// create a particle mesh by fitting points on an implicit surface defined by a signed distance field
public ParticleMesh(Func <Vector3, float> dist_func, Vector3 domain_hsize, Vector3 domain_offset, int particle_count, float quality)
{
// store stuff
Vector3 p;
float D;
// hard-limit on sample count, to avoid infinite sampling when the distance function is positive everywhere
int sample_limit = particle_count * 1000;
// divide once
float thickness = 1.0f / quality;
// preallocate position container
points = new List <Vector3>(particle_count);
// particle-fitting
int samples = 0;
int i = 0;
while (i < particle_count && samples < sample_limit)
{
// generate random position inside bounding volume
p.x = Lib.FastRandomFloat() * domain_hsize.x + domain_offset.x;
p.y = Lib.FastRandomFloat() * domain_hsize.y + domain_offset.y;
p.z = Lib.FastRandomFloat() * domain_hsize.z + domain_offset.z;
// calculate signed distance
D = dist_func(p);
if (D <= 0.0f) // if inside
{
// this displays the exact radiation field border
if (D <= 0.0 && D > -thickness)
{
points.Add(p);
++i;
}
}
// count samples
++samples;
}
// some feedback on the samples going above the limit
if (i < particle_count)
{
Lib.Log("particle-fitting reached hard limit at " + Lib.HumanReadablePerc((double)i / (double)particle_count));
}
}