fireball/lib/renderers/shaders/ShaderChunk/envmap_physical_pars_fragment.glsl
2018-12-25 17:29:22 +03:30

134 lines
3.9 KiB
GLSL

#if defined( USE_ENVMAP ) && defined( PHYSICAL )
vec3 getLightProbeIndirectIrradiance( /*const in SpecularLightProbe specularLightProbe,*/ const in GeometricContext geometry, const in int maxMIPLevel ) {
vec3 worldNormal = inverseTransformDirection( geometry.normal, viewMatrix );
#ifdef ENVMAP_TYPE_CUBE
vec3 queryVec = vec3( flipEnvMap * worldNormal.x, worldNormal.yz );
// TODO: replace with properly filtered cubemaps and access the irradiance LOD level, be it the last LOD level
// of a specular cubemap, or just the default level of a specially created irradiance cubemap.
#ifdef TEXTURE_LOD_EXT
vec4 envMapColor = textureCubeLodEXT( envMap, queryVec, float( maxMIPLevel ) );
#else
// force the bias high to get the last LOD level as it is the most blurred.
vec4 envMapColor = textureCube( envMap, queryVec, float( maxMIPLevel ) );
#endif
envMapColor.rgb = envMapTexelToLinear( envMapColor ).rgb;
#elif defined( ENVMAP_TYPE_CUBE_UV )
vec3 queryVec = vec3( flipEnvMap * worldNormal.x, worldNormal.yz );
vec4 envMapColor = textureCubeUV( envMap, queryVec, 1.0 );
#else
vec4 envMapColor = vec4( 0.0 );
#endif
return PI * envMapColor.rgb * envMapIntensity;
}
// taken from here: http://casual-effects.blogspot.ca/2011/08/plausible-environment-lighting-in-two.html
float getSpecularMIPLevel( const in float blinnShininessExponent, const in int maxMIPLevel ) {
//float envMapWidth = pow( 2.0, maxMIPLevelScalar );
//float desiredMIPLevel = log2( envMapWidth * sqrt( 3.0 ) ) - 0.5 * log2( pow2( blinnShininessExponent ) + 1.0 );
float maxMIPLevelScalar = float( maxMIPLevel );
float desiredMIPLevel = maxMIPLevelScalar + 0.79248 - 0.5 * log2( pow2( blinnShininessExponent ) + 1.0 );
// clamp to allowable LOD ranges.
return clamp( desiredMIPLevel, 0.0, maxMIPLevelScalar );
}
vec3 getLightProbeIndirectRadiance( /*const in SpecularLightProbe specularLightProbe,*/ const in GeometricContext geometry, const in float blinnShininessExponent, const in int maxMIPLevel ) {
#ifdef ENVMAP_MODE_REFLECTION
vec3 reflectVec = reflect( -geometry.viewDir, geometry.normal );
#else
vec3 reflectVec = refract( -geometry.viewDir, geometry.normal, refractionRatio );
#endif
reflectVec = inverseTransformDirection( reflectVec, viewMatrix );
float specularMIPLevel = getSpecularMIPLevel( blinnShininessExponent, maxMIPLevel );
#ifdef ENVMAP_TYPE_CUBE
vec3 queryReflectVec = vec3( flipEnvMap * reflectVec.x, reflectVec.yz );
#ifdef TEXTURE_LOD_EXT
vec4 envMapColor = textureCubeLodEXT( envMap, queryReflectVec, specularMIPLevel );
#else
vec4 envMapColor = textureCube( envMap, queryReflectVec, specularMIPLevel );
#endif
envMapColor.rgb = envMapTexelToLinear( envMapColor ).rgb;
#elif defined( ENVMAP_TYPE_CUBE_UV )
vec3 queryReflectVec = vec3( flipEnvMap * reflectVec.x, reflectVec.yz );
vec4 envMapColor = textureCubeUV( envMap, queryReflectVec, BlinnExponentToGGXRoughness(blinnShininessExponent ));
#elif defined( ENVMAP_TYPE_EQUIREC )
vec2 sampleUV;
sampleUV.y = asin( clamp( reflectVec.y, - 1.0, 1.0 ) ) * RECIPROCAL_PI + 0.5;
sampleUV.x = atan( reflectVec.z, reflectVec.x ) * RECIPROCAL_PI2 + 0.5;
#ifdef TEXTURE_LOD_EXT
vec4 envMapColor = texture2DLodEXT( envMap, sampleUV, specularMIPLevel );
#else
vec4 envMapColor = texture2D( envMap, sampleUV, specularMIPLevel );
#endif
envMapColor.rgb = envMapTexelToLinear( envMapColor ).rgb;
#elif defined( ENVMAP_TYPE_SPHERE )
vec3 reflectView = normalize( ( viewMatrix * vec4( reflectVec, 0.0 ) ).xyz + vec3( 0.0,0.0,1.0 ) );
#ifdef TEXTURE_LOD_EXT
vec4 envMapColor = texture2DLodEXT( envMap, reflectView.xy * 0.5 + 0.5, specularMIPLevel );
#else
vec4 envMapColor = texture2D( envMap, reflectView.xy * 0.5 + 0.5, specularMIPLevel );
#endif
envMapColor.rgb = envMapTexelToLinear( envMapColor ).rgb;
#endif
return envMapColor.rgb * envMapIntensity;
}
#endif