message: wip, gpu mc webgl1 tweak
diff: @@ -182,8 +182,8 @@ void main(void) {
  // group id
  #if __VERSION__ == 100
  // webgl1 does not support 'flat' interpolation (i.e. no interpolation)
  - // so we provide a constant that stands for 'unknown-group'
  - gl_FragData[0].w = 16777216.0;
  + // so we ensure a constant group id per triangle
  + gl_FragData[0].w = decodeFloatRGB(voxel(coord3d).rgb);
  #else
  gl_FragData[0].w = t < 0.5 ? decodeFloatRGB(d0.rgb) : decodeFloatRGB(d1.rgb);
  #endif
  