@lume/three-instanced-mesh/monkey-patch/uv_pars_vertex.glsl.js

Scene graph level abstraction for three.js InstancedBufferGeometry

export default /* glsl */ `
#if defined( USE_MAP ) || defined( USE_BUMPMAP ) || defined( USE_NORMALMAP ) || defined( USE_SPECULARMAP ) || defined( USE_ALPHAMAP ) || defined( USE_EMISSIVEMAP ) || defined( USE_ROUGHNESSMAP ) || defined( USE_METALNESSMAP )
 
  varying vec2 vUv;
  
  uniform mat3 uvTransform;

#endif

#ifdef INSTANCE_TRANSFORM

mat3 inverse(mat3 m) {

  float a00 = m[0][0], a01 = m[0][1], a02 = m[0][2];

  float a10 = m[1][0], a11 = m[1][1], a12 = m[1][2];

  float a20 = m[2][0], a21 = m[2][1], a22 = m[2][2];

  float b01 = a22 * a11 - a12 * a21;

  float b11 = -a22 * a10 + a12 * a20;

  float b21 = a21 * a10 - a11 * a20;

  float det = a00 * b01 + a01 * b11 + a02 * b21;

  return mat3(b01, (-a22 * a01 + a02 * a21), ( a12 * a01 - a02 * a11),
              b11, ( a22 * a00 - a02 * a20), (-a12 * a00 + a02 * a10),
              b21, (-a21 * a00 + a01 * a20), ( a11 * a00 - a01 * a10)) / det;
}

//for dynamic, avoid computing the matrices on the cpu
attribute vec3 instancePosition;
attribute vec4 instanceQuaternion;
attribute vec3 instanceScale;

#if defined( INSTANCE_COLOR )
  attribute vec3 instanceColor;
  varying vec3 vInstanceColor;
  attribute float instanceOpacity;
  varying float vInstanceOpacity;
#endif

mat4 getInstanceMatrix(){

  vec4 q = instanceQuaternion;
  vec3 s = instanceScale;
  vec3 v = instancePosition;

  vec3 q2 = q.xyz + q.xyz;
  vec3 a = q.xxx * q2.xyz;
  vec3 b = q.yyz * q2.yzz;
  vec3 c = q.www * q2.xyz;

  vec3 r0 = vec3( 1.0 - (b.x + b.z) , a.y + c.z , a.z - c.y ) * s.xxx;
  vec3 r1 = vec3( a.y - c.z , 1.0 - (a.x + b.z) , b.y + c.x ) * s.yyy;
  vec3 r2 = vec3( a.z + c.y , b.y - c.x , 1.0 - (a.x + b.x) ) * s.zzz;

  return mat4(

      r0 , 0.0,
      r1 , 0.0,
      r2 , 0.0,
      v  , 1.0

  );

}

#endif
`;