sphere.cpp

/*
    This file is part of Nori, a simple educational ray tracer
 
    Copyright (c) 2015 by Romain Prévost
 
    Nori is free software; you can redistribute it and/or modify
    it under the terms of the GNU General Public License Version 3
    as published by the Free Software Foundation.
 
    Nori is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    GNU General Public License for more details.
 
    You should have received a copy of the GNU General Public License
    along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
 
#include <nori/shape.h>
#include <nori/bsdf.h>
#include <nori/emitter.h>
#include <nori/warp.h>
 
NORI_NAMESPACE_BEGIN
 
class Sphere : public Shape {
public:
    Sphere(const PropertyList & propList) {
        m_position = propList.getPoint3("center", Point3f());
        m_radius = propList.getFloat("radius", 1.f);
 
        m_bbox.expandBy(m_position - Vector3f(m_radius));
        m_bbox.expandBy(m_position + Vector3f(m_radius));
    }
 
    virtual BoundingBox3f getBoundingBox(uint32_t index) const override { return m_bbox; }
 
    virtual Point3f getCentroid(uint32_t index) const override { return m_position; }
 
    virtual bool rayIntersect(uint32_t index, const Ray3f &ray, float &u, float &v, float &t) const override {
 
    /* to be implemented */
        return false;
 
    }
 
    virtual void setHitInformation(uint32_t index, const Ray3f &ray, Intersection & its) const override {
        /* to be implemented */
    }
 
    virtual void sampleSurface(ShapeQueryRecord & sRec, const Point2f & sample) const override {
        Vector3f q = Warp::squareToUniformSphere(sample);
        sRec.p = m_position + m_radius * q;
        sRec.n = q;
        sRec.pdf = std::pow(1.f/m_radius,2) * Warp::squareToUniformSpherePdf(Vector3f(0.0f,0.0f,1.0f));
    }
    virtual float pdfSurface(const ShapeQueryRecord & sRec) const override {
        return std::pow(1.f/m_radius,2) * Warp::squareToUniformSpherePdf(Vector3f(0.0f,0.0f,1.0f));
    }
 
 
    virtual std::string toString() const override {
        return tfm::format(
                "Sphere[\n"
                "  center = %s,\n"
                "  radius = %f,\n"
                "  bsdf = %s,\n"
                "  emitter = %s\n"
                "]",
                m_position.toString(),
                m_radius,
                m_bsdf ? indent(m_bsdf->toString()) : std::string("null"),
                m_emitter ? indent(m_emitter->toString()) : std::string("null"));
    }
 
protected:
    Point3f m_position;
    float m_radius;
};
 
NORI_REGISTER_CLASS(Sphere, "sphere");
NORI_NAMESPACE_END