danini-the-panini/mittsu-opengl

#ifdef USE_SKINNING

    mat4 skinMatrix = mat4( 0.0 );
    skinMatrix += skinWeight.x * boneMatX;
    skinMatrix += skinWeight.y * boneMatY;
    skinMatrix += skinWeight.z * boneMatZ;
    skinMatrix += skinWeight.w * boneMatW;
    skinMatrix  = bindMatrixInverse * skinMatrix * bindMatrix;

    #ifdef USE_MORPHNORMALS

    vec4 skinnedNormal = skinMatrix * vec4( morphedNormal, 0.0 );

    #else

    vec4 skinnedNormal = skinMatrix * vec4( normal, 0.0 );

    #endif

#endif