 uniform vec3 sampleDistance;
 uniform float alphaThresholdForDepth = 0.1;
 const int layerCount = 4;
-uniform vec4 layerCuts = vec4(-0.15, 0, 0.1, 0);
 uniform vec4 layerPlanes[layerCount - 1];
 
 uniform sampler3D volumeSampler;

  }
}

vec4 calculateSampleColor(in uint remainingActiveObjects, in int activeObjectCount,
    in vec4 startPos_eye)
{

  if (maxAge == 0)
    discard;  // no fragment, early exit

  int activeObjects = 0;
  FragmentData currentFragment;
  FragmentData nextFragment;
