public static void Contacts(int particleIndex,
float4 position,
quaternion orientation,
float4 radii,
int colliderIndex,
BurstAffineTransform transform,
BurstColliderShape shape,
NativeQueue <BurstContact> .ParallelWriter contacts)
{
float4 center = shape.center * transform.scale;
position = transform.InverseTransformPointUnscaled(position) - center;
float radius = shape.size.x * math.cmax(transform.scale.xyz);
float distanceToCenter = math.length(position);
float4 normal = position / distanceToCenter;
BurstContact c = new BurstContact
{
entityA = particleIndex,
entityB = colliderIndex,
point = center + normal * radius,
normal = normal,
};
c.point = transform.TransformPointUnscaled(c.point);
c.normal = transform.TransformDirection(c.normal);
c.distance = distanceToCenter - radius - (shape.contactOffset + BurstMath.EllipsoidRadius(c.normal, orientation, radii.xyz));
contacts.Enqueue(c);
}
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];
// update contact basis:
contact.CalculateBasis(velocities[contact.entityA] - velocities[contact.entityB]);
// update contact masses:
int aMaterialIndex = particleMaterialIndices[contact.entityA];
int bMaterialIndex = particleMaterialIndices[contact.entityB];
bool rollingContacts = (aMaterialIndex >= 0 ? collisionMaterials[aMaterialIndex].rollingContacts > 0 : false) |
(bMaterialIndex >= 0 ? collisionMaterials[bMaterialIndex].rollingContacts > 0 : false);
contact.CalculateContactMassesA(ref invMasses, ref prevPositions, ref prevOrientations, ref invInertiaTensors, rollingContacts);
contact.CalculateContactMassesB(ref invMasses, ref prevPositions, ref prevOrientations, ref invInertiaTensors, rollingContacts);
// update contact distance:
float dAB = math.dot(prevPositions[contact.entityA] - prevPositions[contact.entityB], contact.normal);
float dA = BurstMath.EllipsoidRadius(contact.normal, prevOrientations[contact.entityA], radii[contact.entityA].xyz);
float dB = BurstMath.EllipsoidRadius(contact.normal, prevOrientations[contact.entityB], radii[contact.entityB].xyz);
contact.distance = dAB - (dA + dB);
contacts[i] = contact;
}
}
public void Execute(int i)
{
var contact = contacts[i];
int simplexStart = simplexCounts.GetSimplexStartAndSize(contact.bodyA, out int simplexSize);
// get the material from the first particle in the simplex:
int aMaterialIndex = particleMaterialIndices[simplices[simplexStart]];
bool rollingContacts = aMaterialIndex >= 0 ? collisionMaterials[aMaterialIndex].rollingContacts > 0 : false;
float4 relativeVelocity = float4.zero;
float4 simplexPrevPosition = float4.zero;
quaternion simplexPrevOrientation = new quaternion(0, 0, 0, 0);
float simplexInvMass = 0;
float4 simplexInvInertia = float4.zero;
float simplexRadius = 0;
for (int j = 0; j < simplexSize; ++j)
{
int particleIndex = simplices[simplexStart + j];
relativeVelocity += velocities[particleIndex] * contact.pointA[j];
simplexPrevPosition += prevPositions[particleIndex] * contact.pointA[j];
simplexPrevOrientation.value += prevOrientations[particleIndex].value * contact.pointA[j];
simplexInvMass += invMasses[particleIndex] * contact.pointA[j];
simplexInvInertia += invInertiaTensors[particleIndex] * contact.pointA[j];
simplexRadius += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointA[j];
}
// if there's a rigidbody present, subtract its velocity from the relative velocity:
int rigidbodyIndex = shapes[contact.bodyB].rigidbodyIndex;
if (rigidbodyIndex >= 0)
{
relativeVelocity -= BurstMath.GetRigidbodyVelocityAtPoint(rigidbodyIndex, contact.pointB, rigidbodies, rigidbodyLinearDeltas, rigidbodyAngularDeltas, inertialFrame.frame);
int bMaterialIndex = shapes[contact.bodyB].materialIndex;
rollingContacts |= bMaterialIndex >= 0 ? collisionMaterials[bMaterialIndex].rollingContacts > 0 : false;
}
// update contact distance
contact.distance = math.dot(simplexPrevPosition - contact.pointB, contact.normal) - simplexRadius;
// calculate contact point in A's surface:
float4 contactPoint = contact.pointB + contact.normal * contact.distance;
// update contact orthonormal basis:
contact.CalculateBasis(relativeVelocity);
// calculate A's contact mass.
contact.CalculateContactMassesA(simplexInvMass, simplexInvInertia, simplexPrevPosition, simplexPrevOrientation, contactPoint, rollingContacts);
// calculate B's contact mass.
if (rigidbodyIndex >= 0)
{
contact.CalculateContactMassesB(rigidbodies[rigidbodyIndex], inertialFrame.frame);
}
contacts[i] = contact;
}
public void Execute(int i)
{
var contact = contacts[i];
int aMaterialIndex = particleMaterialIndices[contact.entityA];
bool rollingContacts = aMaterialIndex >= 0 ? collisionMaterials[aMaterialIndex].rollingContacts > 0 : false;
int rigidbodyIndex = shapes[contact.entityB].rigidbodyIndex;
if (rigidbodyIndex >= 0)
{
// update contact basis:
float4 relativeVelocity = velocities[contact.entityA] - BurstMath.GetRigidbodyVelocityAtPoint(rigidbodies[rigidbodyIndex], contact.ContactPointB, rigidbodyLinearDeltas[rigidbodyIndex], rigidbodyAngularDeltas[rigidbodyIndex], inertialFrame.frame);
contact.CalculateBasis(relativeVelocity);
int bMaterialIndex = shapes[contact.entityB].materialIndex;
rollingContacts |= bMaterialIndex >= 0 ? collisionMaterials[bMaterialIndex].rollingContacts > 0 : false;
// update contact masses:
contact.CalculateContactMassesA(ref invMasses, ref prevPositions, ref prevOrientations, ref invInertiaTensors, rollingContacts);
contact.CalculateContactMassesB(rigidbodies[rigidbodyIndex], false);
}
else
{
// update contact basis:
contact.CalculateBasis(velocities[contact.entityA]);
// update contact masses:
contact.CalculateContactMassesA(ref invMasses, ref prevPositions, ref prevOrientations, ref invInertiaTensors, rollingContacts);
}
// update contact distance
float dAB = math.dot(prevPositions[contact.entityA] - contact.point, contact.normal);
float dA = BurstMath.EllipsoidRadius(contact.normal, prevOrientations[contact.entityA], radii[contact.entityA].xyz);
float dB = shapes[contact.entityB].contactOffset;
contact.distance = dAB - (dA + dB);
contacts[i] = contact;
}
private static void BIHTraverse(int particleIndex,
int colliderIndex,
float4 particlePosition,
quaternion particleOrientation,
float4 particleVelocity,
float4 particleRadii,
ref BurstAabb particleBounds,
int nodeIndex,
ref NativeArray <BIHNode> bihNodes,
ref NativeArray <Edge> edges,
ref NativeArray <float2> vertices,
ref EdgeMeshHeader header,
ref BurstAffineTransform colliderToSolver,
ref BurstColliderShape shape,
NativeQueue <BurstContact> .ParallelWriter contacts)
{
var node = bihNodes[header.firstNode + nodeIndex];
// amount by which we should inflate aabbs:
float offset = shape.contactOffset + particleRadii.x;
if (node.firstChild >= 0)
{
// visit min node:
if (particleBounds.min[node.axis] - offset <= node.min)
{
BIHTraverse(particleIndex, colliderIndex,
particlePosition, particleOrientation, particleVelocity, particleRadii, ref particleBounds,
node.firstChild, ref bihNodes, ref edges, ref vertices, ref header,
ref colliderToSolver, ref shape, contacts);
}
// visit max node:
if (particleBounds.max[node.axis] + offset >= node.max)
{
BIHTraverse(particleIndex, colliderIndex,
particlePosition, particleOrientation, particleVelocity, particleRadii, ref particleBounds,
node.firstChild + 1, ref bihNodes, ref edges, ref vertices, ref header,
ref colliderToSolver, ref shape, contacts);
}
}
else
{
// precalculate inverse of velocity vector for ray/aabb intersections:
float4 invDir = math.rcp(particleVelocity);
// contacts against all triangles:
for (int i = node.start; i < node.start + node.count; ++i)
{
Edge t = edges[header.firstEdge + i];
float4 v1 = new float4(vertices[header.firstVertex + t.i1], 0, 0) * colliderToSolver.scale;
float4 v2 = new float4(vertices[header.firstVertex + t.i2], 0, 0) * colliderToSolver.scale;
BurstAabb aabb = new BurstAabb(v1, v2, 0.01f);
aabb.Expand(new float4(offset));
// only generate a contact if the particle trajectory intersects its inflated aabb:
if (aabb.IntersectsRay(particlePosition, invDir, true))
{
float4 point = BurstMath.NearestPointOnEdge(v1, v2, particlePosition);
float4 pointToTri = particlePosition - point;
float distance = math.length(pointToTri);
if (distance > BurstMath.epsilon)
{
BurstContact c = new BurstContact()
{
entityA = particleIndex,
entityB = colliderIndex,
point = colliderToSolver.TransformPointUnscaled(point),
normal = colliderToSolver.TransformDirection(pointToTri / distance),
};
c.distance = distance - (shape.contactOffset + BurstMath.EllipsoidRadius(c.normal, particleOrientation, particleRadii.xyz));
contacts.Enqueue(c);
}
}
}
}
}
public void InteractionTest(int A, int B)
{
bool samePhase = (phases[A] & (int)Oni.ParticleFlags.GroupMask) == (phases[B] & (int)Oni.ParticleFlags.GroupMask);
bool noSelfCollide = (phases[A] & (int)Oni.ParticleFlags.SelfCollide) == 0 || (phases[B] & (int)Oni.ParticleFlags.SelfCollide) == 0;
// only particles of a different phase or set to self-collide can interact.
if (samePhase && noSelfCollide)
{
return;
}
// Predict positions at the end of the whole step:
float4 predictedPositionA = positions[A] + velocities[A] * dt;
float4 predictedPositionB = positions[B] + velocities[B] * dt;
// Calculate particle center distance:
float4 dab = predictedPositionA - predictedPositionB;
float d2 = math.lengthsq(dab);
// if both particles are fluid, check their smoothing radii:
if ((phases[A] & (int)Oni.ParticleFlags.Fluid) != 0 &&
(phases[B] & (int)Oni.ParticleFlags.Fluid) != 0)
{
float fluidDistance = math.max(fluidRadii[A], fluidRadii[B]);
if (d2 <= fluidDistance * fluidDistance)
{
fluidInteractionsQueue.Enqueue(new FluidInteraction {
particleA = A, particleB = B
});
}
}
else // at least one solid particle
{
float solidDistance = radii[A].x + radii[B].x;
// if these particles are self-colliding (have same phase), see if they intersect at rest.
if (samePhase &&
restPositions[A].w > 0.5f &&
restPositions[B].w > 0.5f)
{
// if rest positions intersect, return too.
float sqr_rest_distance = math.lengthsq(restPositions[A] - restPositions[B]);
if (sqr_rest_distance < solidDistance * solidDistance)
{
return;
}
}
// calculate distance at which particles are able to interact:
int matIndexA = particleMaterialIndices[A];
int matIndexB = particleMaterialIndices[B];
float interactionDistance = solidDistance * 1.2f + (matIndexA >= 0 ? collisionMaterials[matIndexA].stickDistance : 0) +
(matIndexB >= 0 ? collisionMaterials[matIndexB].stickDistance : 0);
// if the distance between their predicted positions is smaller than the interaction distance:
if (math.lengthsq(dab) <= interactionDistance * interactionDistance)
{
// calculate contact normal and distance:
float4 normal = positions[A] - positions[B];
float distance = math.length(normal);
if (distance > BurstMath.epsilon)
{
normal /= distance;
float rA = BurstMath.EllipsoidRadius(normal, orientations[A], radii[A].xyz);
float rB = BurstMath.EllipsoidRadius(normal, orientations[B], radii[B].xyz);
// adapt normal for one-sided particles:
if ((phases[A] & (int)Oni.ParticleFlags.OneSided) != 0 &&
(phases[B] & (int)Oni.ParticleFlags.OneSided) != 0)
{
float3 adjustment = float3.zero;
if (rA < rB)
{
adjustment = math.mul(orientations[A], new float3(0, 0, -1));
}
else
{
adjustment = math.mul(orientations[B], new float3(0, 0, 1));
}
float dot = math.dot(normal.xyz, adjustment);
if (dot < 0)
{
normal -= 2 * dot * new float4(adjustment, 0);
}
}
contactsQueue.Enqueue(new BurstContact
{
entityA = A,
entityB = B,
point = positions[B] + normal * rB,
normal = normal,
distance = distance - (rA + rB)
});
}
}
}
}
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(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);
float4 simplexVelocityA = float4.zero;
float4 simplexPrevPositionA = float4.zero;
quaternion simplexPrevOrientationA = new quaternion(0, 0, 0, 0);
float simplexRadiusA = 0;
float simplexInvMassA = 0;
float4 simplexInvInertiaA = float4.zero;
float4 simplexVelocityB = float4.zero;
float4 simplexPrevPositionB = float4.zero;
quaternion simplexPrevOrientationB = new quaternion(0, 0, 0, 0);
float simplexRadiusB = 0;
float simplexInvMassB = 0;
float4 simplexInvInertiaB = float4.zero;
for (int j = 0; j < simplexSizeA; ++j)
{
int particleIndex = simplices[simplexStartA + j];
simplexVelocityA += velocities[particleIndex] * contact.pointA[j];
simplexPrevPositionA += prevPositions[particleIndex] * contact.pointA[j];
simplexPrevOrientationA.value += prevOrientations[particleIndex].value * contact.pointA[j];
simplexInvMassA += invMasses[particleIndex] * contact.pointA[j];
simplexInvInertiaA += invInertiaTensors[particleIndex] * 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];
simplexVelocityB += velocities[particleIndex] * contact.pointB[j];
simplexPrevPositionB += prevPositions[particleIndex] * contact.pointB[j];
simplexPrevOrientationB.value += prevOrientations[particleIndex].value * contact.pointB[j];
simplexInvMassB += invMasses[particleIndex] * contact.pointB[j];
simplexInvInertiaB += invInertiaTensors[particleIndex] * contact.pointB[j];
simplexRadiusB += BurstMath.EllipsoidRadius(contact.normal, prevOrientations[particleIndex], radii[particleIndex].xyz) * contact.pointB[j];
}
// update contact distance
float dAB = math.dot(simplexPrevPositionA - simplexPrevPositionB, contact.normal);
contact.distance = dAB - (simplexRadiusA + simplexRadiusB);
// calculate contact points:
float4 contactPointA = simplexPrevPositionB + contact.normal * (contact.distance + simplexRadiusB);
float4 contactPointB = simplexPrevPositionA - contact.normal * (contact.distance + simplexRadiusA);
// update contact basis:
contact.CalculateBasis(simplexVelocityA - simplexVelocityB);
// update contact masses:
int aMaterialIndex = particleMaterialIndices[simplices[simplexStartA]];
int bMaterialIndex = particleMaterialIndices[simplices[simplexStartB]];
bool rollingContacts = (aMaterialIndex >= 0 ? collisionMaterials[aMaterialIndex].rollingContacts > 0 : false) |
(bMaterialIndex >= 0 ? collisionMaterials[bMaterialIndex].rollingContacts > 0 : false);
contact.CalculateContactMassesA(simplexInvMassA, simplexInvInertiaA, simplexPrevPositionA, simplexPrevOrientationA, contactPointA, rollingContacts);
contact.CalculateContactMassesB(simplexInvMassB, simplexInvInertiaB, simplexPrevPositionB, simplexPrevOrientationB, contactPointB, rollingContacts);
contacts[i] = contact;
}
}
public static void Contacts(int particleIndex,
int colliderIndex,
float4 position,
quaternion orientation,
float4 radii,
ref NativeArray <float> heightMap,
HeightFieldHeader header,
BurstAffineTransform colliderToSolver,
BurstColliderShape shape,
NativeQueue <BurstContact> .ParallelWriter contacts)
{
float4 pos = colliderToSolver.InverseTransformPoint(position);
BurstContact c = new BurstContact
{
entityA = particleIndex,
entityB = colliderIndex,
};
int resolutionU = (int)shape.center.x;
int resolutionV = (int)shape.center.y;
// calculate terrain cell size:
float cellWidth = shape.size.x / (resolutionU - 1);
float cellHeight = shape.size.z / (resolutionV - 1);
// calculate particle bounds min/max cells:
int2 min = new int2((int)math.floor((pos[0] - radii[0]) / cellWidth), (int)math.floor((pos[2] - radii[0]) / cellHeight));
int2 max = new int2((int)math.floor((pos[0] + radii[0]) / cellWidth), (int)math.floor((pos[2] + radii[0]) / cellHeight));
for (int su = min[0]; su <= max[0]; ++su)
{
if (su >= 0 && su < resolutionU - 1)
{
for (int sv = min[1]; sv <= max[1]; ++sv)
{
if (sv >= 0 && sv < resolutionV - 1)
{
// calculate neighbor sample indices:
int csu1 = math.clamp(su + 1, 0, resolutionU - 1);
int csv1 = math.clamp(sv + 1, 0, resolutionV - 1);
// sample heights:
float h1 = heightMap[header.firstSample + sv * resolutionU + su] * shape.size.y;
float h2 = heightMap[header.firstSample + sv * resolutionU + csu1] * shape.size.y;
float h3 = heightMap[header.firstSample + csv1 * resolutionU + su] * shape.size.y;
float h4 = heightMap[header.firstSample + csv1 * resolutionU + csu1] * shape.size.y;
float min_x = su * shape.size.x / (resolutionU - 1);
float max_x = csu1 * shape.size.x / (resolutionU - 1);
float min_z = sv * shape.size.z / (resolutionV - 1);
float max_z = csv1 * shape.size.z / (resolutionV - 1);
// contact with the first triangle:
float4 pointOnTri = BurstMath.NearestPointOnTri(new float4(min_x, h3, max_z, 0),
new float4(max_x, h4, max_z, 0),
new float4(min_x, h1, min_z, 0),
pos);
float4 normal = pos - pointOnTri;
float distance = math.length(normal);
if (distance > BurstMath.epsilon)
{
c.normal = normal / distance;
c.point = pointOnTri;
c.normal = colliderToSolver.TransformDirection(c.normal);
c.point = colliderToSolver.TransformPoint(c.point);
c.distance = distance - (shape.contactOffset + BurstMath.EllipsoidRadius(c.normal, orientation, radii.xyz));
contacts.Enqueue(c);
}
// contact with the second triangle:
pointOnTri = BurstMath.NearestPointOnTri(new float4(min_x, h1, min_z, 0),
new float4(max_x, h4, max_z, 0),
new float4(max_x, h2, min_z, 0),
pos);
normal = pos - pointOnTri;
distance = math.length(normal);
if (distance > BurstMath.epsilon)
{
c.normal = normal / distance;
c.point = pointOnTri;
c.normal = colliderToSolver.TransformDirection(c.normal);
c.point = colliderToSolver.TransformPoint(c.point);
c.distance = distance - (shape.contactOffset + BurstMath.EllipsoidRadius(c.normal, orientation, radii.xyz));
contacts.Enqueue(c);
}
}
}
}
}
}
public static void Contacts(int particleIndex,
float4 position,
quaternion orientation,
float4 radii,
int colliderIndex,
BurstAffineTransform transform,
BurstColliderShape shape,
NativeQueue <BurstContact> .ParallelWriter contacts)
{
BurstContact c = new BurstContact()
{
entityA = particleIndex,
entityB = colliderIndex,
};
float4 center = shape.center * transform.scale;
position = transform.InverseTransformPointUnscaled(position) - center;
int direction = (int)shape.size.z;
float radius = shape.size.x * math.max(transform.scale[(direction + 1) % 3], transform.scale[(direction + 2) % 3]);
float height = math.max(radius, shape.size.y * 0.5f * transform.scale[direction]);
float d = position[direction];
float4 axisProj = float4.zero;
float4 cap = float4.zero;
axisProj[direction] = d;
cap[direction] = height - radius;
float4 centerToPoint;
float centerToPointNorm;
if (d > height - radius)
{ //one cap
centerToPoint = position - cap;
centerToPointNorm = math.length(centerToPoint);
c.distance = centerToPointNorm - radius;
c.normal = (centerToPoint / (centerToPointNorm + math.FLT_MIN_NORMAL));
c.point = cap + c.normal * radius;
}
else if (d < -height + radius)
{ // other cap
centerToPoint = position + cap;
centerToPointNorm = math.length(centerToPoint);
c.distance = centerToPointNorm - radius;
c.normal = (centerToPoint / (centerToPointNorm + math.FLT_MIN_NORMAL));
c.point = -cap + c.normal * radius;
}
else
{//cylinder
centerToPoint = position - axisProj;
centerToPointNorm = math.length(centerToPoint);
c.distance = centerToPointNorm - radius;
c.normal = (centerToPoint / (centerToPointNorm + math.FLT_MIN_NORMAL));
c.point = axisProj + c.normal * radius;
}
c.point += center;
c.point = transform.TransformPointUnscaled(c.point);
c.normal = transform.TransformDirection(c.normal);
c.distance -= shape.contactOffset + BurstMath.EllipsoidRadius(c.normal, orientation, radii.xyz);
contacts.Enqueue(c);
}
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 static void Contacts(int particleIndex,
int colliderIndex,
float4 position,
quaternion orientation,
float4 radii,
ref NativeArray <BurstDFNode> dfNodes,
DistanceFieldHeader header,
BurstAffineTransform colliderToSolver,
BurstColliderShape shape,
NativeQueue <BurstContact> .ParallelWriter contacts)
{
float4 pos = colliderToSolver.InverseTransformPoint(position);
BurstContact c = new BurstContact
{
entityA = particleIndex,
entityB = colliderIndex,
};
float4 sample = DFTraverse(pos, 0, ref header, ref dfNodes);
c.normal = new float4(math.normalize(sample.xyz), 0);
c.point = pos - c.normal * sample[3];
c.normal = colliderToSolver.TransformDirection(c.normal);
c.point = colliderToSolver.TransformPoint(c.point);
c.distance = sample[3] * math.cmax(colliderToSolver.scale.xyz) - (shape.contactOffset + BurstMath.EllipsoidRadius(c.normal, orientation, radii.xyz));
contacts.Enqueue(c);
}
public static void Contacts(int particleIndex,
float4 position,
quaternion orientation,
float4 radii,
int colliderIndex,
BurstAffineTransform transform,
BurstColliderShape shape,
NativeQueue <BurstContact> .ParallelWriter contacts)
{
BurstContact c = new BurstContact()
{
entityA = particleIndex,
entityB = colliderIndex,
};
float4 center = shape.center * transform.scale;
float4 size = shape.size * transform.scale * 0.5f;
position = transform.InverseTransformPointUnscaled(position) - center;
// Get minimum distance for each axis:
float4 distances = size - math.abs(position);
// if we are inside the box:
if (distances.x >= 0 && distances.y >= 0 && distances.z >= 0)
{
// find minimum distance in all three axes and the axis index:
float min = float.MaxValue;
int axis = 0;
for (int i = 0; i < 3; ++i)
{
if (distances[i] < min)
{
min = distances[i];
axis = i;
}
}
c.normal = float4.zero;
c.point = position;
c.distance = -distances[axis];
c.normal[axis] = position[axis] > 0 ? 1 : -1;
c.point[axis] = size[axis] * c.normal[axis];
}
else // we are outside the box:
{
// clamp point to be inside the box:
c.point = math.clamp(position, -size, size);
// find distance and direction to clamped point:
float4 diff = position - c.point;
c.distance = math.length(diff);
c.normal = diff / (c.distance + math.FLT_MIN_NORMAL);
}
c.point += center;
c.point = transform.TransformPointUnscaled(c.point);
c.normal = transform.TransformDirection(c.normal);
c.distance -= shape.contactOffset + BurstMath.EllipsoidRadius(c.normal, orientation, radii.xyz);
contacts.Enqueue(c);
}
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;
}
}