/**
* Generates new valid rest positions for the entire rope.
*/
public override void RegenerateRestPositions()
{
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
// Iterate trough all distance constraints in order:
int particle = -1;
int lastParticle = -1;
float accumulatedDistance = 0;
for (int i = 0; i < distanceBatch.ConstraintCount; ++i)
{
if (i == 0)
{
lastParticle = particle = distanceBatch.springIndices[i * 2];
restPositions[particle] = new Vector4(0, 0, 0, 1);
}
accumulatedDistance += Mathf.Min(interParticleDistance, principalRadii[particle][0], principalRadii[lastParticle][0]);
particle = distanceBatch.springIndices[i * 2 + 1];
restPositions[particle] = Vector3.right * accumulatedDistance;
restPositions[particle][3] = 1; // activate rest position
}
PushDataToSolver(ParticleData.REST_POSITIONS);
}
/**
* Counts the amount of continuous sections in each chunk of rope.
*/
protected void CountContinuousSegments()
{
rawCurves.Clear();
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
int segmentCount = 0;
int lastParticle = -1;
// Iterate trough all distance constraints in order. If we find a discontinuity, reset segment count:
for (int i = 0; i < distanceBatch.ConstraintCount; ++i)
{
int particle1 = distanceBatch.springIndices[i * 2];
int particle2 = distanceBatch.springIndices[i * 2 + 1];
// start new curve at discontinuities:
if (particle1 != lastParticle && segmentCount > 0)
{
// add a new curve with the correct amount of sections:
AddCurve(segmentCount + 1);
segmentCount = 0;
}
lastParticle = particle2;
segmentCount++;
}
// add the last curve:
AddCurve(segmentCount + 1);
}
/**
* Returns the rest length of a structural constraint
*/
public override float GetStructuralConstraintRestLength(int constraintIndex)
{
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
if (distanceBatch != null && constraintIndex >= 0 && constraintIndex < distanceBatch.ConstraintCount)
{
return(distanceBatch.restLengths[constraintIndex]);
}
return(0);
}
/**
* Returns the index of the structural constraint at a given normalized rope coordinate.
*/
public override int GetConstraintIndexAtNormalizedCoordinate(float coord)
{
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
if (distanceBatch != null)
{
float mu = coord * distanceBatch.ConstraintCount;
return(Mathf.Clamp(Mathf.FloorToInt(mu), 0, distanceBatch.ConstraintCount - 1));
}
return(-1);
}
/**
* Returns the index of the distance constraint at a given normalized rope coordinate.
*/
public int GetConstraintIndexAtNormalizedCoordinate(float coord)
{
// Nothing guarantees particle index order is the same as particle ordering in the rope.
// However distance constraints must be ordered, so we'll use that:
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
float mu = coord * distanceBatch.ConstraintCount;
return(Mathf.Clamp(Mathf.FloorToInt(mu), 0, distanceBatch.ConstraintCount - 1));
}
/**
* Returns the particle indices affected by a structural constraint
*/
public override bool GetStructuralConstraintParticles(int constraintIndex, ref int particleIndex1, ref int particleIndex2)
{
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
if (distanceBatch != null && constraintIndex >= 0 && constraintIndex < distanceBatch.ConstraintCount)
{
particleIndex1 = distanceBatch.springIndices[constraintIndex * 2];
particleIndex2 = distanceBatch.springIndices[constraintIndex * 2 + 1];
return(true);
}
return(false);
}
/**
* Recalculates rest rope length.
*/
public void RecalculateLenght()
{
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
restLength = 0;
// Iterate trough all distance constraints in order:
for (int i = 0; i < distanceBatch.ConstraintCount; ++i)
{
restLength += distanceBatch.restLengths[i];
}
}
/**
* Generate a list of smooth curves using particles as control points. Will take into account cuts in the rope,
* generating one curve for each continuous piece of rope.
*/
public void SmoothCurvesFromParticles()
{
curves.Clear();
curveSections = 0;
curveLength = 0;
// count amount of segments in each rope chunk:
CountContinuousSegments();
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
Matrix4x4 w2l = transform.worldToLocalMatrix;
int firstSegment = 0;
// generate curve for each rope chunk:
for (int i = 0; i < rawCurves.Count; ++i)
{
int segments = rawCurves[i].Count - 1;
// allocate memory for the curve:
ObiList <CurveSection> controlPoints = rawCurves[i];
// get control points position:
for (int m = 0; m < segments; ++m)
{
int particleIndex = distanceBatch.springIndices[(firstSegment + m) * 2];
controlPoints[m] = new CurveSection(w2l.MultiplyPoint3x4(GetParticlePosition(particleIndex)),
solidRadii[particleIndex],
(this.colors != null && particleIndex < this.colors.Length) ? this.colors[particleIndex] : Color.white);
// last segment adds its second particle too:
if (m == segments - 1)
{
particleIndex = distanceBatch.springIndices[(firstSegment + m) * 2 + 1];
controlPoints[m + 1] = new CurveSection(w2l.MultiplyPoint3x4(GetParticlePosition(particleIndex)),
solidRadii[particleIndex],
(this.colors != null && particleIndex < this.colors.Length) ? this.colors[particleIndex] : Color.white);
}
}
firstSegment += segments;
// get smooth curve points:
ChaikinSmoothing(controlPoints, curves[i], smoothing);
// count total curve sections and total curve length:
curveSections += curves[i].Count - 1;
curveLength += CalculateCurveLength(curves[i]);
}
}
/**
* Returns actual rope length, including stretch.
*/
public float CalculateLength()
{
ObiDistanceConstraintBatch batch = DistanceConstraints.GetFirstBatch();
// iterate over all distance constraints and accumulate their length:
float actualLength = 0;
Vector3 a, b;
for (int i = 0; i < batch.ConstraintCount; ++i)
{
a = GetParticlePosition(batch.springIndices[i * 2]);
b = GetParticlePosition(batch.springIndices[i * 2 + 1]);
actualLength += Vector3.Distance(a, b);
}
return(actualLength);
}
private void ApplyTearing()
{
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
float[] forces = new float[distanceBatch.ConstraintCount];
Oni.GetBatchConstraintForces(distanceBatch.OniBatch, forces, distanceBatch.ConstraintCount, 0);
List <TornEdge> tornEdges = new List <TornEdge>();
for (int i = 0; i < forces.Length; i++)
{
float p1Resistance = tearResistance[distanceBatch.springIndices[i * 2]];
float p2Resistance = tearResistance[distanceBatch.springIndices[i * 2 + 1]];
// average particle resistances:
float resistance = (p1Resistance + p2Resistance) * 0.5f * tearResistanceMultiplier;
if (-forces[i] * 1000 > resistance) // units are kilonewtons.
{
tornEdges.Add(new TornEdge(i, forces[i]));
}
}
if (tornEdges.Count > 0)
{
// sort edges by tear force:
tornEdges.Sort(delegate(TornEdge x, TornEdge y) {
return(x.force.CompareTo(y.force));
});
DistanceConstraints.RemoveFromSolver(null);
for (int i = 0; i < Mathf.Min(tearRate, tornEdges.Count); i++)
{
Tear(tornEdges[i].index);
}
DistanceConstraints.AddToSolver(this);
// update active bending constraints:
BendingConstraints.SetActiveConstraints();
// update solver deformable triangle indices:
UpdateDeformableTriangles();
// upload active particle list to solver:
solver.UpdateActiveParticles();
}
}
protected void ApplyTearing()
{
if (!tearable)
{
return;
}
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
float[] forces = new float[distanceBatch.ConstraintCount];
Oni.GetBatchConstraintForces(distanceBatch.OniBatch, forces, distanceBatch.ConstraintCount, 0);
List <int> tearedEdges = new List <int>();
for (int i = 0; i < forces.Length; i++)
{
float p1Resistance = tearResistance[distanceBatch.springIndices[i * 2]];
float p2Resistance = tearResistance[distanceBatch.springIndices[i * 2 + 1]];
// average particle resistances:
float resistance = (p1Resistance + p2Resistance) * 0.5f * tearResistanceMultiplier;
if (-forces[i] * 1000 > resistance) // units are kilonewtons.
{
tearedEdges.Add(i);
}
}
if (tearedEdges.Count > 0)
{
DistanceConstraints.RemoveFromSolver(null);
BendingConstraints.RemoveFromSolver(null);
for (int i = 0; i < tearedEdges.Count; i++)
{
Tear(tearedEdges[i]);
}
BendingConstraints.AddToSolver(this);
DistanceConstraints.AddToSolver(this);
// update active bending constraints:
BendingConstraints.SetActiveConstraints();
// upload active particle list to solver:
solver.UpdateActiveParticles();
}
}
public void Tear(int constraintIndex)
{
// don't allow splitting if there are no free particles left in the pool.
if (usedParticles >= totalParticles)
{
return;
}
// get involved constraint batches:
ObiDistanceConstraintBatch distanceBatch = (ObiDistanceConstraintBatch)DistanceConstraints.GetFirstBatch();
ObiBendConstraintBatch bendingBatch = (ObiBendConstraintBatch)BendingConstraints.GetFirstBatch();
// get particle indices at both ends of the constraint:
int splitIndex = distanceBatch.springIndices[constraintIndex * 2];
int intactIndex = distanceBatch.springIndices[constraintIndex * 2 + 1];
// see if the rope is continuous at the split index and the intact index:
bool continuousAtSplit = (constraintIndex < distanceBatch.ConstraintCount - 1 && distanceBatch.springIndices[(constraintIndex + 1) * 2] == splitIndex) ||
(constraintIndex > 0 && distanceBatch.springIndices[(constraintIndex - 1) * 2 + 1] == splitIndex);
bool continuousAtIntact = (constraintIndex < distanceBatch.ConstraintCount - 1 && distanceBatch.springIndices[(constraintIndex + 1) * 2] == intactIndex) ||
(constraintIndex > 0 && distanceBatch.springIndices[(constraintIndex - 1) * 2 + 1] == intactIndex);
// we will split the particle with higher mass, so swap them if needed (and possible). Also make sure that the rope hasnt been cut there yet:
if ((invMasses[splitIndex] > invMasses[intactIndex] || invMasses[splitIndex] == 0) &&
continuousAtIntact)
{
int aux = splitIndex;
splitIndex = intactIndex;
intactIndex = aux;
}
// see if we are able to proceed with the cut:
if (invMasses[splitIndex] == 0 || !continuousAtSplit)
{
return;
}
// halve the mass of the teared particle:
invMasses[splitIndex] *= 2;
// copy the new particle data in the actor and solver arrays:
positions[usedParticles] = positions[splitIndex];
velocities[usedParticles] = velocities[splitIndex];
active[usedParticles] = active[splitIndex];
invMasses[usedParticles] = invMasses[splitIndex];
principalRadii[usedParticles] = principalRadii[splitIndex];
phases[usedParticles] = phases[splitIndex];
if (colors != null && colors.Length > 0)
{
colors[usedParticles] = colors[splitIndex];
}
tearResistance[usedParticles] = tearResistance[splitIndex];
restPositions[usedParticles] = positions[splitIndex];
restPositions[usedParticles][3] = 1; // activate rest position.
// update solver particle data:
solver.velocities[particleIndices[usedParticles]] = solver.velocities[particleIndices[splitIndex]];
solver.startPositions[particleIndices[usedParticles]] = solver.positions [particleIndices[usedParticles]] = solver.positions [particleIndices[splitIndex]];
solver.invMasses [particleIndices[usedParticles]] = solver.invMasses [particleIndices[splitIndex]] = invMasses[splitIndex];
solver.principalRadii[particleIndices[usedParticles]] = solver.principalRadii[particleIndices[splitIndex]] = principalRadii[splitIndex];
solver.phases [particleIndices[usedParticles]] = solver.phases [particleIndices[splitIndex]];
// Update bending constraints:
for (int i = 0; i < bendingBatch.ConstraintCount; ++i)
{
// disable the bending constraint centered at the split particle:
if (bendingBatch.bendingIndices[i * 3 + 2] == splitIndex)
{
bendingBatch.DeactivateConstraint(i);
}
// update the one that bridges the cut:
else if (!DoesBendConstraintSpanDistanceConstraint(distanceBatch, bendingBatch, constraintIndex, i))
{
// if the bend constraint does not involve the split distance constraint,
// update the end that references the split vertex:
if (bendingBatch.bendingIndices[i * 3] == splitIndex)
{
bendingBatch.bendingIndices[i * 3] = usedParticles;
}
else if (bendingBatch.bendingIndices[i * 3 + 1] == splitIndex)
{
bendingBatch.bendingIndices[i * 3 + 1] = usedParticles;
}
}
}
// Update distance constraints at both ends of the cut:
if (constraintIndex < distanceBatch.ConstraintCount - 1)
{
if (distanceBatch.springIndices[(constraintIndex + 1) * 2] == splitIndex)
{
distanceBatch.springIndices[(constraintIndex + 1) * 2] = usedParticles;
}
if (distanceBatch.springIndices[(constraintIndex + 1) * 2 + 1] == splitIndex)
{
distanceBatch.springIndices[(constraintIndex + 1) * 2 + 1] = usedParticles;
}
}
if (constraintIndex > 0)
{
if (distanceBatch.springIndices[(constraintIndex - 1) * 2] == splitIndex)
{
distanceBatch.springIndices[(constraintIndex - 1) * 2] = usedParticles;
}
if (distanceBatch.springIndices[(constraintIndex - 1) * 2 + 1] == splitIndex)
{
distanceBatch.springIndices[(constraintIndex - 1) * 2 + 1] = usedParticles;
}
}
usedParticles++;
pooledParticles--;
}
/**
* Returns the amount of structural constraints in the rope.
*/
public override int GetStructuralConstraintCount()
{
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
return(distanceBatch != null ? distanceBatch.ConstraintCount : 0);
}
/**
* Tears a cloth distance constraint, affecting both the physical representation of the cloth and its mesh.
*/
public void Tear(int constraintIndex)
{
if (topology == null)
{
return;
}
// don't allow splitting if there are no free particles left in the pool.
if (usedParticles >= sharedMesh.vertexCount + pooledVertices)
{
return;
}
// get involved constraint batches:
ObiDistanceConstraintBatch distanceBatch = DistanceConstraints.GetFirstBatch();
ObiBendConstraintBatch bendingBatch = BendingConstraints.GetFirstBatch();
// get particle indices at both ends of the constraint:
int splitIndex = distanceBatch.springIndices[constraintIndex * 2];
int intactIndex = distanceBatch.springIndices[constraintIndex * 2 + 1];
// we will split the particle with higher mass, so swap them if needed.
if (invMasses[splitIndex] > invMasses[intactIndex])
{
int aux = splitIndex;
splitIndex = intactIndex;
intactIndex = aux;
}
// Calculate the splitting plane in local space:
Vector3 v1 = transform.worldToLocalMatrix.MultiplyPoint3x4(solver.renderablePositions[particleIndices[splitIndex]]);
Vector3 v2 = transform.worldToLocalMatrix.MultiplyPoint3x4(solver.renderablePositions[particleIndices[intactIndex]]);
Vector3 normal = (v2 - v1).normalized;
int numUpdatedHalfEdges = maxVertexValency;
int[] updatedHalfEdges = new int[numUpdatedHalfEdges];
// Try to split the vertex at that particle.
// If we cannot not split the higher mass particle, try the other one. If that fails too, we cannot tear this edge.
if (invMasses[splitIndex] == 0 ||
!Oni.TearDeformableMeshAtVertex(deformableMesh, splitIndex, ref v1, ref normal, updatedHalfEdges, ref numUpdatedHalfEdges))
{
// Try to split the other particle:
int aux = splitIndex;
splitIndex = intactIndex;
intactIndex = aux;
v1 = transform.worldToLocalMatrix.MultiplyPoint3x4(solver.renderablePositions[particleIndices[splitIndex]]);
v2 = transform.worldToLocalMatrix.MultiplyPoint3x4(solver.renderablePositions[particleIndices[intactIndex]]);
normal = (v2 - v1).normalized;
if (invMasses[splitIndex] == 0 ||
!Oni.TearDeformableMeshAtVertex(deformableMesh, splitIndex, ref v1, ref normal, updatedHalfEdges, ref numUpdatedHalfEdges))
{
return;
}
}
// identify weak points around the cut:
int weakPt1 = -1;
int weakPt2 = -1;
float weakestValue = float.MaxValue;
float secondWeakestValue = float.MaxValue;
foreach (Oni.Vertex v in topology.GetNeighbourVerticesEnumerator(topology.heVertices[splitIndex]))
{
Vector3 neighbour = transform.worldToLocalMatrix.MultiplyPoint3x4(solver.renderablePositions[particleIndices[v.index]]);
float weakness = Mathf.Abs(Vector3.Dot(normal, (neighbour - v1).normalized));
if (weakness < weakestValue)
{
secondWeakestValue = weakestValue;
weakestValue = weakness;
weakPt2 = weakPt1;
weakPt1 = v.index;
}
else if (weakness < secondWeakestValue)
{
secondWeakestValue = weakness;
weakPt2 = v.index;
}
}
// reduce tear resistance at the weak spots of the cut, to encourage coherent tear formation.
if (weakPt1 >= 0)
{
tearResistance[weakPt1] *= 1 - tearDebilitation;
}
if (weakPt2 >= 0)
{
tearResistance[weakPt2] *= 1 - tearDebilitation;
}
topology.UpdateVertexCount();
// halve the mass and radius of the original particle:
invMasses[splitIndex] *= 2;
solidRadii[splitIndex] *= 0.5f;
// copy the new particle data in the actor and solver arrays:
positions[usedParticles] = positions[splitIndex];
velocities[usedParticles] = velocities[splitIndex];
active[usedParticles] = active[splitIndex];
invMasses[usedParticles] = invMasses[splitIndex];
solidRadii[usedParticles] = solidRadii[splitIndex];
phases[usedParticles] = phases[splitIndex];
areaContribution[usedParticles] = areaContribution[splitIndex];
tearResistance[usedParticles] = tearResistance[splitIndex];
restPositions[usedParticles] = positions[splitIndex];
restPositions[usedParticles][3] = 0; // activate rest position.
// update solver particle data:
Vector4[] velocity = { Vector4.zero };
Oni.GetParticleVelocities(solver.OniSolver, velocity, 1, particleIndices[splitIndex]);
Oni.SetParticleVelocities(solver.OniSolver, velocity, 1, particleIndices[usedParticles]);
Vector4[] position = { Vector4.zero };
Oni.GetParticlePositions(solver.OniSolver, position, 1, particleIndices[splitIndex]);
Oni.SetParticlePositions(solver.OniSolver, position, 1, particleIndices[usedParticles]);
Oni.SetParticleInverseMasses(solver.OniSolver, new float[] { invMasses[splitIndex] }, 1, particleIndices[usedParticles]);
Oni.SetParticleSolidRadii(solver.OniSolver, new float[] { solidRadii[splitIndex] }, 1, particleIndices[usedParticles]);
Oni.SetParticlePhases(solver.OniSolver, new int[] { phases[splitIndex] }, 1, particleIndices[usedParticles]);
usedParticles++;
// update distance constraints:
for (int i = 0; i < numUpdatedHalfEdges; ++i)
{
int halfEdgeIndex = updatedHalfEdges[i];
Oni.HalfEdge e = topology.heHalfEdges[halfEdgeIndex];
// find start and end vertex indices for this edge:
int startVertex = topology.GetHalfEdgeStartVertex(topology.heHalfEdges[halfEdgeIndex]);
int endVertex = topology.heHalfEdges[halfEdgeIndex].endVertex;
if (distanceConstraintMap[halfEdgeIndex] > -1) // update existing edge
{
distanceBatch.springIndices[distanceConstraintMap[halfEdgeIndex] * 2] = startVertex;
distanceBatch.springIndices[distanceConstraintMap[halfEdgeIndex] * 2 + 1] = endVertex;
}
else if (topology.IsSplit(halfEdgeIndex)) // new edge
{
int pairConstraintIndex = distanceConstraintMap[topology.heHalfEdges[halfEdgeIndex].pair];
// update constraint-edge map:
distanceConstraintMap[halfEdgeIndex] = distanceBatch.restLengths.Count;
// add the new constraint:
distanceBatch.AddConstraint(startVertex,
endVertex,
distanceBatch.restLengths[pairConstraintIndex],
distanceBatch.stiffnesses[pairConstraintIndex].x,
distanceBatch.stiffnesses[pairConstraintIndex].y);
}
// update deformable triangles:
if (e.indexInFace > -1)
{
deformableTriangles[e.face * 3 + e.indexInFace] = e.endVertex;
}
}
if (splitIndex < bendConstraintOffsets.Length - 1)
{
// deactivate bend constraints that contain the split vertex...
// ...at the center:
for (int i = bendConstraintOffsets[splitIndex]; i < bendConstraintOffsets[splitIndex + 1]; ++i)
{
bendingBatch.DeactivateConstraint(i);
}
// ...at one end:
foreach (Oni.Vertex v in topology.GetNeighbourVerticesEnumerator(topology.heVertices[splitIndex]))
{
if (v.index < bendConstraintOffsets.Length - 1)
{
for (int i = bendConstraintOffsets[v.index]; i < bendConstraintOffsets[v.index + 1]; ++i)
{
if (bendingBatch.bendingIndices[i * 3] == splitIndex || bendingBatch.bendingIndices[i * 3 + 1] == splitIndex)
{
bendingBatch.DeactivateConstraint(i);
}
}
}
}
}
}
