switched to a more realistic plastic material that accounts for internal scattering
Wenzel Jakob
parent
2931e0dd37
commit
a16b74eb0f
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@ -5,6 +5,7 @@ plugins += env.SharedLibrary('diffuse', ['diffuse.cpp'])
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plugins += env.SharedLibrary('dielectric', ['dielectric.cpp'])
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plugins += env.SharedLibrary('conductor', ['conductor.cpp'])
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plugins += env.SharedLibrary('plastic', ['plastic.cpp'])
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plugins += env.SharedLibrary('oldplastic', ['oldplastic.cpp'])
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plugins += env.SharedLibrary('roughdiffuse', ['roughdiffuse.cpp'])
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plugins += env.SharedLibrary('roughdielectric', ['roughdielectric.cpp'])
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plugins += env.SharedLibrary('roughconductor', ['roughconductor.cpp'])
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@ -0,0 +1,449 @@
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/*
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This file is part of Mitsuba, a physically based rendering system.
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Copyright (c) 2007-2011 by Wenzel Jakob and others.
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Mitsuba is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License Version 3
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as published by the Free Software Foundation.
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Mitsuba is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program. If not, see <http://www.gnu.org/licenses/>.
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*/
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#include <mitsuba/render/bsdf.h>
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#include <mitsuba/hw/basicshader.h>
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#include "ior.h"
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MTS_NAMESPACE_BEGIN
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/*!\plugin{plastic}{Smooth plastic material}
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* \order{7}
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* \icon{bsdf_plastic}
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* \parameters{
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* \parameter{intIOR}{\Float\Or\String}{Interior index of refraction specified
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* numerically or using a known material name. \default{\texttt{polypropylene} / 1.49}}
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* \parameter{extIOR}{\Float\Or\String}{Exterior index of refraction specified
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* numerically or using a known material name. \default{\texttt{air} / 1.000277}}
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* \parameter{specular\showbreak Reflectance}{\Spectrum\Or\Texture}{Optional
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* factor used to modulate the specular reflection component. Note that for physical
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* realism, this parameter should never be touched. \default{1.0}}
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* \parameter{diffuse\showbreak Reflectance}{\Spectrum\Or\Texture}{Optional
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* factor used to modulate the diffuse reflection component\default{0.5}}
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* }
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*
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* \renderings{
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* \rendering{A rendering with the default parameters}{bsdf_plastic_default}
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* \rendering{A rendering with custom parameters (\lstref{plastic-shiny})}
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* {bsdf_plastic_shiny}
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* }
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*
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* This plugin describes a perfectly smooth plastic-like dielectric material
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* with internal scattering. The model interpolates between ideally specular
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* and ideally diffuse reflection based on the Fresnel reflectance (i.e. it
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* does so in a way that depends on the angle of incidence). Similar to the
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* \pluginref{dielectric} plugin, IOR values can either be specified
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* numerically, or based on a list of known materials (see
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* \tblref{dielectric-iors} for an overview).
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*
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* Since it is very simple and fast, this model is often a better choice
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* than the \pluginref{phong}, \pluginref{ward}, and \pluginref{roughplastic}
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* plugins when rendering very smooth plastic-like materials. \vspace{4mm}
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*
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* \begin{xml}[caption=A shiny material whose diffuse reflectance is
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* specified using sRGB, label=lst:plastic-shiny]
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* <bsdf type="plastic">
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* <srgb name="diffuseReflectance" value="#18455c"/>
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* <float name="intIOR" value="1.9"/>
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* </bsdf>
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* \end{xml}
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*/
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class SmoothPlastic : public BSDF {
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public:
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SmoothPlastic(const Properties &props) : BSDF(props) {
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/* Specifies the internal index of refraction at the interface */
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m_intIOR = lookupIOR(props, "intIOR", "polypropylene");
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/* Specifies the external index of refraction at the interface */
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m_extIOR = lookupIOR(props, "extIOR", "air");
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m_specularReflectance = new ConstantSpectrumTexture(
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props.getSpectrum("specularReflectance", Spectrum(1.0f)));
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m_diffuseReflectance = new ConstantSpectrumTexture(
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props.getSpectrum("diffuseReflectance", Spectrum(0.5f)));
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m_specularSamplingWeight = 0.0f;
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}
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SmoothPlastic(Stream *stream, InstanceManager *manager)
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: BSDF(stream, manager) {
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m_intIOR = stream->readFloat();
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m_extIOR = stream->readFloat();
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m_specularReflectance = static_cast<Texture *>(manager->getInstance(stream));
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m_diffuseReflectance = static_cast<Texture *>(manager->getInstance(stream));
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configure();
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}
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void configure() {
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/* Verify the input parameters and fix them if necessary */
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m_specularReflectance = ensureEnergyConservation(
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m_specularReflectance, "specularReflectance", 1.0f);
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m_diffuseReflectance = ensureEnergyConservation(
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m_diffuseReflectance, "diffuseReflectance", 1.0f);
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/* Compute weights that further steer samples towards
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the specular or diffuse components */
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Float dAvg = m_diffuseReflectance->getAverage().getLuminance(),
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sAvg = m_specularReflectance->getAverage().getLuminance();
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m_specularSamplingWeight = sAvg / (dAvg + sAvg);
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m_usesRayDifferentials =
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m_specularReflectance->usesRayDifferentials() ||
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m_diffuseReflectance->usesRayDifferentials();
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m_components.clear();
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m_components.push_back(EDeltaReflection | EFrontSide
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| (m_specularReflectance->isConstant() ? 0 : ESpatiallyVarying));
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m_components.push_back(EDiffuseReflection | EFrontSide
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| (m_diffuseReflectance->isConstant() ? 0 : ESpatiallyVarying));
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BSDF::configure();
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}
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Spectrum getDiffuseReflectance(const Intersection &its) const {
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return m_diffuseReflectance->getValue(its);
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}
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void serialize(Stream *stream, InstanceManager *manager) const {
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BSDF::serialize(stream, manager);
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stream->writeFloat(m_intIOR);
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stream->writeFloat(m_extIOR);
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manager->serialize(stream, m_specularReflectance.get());
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manager->serialize(stream, m_diffuseReflectance.get());
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}
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void addChild(const std::string &name, ConfigurableObject *child) {
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if (child->getClass()->derivesFrom(MTS_CLASS(Texture))) {
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if (name == "specularReflectance")
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m_specularReflectance = static_cast<Texture *>(child);
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else if (name == "diffuseReflectance")
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m_diffuseReflectance = static_cast<Texture *>(child);
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else
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BSDF::addChild(name, child);
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} else {
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BSDF::addChild(name, child);
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}
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}
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/// Reflection in local coordinates
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inline Vector reflect(const Vector &wi) const {
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return Vector(-wi.x, -wi.y, wi.z);
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}
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Spectrum eval(const BSDFQueryRecord &bRec, EMeasure measure) const {
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bool hasSpecular = (bRec.typeMask & EDeltaReflection)
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&& (bRec.component == -1 || bRec.component == 0);
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bool hasDiffuse = (bRec.typeMask & EDiffuseReflection)
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&& (bRec.component == -1 || bRec.component == 1);
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if (Frame::cosTheta(bRec.wo) <= 0 || Frame::cosTheta(bRec.wi) <= 0)
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return Spectrum(0.0f);
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Float Fr = fresnel(Frame::cosTheta(bRec.wi), m_extIOR, m_intIOR);
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if (measure == EDiscrete && hasSpecular) {
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/* Check if the provided direction pair matches an ideal
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specular reflection; tolerate some roundoff errors */
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bool reflection = std::abs(1 - dot(reflect(bRec.wi), bRec.wo)) < Epsilon;
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if (reflection)
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return m_specularReflectance->getValue(bRec.its) * Fr;
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} else if (measure == ESolidAngle && hasDiffuse) {
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if (hasDiffuse)
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return m_diffuseReflectance->getValue(bRec.its)
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* (INV_PI * Frame::cosTheta(bRec.wo) * (1-Fr));
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}
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return Spectrum(0.0f);
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}
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Float pdf(const BSDFQueryRecord &bRec, EMeasure measure) const {
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bool hasSpecular = (bRec.typeMask & EDeltaReflection)
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&& (bRec.component == -1 || bRec.component == 0);
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bool hasDiffuse = (bRec.typeMask & EDiffuseReflection)
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&& (bRec.component == -1 || bRec.component == 1);
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if (Frame::cosTheta(bRec.wo) <= 0 || Frame::cosTheta(bRec.wi) <= 0)
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return 0.0f;
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Float probSpecular = 1.0f;
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if (hasSpecular && hasDiffuse) {
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Float Fr = fresnel(Frame::cosTheta(bRec.wi), m_extIOR, m_intIOR);
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probSpecular = (Fr*m_specularSamplingWeight) /
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(Fr*m_specularSamplingWeight +
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(1-Fr) * (1-m_specularSamplingWeight));
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}
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if (measure == EDiscrete && hasSpecular) {
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/* Check if the provided direction pair matches an ideal
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specular reflection; tolerate some roundoff errors */
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if (std::abs(1 - dot(reflect(bRec.wi), bRec.wo)) < Epsilon)
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return probSpecular;
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} else if (measure == ESolidAngle && hasDiffuse) {
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return Frame::cosTheta(bRec.wo) * INV_PI *
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(hasSpecular ? (1 - probSpecular) : 1.0f);
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}
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return 0.0f;
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}
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Spectrum sample(BSDFQueryRecord &bRec, const Point2 &sample) const {
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bool hasSpecular = (bRec.typeMask & EDeltaReflection)
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&& (bRec.component == -1 || bRec.component == 0);
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bool hasDiffuse = (bRec.typeMask & EDiffuseReflection)
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&& (bRec.component == -1 || bRec.component == 1);
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if ((!hasDiffuse && !hasSpecular) || Frame::cosTheta(bRec.wi) <= 0)
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return Spectrum(0.0f);
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Float Fr = fresnel(Frame::cosTheta(bRec.wi), m_extIOR, m_intIOR);
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Float probSpecular = (Fr*m_specularSamplingWeight) /
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(Fr*m_specularSamplingWeight +
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(1-Fr) * (1-m_specularSamplingWeight));
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if (hasDiffuse && hasSpecular) {
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/* Importance sample wrt. the Fresnel reflectance */
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if (sample.x <= probSpecular) {
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bRec.sampledComponent = 0;
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bRec.sampledType = EDeltaReflection;
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bRec.wo = reflect(bRec.wi);
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return m_specularReflectance->getValue(bRec.its) *
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(Fr / probSpecular);
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} else {
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bRec.sampledComponent = 1;
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bRec.sampledType = EDiffuseReflection;
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bRec.wo = squareToHemispherePSA(Point2(
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(sample.x - probSpecular) / (1 - probSpecular),
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sample.y
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));
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return m_diffuseReflectance->getValue(bRec.its) *
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((1-Fr) / (1-probSpecular));
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}
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} else if (hasSpecular) {
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bRec.sampledComponent = 0;
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bRec.sampledType = EDeltaReflection;
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bRec.wo = reflect(bRec.wi);
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return m_specularReflectance->getValue(bRec.its) * Fr;
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} else {
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bRec.sampledComponent = 1;
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bRec.sampledType = EDiffuseReflection;
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if (Fr == 1.0f) /* Total internal reflection */
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return Spectrum(0.0f);
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bRec.wo = squareToHemispherePSA(sample);
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return m_diffuseReflectance->getValue(bRec.its) * (1-Fr);
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}
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}
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Spectrum sample(BSDFQueryRecord &bRec, Float &pdf, const Point2 &sample) const {
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bool hasSpecular = (bRec.typeMask & EDeltaReflection)
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&& (bRec.component == -1 || bRec.component == 0);
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bool hasDiffuse = (bRec.typeMask & EDiffuseReflection)
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&& (bRec.component == -1 || bRec.component == 1);
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if ((!hasDiffuse && !hasSpecular) || Frame::cosTheta(bRec.wi) <= 0)
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return Spectrum(0.0f);
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Float Fr = fresnel(Frame::cosTheta(bRec.wi), m_extIOR, m_intIOR);
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Float probSpecular = (Fr*m_specularSamplingWeight) /
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(Fr*m_specularSamplingWeight +
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(1-Fr) * (1-m_specularSamplingWeight));
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if (hasDiffuse && hasSpecular) {
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/* Importance sample wrt. the Fresnel reflectance */
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if (sample.x <= probSpecular) {
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bRec.sampledComponent = 0;
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bRec.sampledType = EDeltaReflection;
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bRec.wo = reflect(bRec.wi);
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pdf = probSpecular;
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return m_specularReflectance->getValue(bRec.its)
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* Fr / probSpecular;
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} else {
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bRec.sampledComponent = 1;
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bRec.sampledType = EDiffuseReflection;
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bRec.wo = squareToHemispherePSA(Point2(
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(sample.x - probSpecular) / (1 - probSpecular),
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sample.y
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));
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pdf = (1-probSpecular) * Frame::cosTheta(bRec.wo) * INV_PI;
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return m_diffuseReflectance->getValue(bRec.its)
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* (1-Fr) / (1-probSpecular);
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}
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} else if (hasSpecular) {
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bRec.sampledComponent = 0;
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bRec.sampledType = EDeltaReflection;
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bRec.wo = reflect(bRec.wi);
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pdf = 1;
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return m_specularReflectance->getValue(bRec.its) * Fr;
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} else {
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bRec.sampledComponent = 1;
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bRec.sampledType = EDiffuseReflection;
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if (Fr == 1.0f) /* Total internal reflection */
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return Spectrum(0.0f);
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bRec.wo = squareToHemispherePSA(sample);
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pdf = Frame::cosTheta(bRec.wo) * INV_PI;
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return m_diffuseReflectance->getValue(bRec.its) * (1-Fr);
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}
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}
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Shader *createShader(Renderer *renderer) const;
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std::string toString() const {
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std::ostringstream oss;
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oss << "SmoothPlastic[" << endl
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<< " name = \"" << getName() << "\"," << endl
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<< " specularReflectance = " << indent(m_specularReflectance->toString()) << "," << endl
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<< " diffuseReflectance = " << indent(m_diffuseReflectance->toString()) << "," << endl
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<< " specularSamplingWeight = " << m_specularSamplingWeight << "," << endl
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<< " diffuseSamplingWeight = " << (1-m_specularSamplingWeight) << "," << endl
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<< " intIOR = " << m_intIOR << "," << endl
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<< " extIOR = " << m_extIOR << endl
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<< "]";
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return oss.str();
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}
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MTS_DECLARE_CLASS()
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private:
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Float m_intIOR, m_extIOR;
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ref<Texture> m_diffuseReflectance;
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ref<Texture> m_specularReflectance;
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Float m_specularSamplingWeight;
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};
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/**
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* Smooth plastic shader -- it is really hopeless to visualize
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* this material in the VPL renderer, so let's try to do at least
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* something that suggests the presence of a specularly-reflecting
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* dielectric coating.
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*/
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class SmoothPlasticShader : public Shader {
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public:
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SmoothPlasticShader(Renderer *renderer, const Texture *specularReflectance,
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const Texture *diffuseReflectance, Float extIOR,
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Float intIOR) : Shader(renderer, EBSDFShader),
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m_specularReflectance(specularReflectance),
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m_diffuseReflectance(diffuseReflectance),
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m_extIOR(extIOR), m_intIOR(intIOR) {
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m_specularReflectanceShader = renderer->registerShaderForResource(m_specularReflectance.get());
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m_diffuseReflectanceShader = renderer->registerShaderForResource(m_diffuseReflectance.get());
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m_alpha = 0.4f;
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m_R0 = fresnel(1.0f, m_extIOR, m_intIOR);
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}
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bool isComplete() const {
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return m_specularReflectanceShader.get() != NULL &&
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m_diffuseReflectanceShader.get() != NULL;
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}
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void putDependencies(std::vector<Shader *> &deps) {
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deps.push_back(m_specularReflectanceShader.get());
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deps.push_back(m_diffuseReflectanceShader.get());
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}
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void cleanup(Renderer *renderer) {
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renderer->unregisterShaderForResource(m_specularReflectance.get());
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renderer->unregisterShaderForResource(m_diffuseReflectance.get());
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}
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void resolve(const GPUProgram *program, const std::string &evalName, std::vector<int> ¶meterIDs) const {
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parameterIDs.push_back(program->getParameterID(evalName + "_alpha", false));
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parameterIDs.push_back(program->getParameterID(evalName + "_R0", false));
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}
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void bind(GPUProgram *program, const std::vector<int> ¶meterIDs, int &textureUnitOffset) const {
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program->setParameter(parameterIDs[0], m_alpha);
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program->setParameter(parameterIDs[1], m_R0);
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}
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void generateCode(std::ostringstream &oss,
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const std::string &evalName,
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const std::vector<std::string> &depNames) const {
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oss << "uniform float " << evalName << "_alpha;" << endl
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<< "uniform float " << evalName << "_R0;" << endl
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<< endl
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<< "float " << evalName << "_D(vec3 m) {" << endl
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<< " float ct = cosTheta(m);" << endl
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<< " if (cosTheta(m) <= 0.0)" << endl
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<< " return 0.0;" << endl
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<< " float ex = tanTheta(m) / " << evalName << "_alpha;" << endl
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<< " return exp(-(ex*ex)) / (pi * " << evalName << "_alpha" << endl
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<< " * " << evalName << "_alpha * pow(cosTheta(m), 4.0));" << endl
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<< "}" << endl
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<< endl
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<< "float " << evalName << "_G(vec3 m, vec3 wi, vec3 wo) {" << endl
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<< " if ((dot(wi, m) * cosTheta(wi)) <= 0 || " << endl
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<< " (dot(wo, m) * cosTheta(wo)) <= 0)" << endl
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<< " return 0.0;" << endl
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<< " float nDotM = cosTheta(m);" << endl
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<< " return min(1.0, min(" << endl
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<< " abs(2 * nDotM * cosTheta(wo) / dot(wo, m))," << endl
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<< " abs(2 * nDotM * cosTheta(wi) / dot(wi, m))));" << endl
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<< "}" << endl
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<< endl
|
||||
<< "float " << evalName << "_schlick(float ct) {" << endl
|
||||
<< " float ctSqr = ct*ct, ct5 = ctSqr*ctSqr*ct;" << endl
|
||||
<< " return " << evalName << "_R0 + (1.0 - " << evalName << "_R0) * ct5;" << endl
|
||||
<< "}" << endl
|
||||
<< endl
|
||||
<< "vec3 " << evalName << "(vec2 uv, vec3 wi, vec3 wo) {" << endl
|
||||
<< " if (cosTheta(wi) <= 0 || cosTheta(wo) <= 0)" << endl
|
||||
<< " return vec3(0.0);" << endl
|
||||
<< " vec3 H = normalize(wi + wo);" << endl
|
||||
<< " vec3 specRef = " << depNames[0] << "(uv);" << endl
|
||||
<< " vec3 diffuseRef = " << depNames[1] << "(uv);" << endl
|
||||
<< " float D = " << evalName << "_D(H)" << ";" << endl
|
||||
<< " float G = " << evalName << "_G(H, wi, wo);" << endl
|
||||
<< " float F = " << evalName << "_schlick(1-dot(wi, H));" << endl
|
||||
<< " return specRef * (F * D * G / (4*cosTheta(wi))) + " << endl
|
||||
<< " diffuseRef * ((1-F) * cosTheta(wo) * 0.31831);" << endl
|
||||
<< "}" << endl
|
||||
<< endl
|
||||
<< "vec3 " << evalName << "_diffuse(vec2 uv, vec3 wi, vec3 wo) {" << endl
|
||||
<< " vec3 diffuseRef = " << depNames[1] << "(uv);" << endl
|
||||
<< " return diffuseRef * 0.31831 * cosTheta(wo);"<< endl
|
||||
<< "}" << endl;
|
||||
}
|
||||
MTS_DECLARE_CLASS()
|
||||
private:
|
||||
ref<const Texture> m_specularReflectance;
|
||||
ref<const Texture> m_diffuseReflectance;
|
||||
ref<Shader> m_specularReflectanceShader;
|
||||
ref<Shader> m_diffuseReflectanceShader;
|
||||
Float m_alpha, m_extIOR, m_intIOR, m_R0;
|
||||
};
|
||||
|
||||
Shader *SmoothPlastic::createShader(Renderer *renderer) const {
|
||||
return new SmoothPlasticShader(renderer,
|
||||
m_specularReflectance.get(), m_diffuseReflectance.get(), m_extIOR, m_intIOR);
|
||||
}
|
||||
|
||||
MTS_IMPLEMENT_CLASS(SmoothPlasticShader, false, Shader)
|
||||
|
||||
MTS_IMPLEMENT_CLASS_S(SmoothPlastic, false, BSDF)
|
||||
MTS_EXPORT_PLUGIN(SmoothPlastic, "Smooth plastic BRDF");
|
||||
MTS_NAMESPACE_END
|
||||
|
|
@ -30,6 +30,14 @@ MTS_NAMESPACE_BEGIN
|
|||
* numerically or using a known material name. \default{\texttt{polypropylene} / 1.49}}
|
||||
* \parameter{extIOR}{\Float\Or\String}{Exterior index of refraction specified
|
||||
* numerically or using a known material name. \default{\texttt{air} / 1.000277}}
|
||||
* \parameter{preserveColors}{\Boolean}{
|
||||
* By default, this implementation accounts for light that undergoes any number
|
||||
* of internal reflections from the dielectric material boundary before exiting, which
|
||||
* potentially causes the diffuse component to shift towards more saturated colors.
|
||||
* While realistic, this behavior might not always be desirable. In that case, set
|
||||
* this parameter to \code{true}.
|
||||
* \default{\code{false}}
|
||||
* }
|
||||
* \parameter{specular\showbreak Reflectance}{\Spectrum\Or\Texture}{Optional
|
||||
* factor used to modulate the specular reflection component. Note that for physical
|
||||
* realism, this parameter should never be touched. \default{1.0}}
|
||||
|
|
@ -51,9 +59,9 @@ MTS_NAMESPACE_BEGIN
|
|||
* numerically, or based on a list of known materials (see
|
||||
* \tblref{dielectric-iors} for an overview).
|
||||
*
|
||||
* Since it is very simple and fast, this model is often a better choice
|
||||
* Since it is simple and fast, this model is often a better choice
|
||||
* than the \pluginref{phong}, \pluginref{ward}, and \pluginref{roughplastic}
|
||||
* plugins when rendering very smooth plastic-like materials. \vspace{4mm}
|
||||
* plugins when rendering smooth plastic-like materials. \vspace{4mm}
|
||||
*
|
||||
* \begin{xml}[caption=A shiny material whose diffuse reflectance is
|
||||
* specified using sRGB, label=lst:plastic-shiny]
|
||||
|
|
@ -76,6 +84,9 @@ public:
|
|||
props.getSpectrum("specularReflectance", Spectrum(1.0f)));
|
||||
m_diffuseReflectance = new ConstantSpectrumTexture(
|
||||
props.getSpectrum("diffuseReflectance", Spectrum(0.5f)));
|
||||
|
||||
m_preserveColors = props.getBoolean("preserveColors", false);
|
||||
|
||||
m_specularSamplingWeight = 0.0f;
|
||||
}
|
||||
|
||||
|
|
@ -83,6 +94,7 @@ public:
|
|||
: BSDF(stream, manager) {
|
||||
m_intIOR = stream->readFloat();
|
||||
m_extIOR = stream->readFloat();
|
||||
m_preserveColors = stream->readBool();
|
||||
m_specularReflectance = static_cast<Texture *>(manager->getInstance(stream));
|
||||
m_diffuseReflectance = static_cast<Texture *>(manager->getInstance(stream));
|
||||
configure();
|
||||
|
|
@ -95,10 +107,14 @@ public:
|
|||
m_diffuseReflectance = ensureEnergyConservation(
|
||||
m_diffuseReflectance, "diffuseReflectance", 1.0f);
|
||||
|
||||
/* Numerically approximate the diffuse Fresnel reflectance */
|
||||
m_fdr = fresnelDiffuseReflectance(m_extIOR / m_intIOR, false);
|
||||
|
||||
/* Compute weights that further steer samples towards
|
||||
the specular or diffuse components */
|
||||
Float dAvg = m_diffuseReflectance->getAverage().getLuminance(),
|
||||
sAvg = m_specularReflectance->getAverage().getLuminance();
|
||||
|
||||
m_specularSamplingWeight = sAvg / (dAvg + sAvg);
|
||||
|
||||
m_usesRayDifferentials =
|
||||
|
|
@ -124,6 +140,7 @@ public:
|
|||
|
||||
stream->writeFloat(m_intIOR);
|
||||
stream->writeFloat(m_extIOR);
|
||||
stream->writeBool(m_preserveColors);
|
||||
manager->serialize(stream, m_specularReflectance.get());
|
||||
manager->serialize(stream, m_diffuseReflectance.get());
|
||||
}
|
||||
|
|
@ -164,9 +181,16 @@ public:
|
|||
if (reflection)
|
||||
return m_specularReflectance->getValue(bRec.its) * Fr;
|
||||
} else if (measure == ESolidAngle && hasDiffuse) {
|
||||
if (hasDiffuse)
|
||||
return m_diffuseReflectance->getValue(bRec.its)
|
||||
* (INV_PI * Frame::cosTheta(bRec.wo) * (1-Fr));
|
||||
Float Fr2 = fresnel(Frame::cosTheta(bRec.wo), m_extIOR, m_intIOR);
|
||||
|
||||
if (hasDiffuse) {
|
||||
Spectrum diff = m_diffuseReflectance->getValue(bRec.its);
|
||||
if (m_preserveColors)
|
||||
diff /= 1 - m_fdr;
|
||||
else
|
||||
diff /= Spectrum(1) - m_fdr*diff;
|
||||
return diff * (INV_PI * Frame::cosTheta(bRec.wo) * (1-Fr) * (1-Fr2));
|
||||
}
|
||||
}
|
||||
|
||||
return Spectrum(0.0f);
|
||||
|
|
@ -232,9 +256,15 @@ public:
|
|||
(sample.x - probSpecular) / (1 - probSpecular),
|
||||
sample.y
|
||||
));
|
||||
Float Fr2 = fresnel(Frame::cosTheta(bRec.wo), m_extIOR, m_intIOR);
|
||||
|
||||
return m_diffuseReflectance->getValue(bRec.its) *
|
||||
((1-Fr) / (1-probSpecular));
|
||||
Spectrum diff = m_diffuseReflectance->getValue(bRec.its);
|
||||
if (m_preserveColors)
|
||||
diff /= 1 - m_fdr;
|
||||
else
|
||||
diff /= Spectrum(1) - m_fdr*diff;
|
||||
|
||||
return diff * ((1-Fr) * (1-Fr2) / (1-probSpecular));
|
||||
}
|
||||
} else if (hasSpecular) {
|
||||
bRec.sampledComponent = 0;
|
||||
|
|
@ -242,15 +272,19 @@ public:
|
|||
bRec.wo = reflect(bRec.wi);
|
||||
return m_specularReflectance->getValue(bRec.its) * Fr;
|
||||
} else {
|
||||
bRec.wo = squareToHemispherePSA(sample);
|
||||
Float Fr2 = fresnel(Frame::cosTheta(bRec.wo), m_extIOR, m_intIOR);
|
||||
bRec.sampledComponent = 1;
|
||||
bRec.sampledType = EDiffuseReflection;
|
||||
|
||||
if (Fr == 1.0f) /* Total internal reflection */
|
||||
return Spectrum(0.0f);
|
||||
Spectrum diff = m_diffuseReflectance->getValue(bRec.its);
|
||||
if (m_preserveColors)
|
||||
diff /= 1 - m_fdr;
|
||||
else
|
||||
diff /= Spectrum(1) - m_fdr*diff;
|
||||
|
||||
bRec.wo = squareToHemispherePSA(sample);
|
||||
|
||||
return m_diffuseReflectance->getValue(bRec.its) * (1-Fr);
|
||||
return diff * (1-Fr) * (1-Fr2);
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -285,10 +319,17 @@ public:
|
|||
(sample.x - probSpecular) / (1 - probSpecular),
|
||||
sample.y
|
||||
));
|
||||
Float Fr2 = fresnel(Frame::cosTheta(bRec.wo), m_extIOR, m_intIOR);
|
||||
|
||||
Spectrum diff = m_diffuseReflectance->getValue(bRec.its);
|
||||
if (m_preserveColors)
|
||||
diff /= 1 - m_fdr;
|
||||
else
|
||||
diff /= Spectrum(1) - m_fdr*diff;
|
||||
|
||||
pdf = (1-probSpecular) * Frame::cosTheta(bRec.wo) * INV_PI;
|
||||
|
||||
return m_diffuseReflectance->getValue(bRec.its)
|
||||
* (1-Fr) / (1-probSpecular);
|
||||
return diff * ((1-Fr) * (1-Fr2) / (1-probSpecular));
|
||||
}
|
||||
} else if (hasSpecular) {
|
||||
bRec.sampledComponent = 0;
|
||||
|
|
@ -299,6 +340,7 @@ public:
|
|||
} else {
|
||||
bRec.sampledComponent = 1;
|
||||
bRec.sampledType = EDiffuseReflection;
|
||||
Float Fr2 = fresnel(Frame::cosTheta(bRec.wo), m_extIOR, m_intIOR);
|
||||
|
||||
if (Fr == 1.0f) /* Total internal reflection */
|
||||
return Spectrum(0.0f);
|
||||
|
|
@ -307,7 +349,13 @@ public:
|
|||
|
||||
pdf = Frame::cosTheta(bRec.wo) * INV_PI;
|
||||
|
||||
return m_diffuseReflectance->getValue(bRec.its) * (1-Fr);
|
||||
Spectrum diff = m_diffuseReflectance->getValue(bRec.its);
|
||||
if (m_preserveColors)
|
||||
diff /= 1 - m_fdr;
|
||||
else
|
||||
diff /= Spectrum(1) - m_fdr*diff;
|
||||
|
||||
return diff * (1-Fr) * (1-Fr2);
|
||||
}
|
||||
}
|
||||
|
||||
|
|
@ -321,18 +369,21 @@ public:
|
|||
<< " diffuseReflectance = " << indent(m_diffuseReflectance->toString()) << "," << endl
|
||||
<< " specularSamplingWeight = " << m_specularSamplingWeight << "," << endl
|
||||
<< " diffuseSamplingWeight = " << (1-m_specularSamplingWeight) << "," << endl
|
||||
<< " preserveColors = " << m_preserveColors << "," << endl
|
||||
<< " intIOR = " << m_intIOR << "," << endl
|
||||
<< " extIOR = " << m_extIOR << endl
|
||||
<< " extIOR = " << m_extIOR << "," << endl
|
||||
<< " fdr = " << m_fdr << endl
|
||||
<< "]";
|
||||
return oss.str();
|
||||
}
|
||||
|
||||
MTS_DECLARE_CLASS()
|
||||
private:
|
||||
Float m_intIOR, m_extIOR;
|
||||
Float m_intIOR, m_extIOR, m_fdr;
|
||||
ref<Texture> m_diffuseReflectance;
|
||||
ref<Texture> m_specularReflectance;
|
||||
Float m_specularSamplingWeight;
|
||||
bool m_preserveColors;
|
||||
};
|
||||
|
||||
/**
|
||||
|
|
|
|||
Loading…
Reference in New Issue