std::shared_ptr<Medium> MakeMedium(const std::string &name, const ParamSet ¶mSet, const Transform &medium2world) { Float sig_a_rgb[3] = {.0011f, .0024f, .014f}, sig_s_rgb[3] = {2.55f, 3.21f, 3.77f}; Spectrum sig_a = Spectrum::FromRGB(sig_a_rgb), sig_s = Spectrum::FromRGB(sig_s_rgb); std::string preset = paramSet.FindOneString("preset", ""); bool found = GetMediumScatteringProperties(preset, &sig_a, &sig_s); if (preset != "" && !found) Warning("Material preset \"%s\" not found. Using defaults.", preset.c_str()); Float scale = paramSet.FindOneFloat("scale", 1.f); Float g = paramSet.FindOneFloat("g", 0.0f); sig_a = paramSet.FindOneSpectrum("sigma_a", sig_a) * scale; sig_s = paramSet.FindOneSpectrum("sigma_s", sig_s) * scale; Medium *m = NULL; if (name == "homogeneous") { m = new HomogeneousMedium(sig_a, sig_s, g); } else if (name == "heterogeneous") { int nitems; const Float *data = paramSet.FindFloat("density", &nitems); if (!data) { Error("No \"density\" values provided for heterogeneous medium?"); return NULL; } int nx = paramSet.FindOneInt("nx", 1); int ny = paramSet.FindOneInt("ny", 1); int nz = paramSet.FindOneInt("nz", 1); Point3f p0 = paramSet.FindOnePoint3f("p0", Point3f(0.f, 0.f, 0.f)); Point3f p1 = paramSet.FindOnePoint3f("p1", Point3f(1.f, 1.f, 1.f)); if (nitems != nx * ny * nz) { Error( "GridDensityMedium has %d density values; expected nx*ny*nz = " "%d", nitems, nx * ny * nz); return NULL; } Transform data2Medium = Translate(Vector3f(p0)) * Scale(p1.x - p0.x, p1.y - p0.y, p1.z - p0.z); m = new GridDensityMedium(sig_a, sig_s, g, nx, ny, nz, medium2world * data2Medium, data); } else Warning("Medium \"%s\" unknown.", name.c_str()); paramSet.ReportUnused(); return std::shared_ptr<Medium>(m); }
std::vector<std::shared_ptr<Shape>> CreateNURBS(const Transform *o2w, const Transform *w2o, bool reverseOrientation, const ParamSet ¶ms) { int nu = params.FindOneInt("nu", -1); if (nu == -1) { Error("Must provide number of control points \"nu\" with NURBS shape."); return std::vector<std::shared_ptr<Shape>>(); } int uorder = params.FindOneInt("uorder", -1); if (uorder == -1) { Error("Must provide u order \"uorder\" with NURBS shape."); return std::vector<std::shared_ptr<Shape>>(); } int nuknots, nvknots; const Float *uknots = params.FindFloat("uknots", &nuknots); if (uknots == nullptr) { Error("Must provide u knot vector \"uknots\" with NURBS shape."); return std::vector<std::shared_ptr<Shape>>(); } if (nuknots != nu + uorder) { Error( "Number of knots in u knot vector %d doesn't match sum of " "number of u control points %d and u order %d.", nuknots, nu, uorder); return std::vector<std::shared_ptr<Shape>>(); } Float u0 = params.FindOneFloat("u0", uknots[uorder - 1]); Float u1 = params.FindOneFloat("u1", uknots[nu]); int nv = params.FindOneInt("nv", -1); if (nv == -1) { Error("Must provide number of control points \"nv\" with NURBS shape."); return std::vector<std::shared_ptr<Shape>>(); } int vorder = params.FindOneInt("vorder", -1); if (vorder == -1) { Error("Must provide v order \"vorder\" with NURBS shape."); return std::vector<std::shared_ptr<Shape>>(); } const Float *vknots = params.FindFloat("vknots", &nvknots); if (vknots == nullptr) { Error("Must provide v knot vector \"vknots\" with NURBS shape."); return std::vector<std::shared_ptr<Shape>>(); } if (nvknots != nv + vorder) { Error( "Number of knots in v knot vector %d doesn't match sum of " "number of v control points %d and v order %d.", nvknots, nv, vorder); return std::vector<std::shared_ptr<Shape>>(); } Float v0 = params.FindOneFloat("v0", vknots[vorder - 1]); Float v1 = params.FindOneFloat("v1", vknots[nv]); bool isHomogeneous = false; int npts; const Float *P = (const Float *)params.FindPoint3f("P", &npts); if (!P) { P = params.FindFloat("Pw", &npts); if (!P) { Error( "Must provide control points via \"P\" or \"Pw\" parameter to " "NURBS shape."); return std::vector<std::shared_ptr<Shape>>(); } if ((npts % 4) != 0) { Error( "Number of \"Pw\" control points provided to NURBS shape must " "be " "multiple of four"); return std::vector<std::shared_ptr<Shape>>(); } npts /= 4; isHomogeneous = true; } if (npts != nu * nv) { Error("NURBS shape was expecting %dx%d=%d control points, was given %d", nu, nv, nu * nv, npts); return std::vector<std::shared_ptr<Shape>>(); } // Compute NURBS dicing rates int diceu = 30, dicev = 30; std::unique_ptr<Float[]> ueval(new Float[diceu]); std::unique_ptr<Float[]> veval(new Float[dicev]); std::unique_ptr<Point3f[]> evalPs(new Point3f[diceu * dicev]); std::unique_ptr<Normal3f[]> evalNs(new Normal3f[diceu * dicev]); int i; for (i = 0; i < diceu; ++i) ueval[i] = Lerp((float)i / (float)(diceu - 1), u0, u1); for (i = 0; i < dicev; ++i) veval[i] = Lerp((float)i / (float)(dicev - 1), v0, v1); // Evaluate NURBS over grid of points memset(evalPs.get(), 0, diceu * dicev * sizeof(Point3f)); memset(evalNs.get(), 0, diceu * dicev * sizeof(Point3f)); std::unique_ptr<Point2f[]> uvs(new Point2f[diceu * dicev]); // Turn NURBS into triangles std::unique_ptr<Homogeneous3[]> Pw(new Homogeneous3[nu * nv]); if (isHomogeneous) { for (int i = 0; i < nu * nv; ++i) { Pw[i].x = P[4 * i]; Pw[i].y = P[4 * i + 1]; Pw[i].z = P[4 * i + 2]; Pw[i].w = P[4 * i + 3]; } } else { for (int i = 0; i < nu * nv; ++i) { Pw[i].x = P[3 * i]; Pw[i].y = P[3 * i + 1]; Pw[i].z = P[3 * i + 2]; Pw[i].w = 1.; } } for (int v = 0; v < dicev; ++v) { for (int u = 0; u < diceu; ++u) { uvs[(v * diceu + u)].x = ueval[u]; uvs[(v * diceu + u)].y = veval[v]; Vector3f dpdu, dpdv; Point3f pt = NURBSEvaluateSurface(uorder, uknots, nu, ueval[u], vorder, vknots, nv, veval[v], Pw.get(), &dpdu, &dpdv); evalPs[v * diceu + u].x = pt.x; evalPs[v * diceu + u].y = pt.y; evalPs[v * diceu + u].z = pt.z; evalNs[v * diceu + u] = Normal3f(Normalize(Cross(dpdu, dpdv))); } } // Generate points-polygons mesh int nTris = 2 * (diceu - 1) * (dicev - 1); std::unique_ptr<int[]> vertices(new int[3 * nTris]); int *vertp = vertices.get(); // Compute the vertex offset numbers for the triangles for (int v = 0; v < dicev - 1; ++v) { for (int u = 0; u < diceu - 1; ++u) { #define VN(u, v) ((v)*diceu + (u)) *vertp++ = VN(u, v); *vertp++ = VN(u + 1, v); *vertp++ = VN(u + 1, v + 1); *vertp++ = VN(u, v); *vertp++ = VN(u + 1, v + 1); *vertp++ = VN(u, v + 1); #undef VN } } int nVerts = diceu * dicev; return CreateTriangleMesh(o2w, w2o, reverseOrientation, nTris, vertices.get(), nVerts, evalPs.get(), nullptr, evalNs.get(), uvs.get(), nullptr); }
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); }