public static IShape CreateShape(Transform o2w, Transform w2o, bool reverseOrientation, ParameterSet parameters, Dictionary<string, ITexture<double>> floatTextures, Dictionary<string, ITexture<Spectrum>> spectrumTextures)
{
int nvi = 0, npi = 0, nuvi = 0, nsi = 0, nni = 0;
int[] vi = parameters.FindInt ("indices", ref nvi);
Point[] P = parameters.FindPoint ("P", ref npi);
double[] uvs = parameters.FindDouble ("uv", ref nuvi);
if (uvs == null)
uvs = parameters.FindDouble ("st", ref nuvi);
bool discardDegnerateUVs = parameters.FindOneBool ("discarddegenerateUVs", false);
// XXX should complain if uvs aren't an array of 2...
if (uvs != null)
{
if (nuvi < 2 * npi)
{
uvs = null;
}
}
if (vi == null || P == null)
return null;
Vector[] S = parameters.FindVector ("S", ref nsi);
if (S != null && nsi != npi)
{
S = null;
}
Normal[] N = parameters.FindNormal ("N", ref nni);
if (N != null && nni != npi)
{
N = null;
}
if (discardDegnerateUVs && uvs != null && N != null)
{
// if there are normals, check for bad uv's that
// give degenerate mappings; discard them if so
int vp = 0;
for (int i = 0; i < nvi; i += 3,vp += 3)
{
double area = 0.5 * ((P[vi[vp + 0]] - P[vi[vp + 1]]) % (P[vi[vp + 2]] - P[vi[vp + 1]])).Length;
if (area < 1E-07)
continue;
// ignore degenerate tris.
if ((uvs[2 * vi[vp + 0]] == uvs[2 * vi[vp + 1]] && uvs[2 * vi[vp + 0] + 1] == uvs[2 * vi[vp + 1] + 1]) || (uvs[2 * vi[vp + 1]] == uvs[2 * vi[vp + 2]] && uvs[2 * vi[vp + 1] + 1] == uvs[2 * vi[vp + 2] + 1]) || (uvs[2 * vi[vp + 2]] == uvs[2 * vi[vp + 0]] && uvs[2 * vi[vp + 2] + 1] == uvs[2 * vi[vp + 0] + 1]))
{
uvs = null;
break;
}
}
}
for (int i = 0; i < nvi; ++i)
if (vi[i] >= npi)
{
return null;
}
ITexture<double> alphaTex = null;
string alphaTexName = parameters.FindTexture ("alpha");
if (alphaTexName != "")
{
if (floatTextures.ContainsKey (alphaTexName))
alphaTex = floatTextures[alphaTexName];
} else if (parameters.FindOneDouble ("alpha", 1.0) == 0.0)
alphaTex = new ConstantTexture<double> (0.0);
return new TriangleMesh (o2w, w2o, reverseOrientation, nvi / 3, npi, vi, P, N, S, uvs,
alphaTex);
}