Function CreateClusters

extensions/flexExtSoft.cpp:185–273

};

int CreateClusters(Vec3* particles, const float* priority, int numParticles, std::vector<int>& outClusterOffsets, std::vector<int>& outClusterIndices, std::vector<Vec3>& outClusterPositions, float radius, float smoothing = 0.0f)
{
	std::vector<Seed> seeds;
	std::vector<Cluster> clusters;

	// flags a particle as belonging to at least one cluster
	std::vector<bool> used(numParticles, false);

	// initialize seeds
	for (int i = 0; i < numParticles; ++i)
	{
		Seed s;
		s.index = i;
		s.priority = priority[i];

		seeds.push_back(s);
	}

	// sort seeds on priority
	std::stable_sort(seeds.begin(), seeds.end());

	SweepAndPrune sap(particles, numParticles);

	while (seeds.size())
	{
		// pick highest unused particle from the seeds list
		Seed seed = seeds.back();
		seeds.pop_back();

		if (!used[seed.index])
		{
			Cluster c;

			sap.QuerySphere(Vec3(particles[seed.index]), radius, c.indices);
			
			// mark overlapping particles as used so they are removed from the list of potential cluster seeds
			for (int i=0; i < int(c.indices.size()); ++i)
				used[c.indices[i]] = true;

			c.mean = CalculateMean(particles, &c.indices[0], int(c.indices.size()));

			clusters.push_back(c);
		}
	}

	if (smoothing > 0.0f)
	{
		for (int i = 0; i < int(clusters.size()); ++i)
		{
			Cluster& c = clusters[i];

			// clear cluster indices
			c.indices.resize(0);

			// calculate cluster particles using cluster mean and smoothing radius
			sap.QuerySphere(c.mean, smoothing, c.indices);

			c.mean = CalculateMean(particles, &c.indices[0], int(c.indices.size()));