cubeUvReflectionFragment top-level property
String
cubeUvReflectionFragment
getter/setter pair
Implementation
String cubeUvReflectionFragment = """
#ifdef ENVMAP_TYPE_CUBE_UV
#define cubeUV_minMipLevel 4.0
#define cubeUV_minTileSize 16.0
// These shader functions convert between the UV coordinates of a single face of
// a cubemap, the 0-5 integer index of a cube face, and the direction vector for
// sampling a textureCube (not generally normalized ).
float getFace( vec3 direction ) {
vec3 absDirection = abs( direction );
float face = - 1.0;
if ( absDirection.x > absDirection.z ) {
if ( absDirection.x > absDirection.y )
face = direction.x > 0.0 ? 0.0 : 3.0;
else
face = direction.y > 0.0 ? 1.0 : 4.0;
} else {
if ( absDirection.z > absDirection.y )
face = direction.z > 0.0 ? 2.0 : 5.0;
else
face = direction.y > 0.0 ? 1.0 : 4.0;
}
return face;
}
// RH coordinate system; PMREM face-indexing convention
vec2 getUV( vec3 direction, float face ) {
vec2 uv;
if ( face == 0.0 ) {
uv = vec2( direction.z, direction.y ) / abs( direction.x ); // pos x
} else if ( face == 1.0 ) {
uv = vec2( - direction.x, - direction.z ) / abs( direction.y ); // pos y
} else if ( face == 2.0 ) {
uv = vec2( - direction.x, direction.y ) / abs( direction.z ); // pos z
} else if ( face == 3.0 ) {
uv = vec2( - direction.z, direction.y ) / abs( direction.x ); // neg x
} else if ( face == 4.0 ) {
uv = vec2( - direction.x, direction.z ) / abs( direction.y ); // neg y
} else {
uv = vec2( direction.x, direction.y ) / abs( direction.z ); // neg z
}
return 0.5 * ( uv + 1.0 );
}
vec3 bilinearCubeUV( sampler2D envMap, vec3 direction, float mipInt ) {
float face = getFace( direction );
float filterInt = max( cubeUV_minMipLevel - mipInt, 0.0 );
mipInt = max( mipInt, cubeUV_minMipLevel );
float faceSize = exp2( mipInt );
vec2 uv = getUV( direction, face ) * ( faceSize - 2.0 ) + 1.0;
if ( face > 2.0 ) {
uv.y += faceSize;
face -= 3.0;
}
uv.x += face * faceSize;
uv.x += filterInt * 3.0 * cubeUV_minTileSize;
uv.y += 4.0 * ( exp2( CUBEUV_MAX_MIP ) - faceSize );
uv.x *= CUBEUV_TEXEL_WIDTH;
uv.y *= CUBEUV_TEXEL_HEIGHT;
#ifdef texture2DGradEXT
return texture2DGradEXT( envMap, uv, vec2( 0.0 ), vec2( 0.0 ) ).rgb; // disable anisotropic filtering
#else
return texture2D( envMap, uv ).rgb;
#endif
}
// These defines must match with PMREMGenerator
#define r0 1.0
#define v0 0.339
#define m0 - 2.0
#define r1 0.8
#define v1 0.276
#define m1 - 1.0
#define r4 0.4
#define v4 0.046
#define m4 2.0
#define r5 0.305
#define v5 0.016
#define m5 3.0
#define r6 0.21
#define v6 0.0038
#define m6 4.0
float roughnessToMip( float roughness ) {
float mip = 0.0;
if ( roughness >= r1 ) {
mip = ( r0 - roughness ) * ( m1 - m0 ) / ( r0 - r1 ) + m0;
} else if ( roughness >= r4 ) {
mip = ( r1 - roughness ) * ( m4 - m1 ) / ( r1 - r4 ) + m1;
} else if ( roughness >= r5 ) {
mip = ( r4 - roughness ) * ( m5 - m4 ) / ( r4 - r5 ) + m4;
} else if ( roughness >= r6 ) {
mip = ( r5 - roughness ) * ( m6 - m5 ) / ( r5 - r6 ) + m5;
} else {
mip = - 2.0 * log2( 1.16 * roughness ); // 1.16 = 1.79^0.25
}
return mip;
}
vec4 textureCubeUV( sampler2D envMap, vec3 sampleDir, float roughness ) {
float mip = clamp( roughnessToMip( roughness ), m0, CUBEUV_MAX_MIP );
float mipF = fract( mip );
float mipInt = floor( mip );
vec3 color0 = bilinearCubeUV( envMap, sampleDir, mipInt );
if ( mipF == 0.0 ) {
return vec4( color0, 1.0 );
} else {
vec3 color1 = bilinearCubeUV( envMap, sampleDir, mipInt + 1.0 );
return vec4( mix( color0, color1, mipF ), 1.0 );
}
}
#endif
""";
