text: export default /* glsl */`
  #ifdef USE_TRANSMISSION
  
  	float transmissionFactor = transmission;
  	float thicknessFactor = thickness;
  
  	#ifdef USE_TRANSMISSIONMAP
  
  		transmissionFactor *= texture2D( transmissionMap, vUv ).r;
  
  	#endif
  
  	#ifdef USE_THICKNESSMAP
  
  		thicknessFactor *= texture2D( thicknessMap, vUv ).g;
  
  	#endif
  
  	vec3 pos = vWorldPosition;
  	vec3 v = normalize( cameraPosition - pos );
  	vec3 n = inverseTransformDirection( normal, viewMatrix );
  
  	vec3 transmission = getIBLVolumeRefraction(
  		n, v, roughnessFactor, material.diffuseColor, material.specularColor, material.specularF90,
  		pos, modelMatrix, viewMatrix, projectionMatrix, ior, thicknessFactor,
  		attenuationTint, attenuationDistance );
  
  	totalDiffuse = mix( totalDiffuse, transmission, transmissionFactor );
  #endif
  `;
  