Function NvFlexExtTearClothMesh

extensions/flexExtCloth.cpp:256–343

}

void NvFlexExtTearClothMesh(NvFlexExtAsset* asset, float maxStrain, int maxSplits, NvFlexExtTearingParticleClone* particleCopies, int* numParticleCopies,  int maxCopies, NvFlexExtTearingMeshEdit* triangleEdits, int* numTriangleEdits, int maxEdits) 
{
	FlexExtTearingClothAsset* tearable = (FlexExtTearingClothAsset*)asset;
	
	std::vector<ClothMesh::TriangleUpdate> edits;
	std::vector<ClothMesh::VertexCopy> copies;

	int splits = 0;

	maxCopies = Min(maxCopies, tearable->maxParticles-tearable->numParticles);

	// iterate over all edges and tear if beyond maximum strain
	for (int i=0; i < tearable->numSprings && int(copies.size()) < maxCopies && splits < maxSplits; ++i)
	{
		int a = tearable->springIndices[i*2+0];
		int b = tearable->springIndices[i*2+1];

		Vec3 p = Vec3(&tearable->particles[a*4]);
		Vec3 q = Vec3(&tearable->particles[b*4]);

		// check strain and break if greater than max threshold
		if (Length(p-q) > tearable->springRestLengths[i]*maxStrain)
		{
			// skip fixed particles
			if (Vec4(&tearable->particles[a*4]).w == 0.0f)
				continue;

			if (Vec4(&tearable->particles[b*4]).w == 0.0f)
				continue;

			// choose vertex of edge to split
			const int splitIndex = Randf() > 0.5f ? a : b;
			const Vec3 splitPlane = Normalize(p-q);	// todo: use plane perpendicular to normal and edge..

			std::vector<int> adjacentTriangles;
			std::vector<int> adjacentVertices;

			const int newIndex = tearable->mMesh->SplitVertex((Vec4*)tearable->particles, splitIndex, splitPlane, adjacentTriangles, adjacentVertices, edits, copies, maxCopies-int(copies.size()));

			if (newIndex != -1)
			{
				++splits;

				// separate each adjacent vertex if it is now singular
				for (int s=0; s < int(adjacentVertices.size()); ++s)
				{
					const int adjacentVertex = adjacentVertices[s];

					tearable->mMesh->SeparateVertex(adjacentVertex, edits, copies, maxCopies-int(copies.size()));
				}

				// also test the new vertex which can become singular
				tearable->mMesh->SeparateVertex(newIndex, edits, copies, maxCopies-int(copies.size()));
			}
		}
	}

	// update asset particle count