std::vector<std::shared_ptr<Shape>> CreateTriangleMeshShape(
const Transform *o2w, const Transform *w2o, bool reverseOrientation,
const ParamSet ¶ms,
std::map<std::string, std::shared_ptr<Texture<Float>>> *floatTextures) {
int nvi, npi, nuvi, nsi, nni;
const int *vi = params.FindInt("indices", &nvi);
const Point3f *P = params.FindPoint3f("P", &npi);
const Point2f *uvs = params.FindPoint2f("uv", &nuvi);
if (!uvs) uvs = params.FindPoint2f("st", &nuvi);
std::vector<Point2f> tempUVs;
if (!uvs) {
const Float *fuv = params.FindFloat("uv", &nuvi);
if (!fuv) fuv = params.FindFloat("st", &nuvi);
if (fuv) {
nuvi /= 2;
tempUVs.reserve(nuvi);
for (int i = 0; i < nuvi; ++i)
tempUVs.push_back(Point2f(fuv[2 * i], fuv[2 * i + 1]));
uvs = &tempUVs[0];
}
}
bool discardDegenerateUVs =
params.FindOneBool("discarddegenerateUVs", false);
if (uvs) {
if (nuvi < npi) {
Error(
"Not enough of \"uv\"s for triangle mesh. Expencted %d, "
"found %d. Discarding.",
npi, nuvi);
uvs = nullptr;
} else if (nuvi > npi)
Warning(
"More \"uv\"s provided than will be used for triangle "
"mesh. (%d expcted, %d found)",
npi, nuvi);
}
if (!vi) {
Error(
"Vertex indices \"indices\" not provided with triangle mesh shape");
return std::vector<std::shared_ptr<Shape>>();
}
if (!P) {
Error("Vertex positions \"P\" not provided with triangle mesh shape");
return std::vector<std::shared_ptr<Shape>>();
}
const Vector3f *S = params.FindVector3f("S", &nsi);
if (S && nsi != npi) {
Error("Number of \"S\"s for triangle mesh must match \"P\"s");
S = nullptr;
}
const Normal3f *N = params.FindNormal3f("N", &nni);
if (N && nni != npi) {
Error("Number of \"N\"s for triangle mesh must match \"P\"s");
N = nullptr;
}
if (discardDegenerateUVs && uvs && N) {
// if there are normals, check for bad uv's that
// give degenerate mappings; discard them if so
const int *vp = vi;
for (int i = 0; i < nvi; i += 3, vp += 3) {
Float area =
.5f * Cross(P[vp[0]] - P[vp[1]], P[vp[2]] - P[vp[1]]).Length();
if (area < 1e-7) continue; // ignore degenerate tris.
if ((uvs[vp[0]].x == uvs[vp[1]].x &&
uvs[vp[0]].y == uvs[vp[1]].y) ||
(uvs[vp[1]].x == uvs[vp[2]].x &&
uvs[vp[1]].y == uvs[vp[2]].y) ||
(uvs[vp[2]].x == uvs[vp[0]].x &&
uvs[vp[2]].y == uvs[vp[0]].y)) {
Warning(
"Degenerate uv coordinates in triangle mesh. Discarding "
"all uvs.");
uvs = nullptr;
break;
}
}
}
for (int i = 0; i < nvi; ++i)
if (vi[i] >= npi) {
Error(
"trianglemesh has out of-bounds vertex index %d (%d \"P\" "
"values were given",
vi[i], npi);
return std::vector<std::shared_ptr<Shape>>();
}
std::shared_ptr<Texture<Float>> alphaTex;
std::string alphaTexName = params.FindTexture("alpha");
if (alphaTexName != "") {
if (floatTextures->find(alphaTexName) != floatTextures->end())
alphaTex = (*floatTextures)[alphaTexName];
else
Error("Couldn't find float texture \"%s\" for \"alpha\" parameter",
alphaTexName.c_str());
} else if (params.FindOneFloat("alpha", 1.f) == 0.f)
alphaTex.reset(new ConstantTexture<Float>(0.f));
std::shared_ptr<Texture<Float>> shadowAlphaTex;
std::string shadowAlphaTexName = params.FindTexture("shadowalpha");
if (shadowAlphaTexName != "") {
if (floatTextures->find(shadowAlphaTexName) != floatTextures->end())
shadowAlphaTex = (*floatTextures)[shadowAlphaTexName];
else
Error(
"Couldn't find float texture \"%s\" for \"shadowalpha\" "
"parameter",
shadowAlphaTexName.c_str());
} else if (params.FindOneFloat("shadowalpha", 1.f) == 0.f)
shadowAlphaTex.reset(new ConstantTexture<Float>(0.f));
return CreateTriangleMesh(o2w, w2o, reverseOrientation, nvi / 3, vi, npi, P,
S, N, uvs, alphaTex, shadowAlphaTex);
}
