export default /* glsl */` #ifdef USE_NORMALMAP uniform sampler2D normalMap; uniform vec2 normalScale; #endif #ifdef OBJECTSPACE_NORMALMAP uniform mat3 normalMatrix; #endif #if ! defined ( USE_TANGENT ) && ( defined ( TANGENTSPACE_NORMALMAP ) || defined ( USE_CLEARCOAT_NORMALMAP ) ) // Per-Pixel Tangent Space Normal Mapping // http://hacksoflife.blogspot.ch/2009/11/per-pixel-tangent-space-normal-mapping.html vec3 perturbNormal2Arb( vec3 eye_pos, vec3 surf_norm, vec3 mapN ) { // Workaround for Adreno 3XX dFd*( vec3 ) bug. See #9988 vec3 q0 = vec3( dFdx( eye_pos.x ), dFdx( eye_pos.y ), dFdx( eye_pos.z ) ); vec3 q1 = vec3( dFdy( eye_pos.x ), dFdy( eye_pos.y ), dFdy( eye_pos.z ) ); vec2 st0 = dFdx( vUv.st ); vec2 st1 = dFdy( vUv.st ); float scale = sign( st1.t * st0.s - st0.t * st1.s ); // we do not care about the magnitude vec3 S = normalize( ( q0 * st1.t - q1 * st0.t ) * scale ); vec3 T = normalize( ( - q0 * st1.s + q1 * st0.s ) * scale ); vec3 N = normalize( surf_norm ); mat3 tsn = mat3( S, T, N ); mapN.xy *= ( float( gl_FrontFacing ) * 2.0 - 1.0 ); return normalize( tsn * mapN ); } #endif `;