   gl_Position =  VPMatrix * ModelMatrix * pos;
   EmitVertex();
 
-  //-X
+  // -X
+  // f_VoxelColor.rgb = 0.8 * voxelColor.rgb;
   EmitVertex(); //for degenerate purpose
   //f_color = vec4( 0.5, 0.5, 0.5, 1 );
   pos.xyz = center.xyz + vec3(-1,-1,-1) * halfVox;


  const vec4 center = gl_in[0].gl_Position;
  vec4 pos = center;

  pos.xyz = center.xyz + vec3(-1,-1,1) * halfVox;
  gl_Position =  VPMatrix * ModelMatrix * pos;
  EmitVertex();

  pos.xyz = center.xyz + vec3(1,-1,1) * halfVox;

  gl_Position =  VPMatrix * ModelMatrix * pos;
  EmitVertex();

  // -Y
  // f_VoxelColor.rgb = 0.8 * voxelColor.rgb;
  EmitVertex();

  pos.xyz = center.xyz + vec3(-1,-1,-1) * halfVox;
