4.zero;
// Consider angular velocities if rolling contacts are enabled:
if (material.rollingContacts > 0)
{
rA = -contact.normal * simplexRadiusA;
rB = contact.normal * simplexRadiusB;
linearVelocityA += new float4(math.cross(angularVelocityA.xyz, rA.xyz), 0);
linearVelocityB += new float4(math.cross(angularVelocityB.xyz, rB.xyz), 0);
}
// Calculate relative velocity:
float4 relativeVelocity = linearVelocityA - linearVelocityB;
// Calculate friction impulses (in the tangent and bitangent ddirections):
float2 impulses = contact.SolveFriction(relativeVelocity, material.staticFriction, material.dynamicFriction, substepTime);
// Apply friction impulses to both particles:
if (math.abs(impulses.x) > BurstMath.epsilon || math.abs(impulses.y) > BurstMath.epsilon)
{
float4 tangentImpulse = impulses.x * contact.tangent;
float4 bitangentImpulse = impulses.y * contact.bitangent;
float4 totalImpulse = tangentImpulse + bitangentImpulse;
float baryScale = BurstMath.BaryScale(contact.pointA);
for (int j = 0; j < simplexSizeA; ++j)
{
int particleIndex = simplices[simplexStartA + j];
deltas[particleIndex] += (tangentImpulse * contact.tangentInvMassA + bitangentImpulse * contact.bitangentInvMassA) * substepTime * contact.pointA[j] * baryScale;
counts[particleIndex]++;
}
baryScale = BurstMath.BaryScale(contact.pointB);
for (int j = 0; j < simplexSizeB; ++j)
{
int particleIndex = simplices[simplexStartB + j];
deltas[particleIndex] -= (tangentImpulse * contact.tangentInvMassB + bitangentImpulse * contact.bitangentInvMassB) * substepTime * contact.pointB[j] * baryScale;
counts[particleIndex]++;
}
// Rolling contacts:
if (material.rollingContacts > 0)
{
// Calculate angular velocity deltas due to friction impulse:
float4x4 solverInertiaA = BurstMath.TransformInertiaTensor(invInertiaTensorA, orientationA);
float4x4 solverInertiaB = BurstMath.TransformInertiaTensor(invInertiaTensorB, orientationB);
float4 angVelDeltaA = math.mul(solverInertiaA, new float4(math.cross(rA.xyz, totalImpulse.xyz), 0));
float4 angVelDeltaB = -math.mul(solverInertiaB, new float4(math.cross(rB.xyz, totalImpulse.xyz), 0));
// Final angular velocities, after adding the deltas:
angularVelocityA += angVelDeltaA;
angularVelocityB += angVelDeltaB;
// Calculate weights (inverse masses):
float invMassA = math.length(math.mul(solverInertiaA, math.normalizesafe(angularVelocityA)));
float invMassB = math.length(math.mul(solverInertiaB, math.normalizesafe(angularVelocityB)));
// Calculate rolling axis and angular velocity deltas:
float4 rollAxis = float4.zero;
float rollingImpulse = contact.SolveRollingFriction(angularVelocityA, angularVelocityB, material.rollingFriction, invMassA, invMassB, ref rollAxis);
angVelDeltaA += rollAxis * rollingImpulse * invMassA;
angVelDeltaB -= rollAxis * rollingImpulse * invMassB;
// Apply orientation deltas to particles:
quaternion orientationDeltaA = BurstIntegration.AngularVelocityToSpinQuaternion(orientationA, angVelDeltaA, substepTime);
quaternion orientationDeltaB = BurstIntegration.AngularVelocityToSpinQuaternion(orientationB, angVelDeltaB, substepTime);
for (int j = 0; j < simplexSizeA; ++j)
{
int particleIndex = simplices[simplexStartA + j];
quaternion qA = orientationDeltas[particleIndex];
qA.value += orientationDeltaA.value;
orientationDeltas[particleIndex] = qA;
orientationCounts[particleIndex]++;
}
for (int j = 0; j < simplexSizeB; ++j)
{
int particleIndex = simplices[simplexStartB + j];
quaternion qB = orientationDeltas[particleIndex];
qB.value += orientationDeltaB.value;
orientationDeltas[particleIndex] = qB;
orientationCounts[particleIndex]++;
}
}
}
contacts[i] = contact;
}
}
public void Execute(int workItemIndex)
{
int start, end;
batchData.GetConstraintRange(workItemIndex, out start, out end);
for (int i = start; i < end; ++i)
{
var contact = contacts[i];
int indexA = contact.entityA;
int indexB = contact.entityB;
// Combine collision materials:
BurstCollisionMaterial material = CombineCollisionMaterials(contact.entityA, contact.entityB);
// Calculate relative velocity:
float4 angularVelocityA = float4.zero, angularVelocityB = float4.zero, rA = float4.zero, rB = float4.zero;
float4 relativeVelocity = GetRelativeVelocity(indexA, indexB, ref contact, ref angularVelocityA, ref angularVelocityB, ref rA, ref rB, material.rollingContacts > 0);
// Calculate friction impulses (in the tangent and bitangent ddirections):
float2 impulses = contact.SolveFriction(relativeVelocity, material.staticFriction, material.dynamicFriction, dt);
// Apply friction impulses to both particles:
if (math.abs(impulses.x) > BurstMath.epsilon || math.abs(impulses.y) > BurstMath.epsilon)
{
float4 tangentImpulse = impulses.x * contact.tangent;
float4 bitangentImpulse = impulses.y * contact.bitangent;
float4 totalImpulse = tangentImpulse + bitangentImpulse;
deltas[indexA] += (tangentImpulse * contact.tangentInvMassA + bitangentImpulse * contact.bitangentInvMassA) * dt;
deltas[indexB] -= (tangentImpulse * contact.tangentInvMassB + bitangentImpulse * contact.bitangentInvMassB) * dt;
counts[indexA]++;
counts[indexB]++;
// Rolling contacts:
if (material.rollingContacts > 0)
{
// Calculate angular velocity deltas due to friction impulse:
float4x4 solverInertiaA = BurstMath.TransformInertiaTensor(invInertiaTensors[indexA], orientations[indexA]);
float4x4 solverInertiaB = BurstMath.TransformInertiaTensor(invInertiaTensors[indexB], orientations[indexB]);
float4 angVelDeltaA = math.mul(solverInertiaA, new float4(math.cross(rA.xyz, totalImpulse.xyz), 0));
float4 angVelDeltaB = -math.mul(solverInertiaB, new float4(math.cross(rB.xyz, totalImpulse.xyz), 0));
// Final angular velocities, after adding the deltas:
angularVelocityA += angVelDeltaA;
angularVelocityB += angVelDeltaB;
// Calculate weights (inverse masses):
float invMassA = math.length(math.mul(solverInertiaA, math.normalizesafe(angularVelocityA)));
float invMassB = math.length(math.mul(solverInertiaB, math.normalizesafe(angularVelocityB)));
// Calculate rolling axis and angular velocity deltas:
float4 rollAxis = float4.zero;
float rollingImpulse = contact.SolveRollingFriction(angularVelocityA, angularVelocityB, material.rollingFriction, invMassA, invMassB, ref rollAxis);
angVelDeltaA += rollAxis * rollingImpulse * invMassA;
angVelDeltaB -= rollAxis * rollingImpulse * invMassB;
// Apply orientation deltas to particles:
quaternion orientationDeltaA = BurstIntegration.AngularVelocityToSpinQuaternion(orientations[indexA], angVelDeltaA);
quaternion orientationDeltaB = BurstIntegration.AngularVelocityToSpinQuaternion(orientations[indexB], angVelDeltaB);
quaternion qA = orientationDeltas[indexA];
qA.value += orientationDeltaA.value * dt;
orientationDeltas[indexA] = qA;
orientationCounts[indexA]++;
quaternion qB = orientationDeltas[indexB];
qB.value += orientationDeltaB.value * dt;
orientationDeltas[indexB] = qB;
orientationCounts[indexB]++;
}
}
contacts[i] = contact;
}
}
public void Execute()
{
for (int i = 0; i < contacts.Length; ++i)
{
var contact = contacts[i];
// Get the indices of the particle and collider involved in this contact:
int simplexStart = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSize);
int colliderIndex = contact.bodyB;
// Skip contacts involving triggers:
if (shapes[colliderIndex].flags > 0)
{
continue;
}
// Get the rigidbody index (might be < 0, in that case there's no rigidbody present)
int rigidbodyIndex = shapes[colliderIndex].rigidbodyIndex;
// Combine collision materials (use material from first particle in simplex)
BurstCollisionMaterial material = CombineCollisionMaterials(simplices[simplexStart], colliderIndex);
// Calculate relative velocity:
float4 rA = float4.zero, rB = float4.zero;
float4 prevPositionA = float4.zero;
float4 linearVelocityA = float4.zero;
float4 angularVelocityA = float4.zero;
float4 invInertiaTensorA = float4.zero;
quaternion orientationA = new quaternion(0, 0, 0, 0);
float simplexRadiusA = 0;
for (int j = 0; j < simplexSize; ++j)
{
int particleIndex = simplices[simplexStart + j];
prevPositionA += prevPositions[particleIndex] * contact.pointA[j];
linearVelocityA += BurstIntegration.DifferentiateLinear(positions[particleIndex], prevPositions[particleIndex], substepTime) * contact.pointA[j];
angularVelocityA += BurstIntegration.DifferentiateAngular(orientations[particleIndex], prevOrientations[particleIndex], substepTime) * contact.pointA[j];
invInertiaTensorA += invInertiaTensors[particleIndex] * contact.pointA[j];
orientationA.value += orientations[particleIndex].value * contact.pointA[j];
simplexRadiusA += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
}
float4 relativeVelocity = linearVelocityA;
// Add particle angular velocity if rolling contacts are enabled:
if (material.rollingContacts > 0)
{
rA = -contact.normal * simplexRadiusA;
relativeVelocity += new float4(math.cross(angularVelocityA.xyz, rA.xyz), 0);
}
// Subtract rigidbody velocity:
if (rigidbodyIndex >= 0)
{
// Note: unlike rA, that is expressed in solver space, rB is expressed in world space.
rB = inertialFrame.frame.TransformPoint(contact.pointB) - rigidbodies[rigidbodyIndex].com;
relativeVelocity -= BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame);
}
// Determine impulse magnitude:
float2 impulses = contact.SolveFriction(relativeVelocity, material.staticFriction, material.dynamicFriction, stepTime);
if (math.abs(impulses.x) > BurstMath.epsilon || math.abs(impulses.y) > BurstMath.epsilon)
{
float4 tangentImpulse = impulses.x * contact.tangent;
float4 bitangentImpulse = impulses.y * contact.bitangent;
float4 totalImpulse = tangentImpulse + bitangentImpulse;
float baryScale = BurstMath.BaryScale(contact.pointA);
for (int j = 0; j < simplexSize; ++j)
{
int particleIndex = simplices[simplexStart + j];
//(tangentImpulse * contact.tangentInvMassA + bitangentImpulse * contact.bitangentInvMassA) * dt;
deltas[particleIndex] += (tangentImpulse * contact.tangentInvMassA + bitangentImpulse * contact.bitangentInvMassA) * substepTime * contact.pointA[j] * baryScale;
counts[particleIndex]++;
}
if (rigidbodyIndex >= 0)
{
BurstMath.ApplyImpulse(rigidbodyIndex, -totalImpulse, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame);
}
// Rolling contacts:
if (material.rollingContacts > 0)
{
// Calculate angular velocity deltas due to friction impulse:
float4x4 solverInertiaA = BurstMath.TransformInertiaTensor(invInertiaTensorA, orientationA);
float4 angVelDeltaA = math.mul(solverInertiaA, new float4(math.cross(rA.xyz, totalImpulse.xyz), 0));
float4 angVelDeltaB = float4.zero;
// Final angular velocities, after adding the deltas:
angularVelocityA += angVelDeltaA;
float4 angularVelocityB = float4.zero;
// Calculate weights (inverse masses):
float invMassA = math.length(math.mul(solverInertiaA, math.normalizesafe(angularVelocityA)));
float invMassB = 0;
if (rigidbodyIndex >= 0)
{
angVelDeltaB = math.mul(-rigidbodies[rigidbodyIndex].inverseInertiaTensor, new float4(math.cross(rB.xyz, totalImpulse.xyz), 0));
angularVelocityB = rigidbodies[rigidbodyIndex].angularVelocity + angVelDeltaB;
invMassB = math.length(math.mul(rigidbodies[rigidbodyIndex].inverseInertiaTensor, math.normalizesafe(angularVelocityB)));
}
// Calculate rolling axis and angular velocity deltas:
float4 rollAxis = float4.zero;
float rollingImpulse = contact.SolveRollingFriction(angularVelocityA, angularVelocityB, material.rollingFriction, invMassA, invMassB, ref rollAxis);
angVelDeltaA += rollAxis * rollingImpulse * invMassA;
angVelDeltaB -= rollAxis * rollingImpulse * invMassB;
// Apply orientation delta to particles:
quaternion orientationDelta = BurstIntegration.AngularVelocityToSpinQuaternion(orientationA, angVelDeltaA, substepTime);
for (int j = 0; j < simplexSize; ++j)
{
int particleIndex = simplices[simplexStart + j];
quaternion qA = orientationDeltas[particleIndex];
qA.value += orientationDelta.value;
orientationDeltas[particleIndex] = qA;
orientationCounts[particleIndex]++;
}
// Apply angular velocity delta to rigidbody:
if (rigidbodyIndex >= 0)
{
float4 angularDelta = rigidbodyAngularDeltas[rigidbodyIndex];
angularDelta += angVelDeltaB;
rigidbodyAngularDeltas[rigidbodyIndex] = angularDelta;
}
}
}
contacts[i] = contact;
}
}
public void Execute()
{
for (int i = 0; i < contacts.Length; ++i)
{
var contact = contacts[i];
int simplexStart = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSize);
int colliderIndex = contact.bodyB;
// Skip contacts involving triggers:
if (shapes[colliderIndex].flags > 0)
{
continue;
}
// Get the rigidbody index (might be < 0, in that case there's no rigidbody present)
int rigidbodyIndex = shapes[colliderIndex].rigidbodyIndex;
// Combine collision materials (use material from first particle in simplex)
BurstCollisionMaterial material = CombineCollisionMaterials(simplices[simplexStart], colliderIndex);
// Get relative velocity at contact point.
// As we do not consider true ellipses for collision detection, particle contact points are never off-axis.
// So particle angular velocity does not contribute to normal impulses, and we can skip it.
float4 simplexPosition = float4.zero;
float4 simplexPrevPosition = float4.zero;
float simplexRadius = 0;
for (int j = 0; j < simplexSize; ++j)
{
int particleIndex = simplices[simplexStart + j];
simplexPosition += positions[particleIndex] * contact.pointA[j];
simplexPrevPosition += prevPositions[particleIndex] * contact.pointA[j];
simplexRadius += BurstMath.EllipsoidRadius(contact.normal, orientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
}
// project position to the end of the full step:
float4 posA = math.lerp(simplexPrevPosition, simplexPosition, substeps);
posA += -contact.normal * simplexRadius;
float4 posB = contact.pointB;
if (rigidbodyIndex >= 0)
{
posB += BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame) * stepTime;
}
// adhesion:
float lambda = contact.SolveAdhesion(posA, posB, material.stickDistance, material.stickiness, stepTime);
// depenetration:
lambda += contact.SolvePenetration(posA, posB, solverParameters.maxDepenetration * stepTime);
// Apply normal impulse to both simplex and rigidbody:
if (math.abs(lambda) > BurstMath.epsilon)
{
float4 delta = lambda * contact.normal * BurstMath.BaryScale(contact.pointA) / substeps;
for (int j = 0; j < simplexSize; ++j)
{
int particleIndex = simplices[simplexStart + j];
deltas[particleIndex] += delta * invMasses[particleIndex] * contact.pointA[j];
counts[particleIndex]++;
}
// Apply position deltas immediately, if using sequential evaluation:
if (constraintParameters.evaluationOrder == Oni.ConstraintParameters.EvaluationOrder.Sequential)
{
for (int j = 0; j < simplexSize; ++j)
{
int particleIndex = simplices[simplexStart + j];
BurstConstraintsBatchImpl.ApplyPositionDelta(particleIndex, constraintParameters.SORFactor, ref positions, ref deltas, ref counts);
}
}
if (rigidbodyIndex >= 0)
{
BurstMath.ApplyImpulse(rigidbodyIndex, -lambda / stepTime * contact.normal, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame);
}
}
contacts[i] = contact;
}
}
