C++ ParamSet::FindFloat方法代码示例

std::shared_ptr<Medium> MakeMedium(const std::string &name,
                                   const ParamSet &paramSet,
                                   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 &params) {
    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);
//.........这里部分代码省略.........

std::vector<std::shared_ptr<Shape>> CreateTriangleMeshShape(
    const Transform *o2w, const Transform *w2o, bool reverseOrientation,
    const ParamSet &params,
    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 != "") {
//.........这里部分代码省略.........