varying vec3 MCposition;
varying vec4 Color;
varying float LightIntensity; 

uniform sampler3D Noise3;
uniform float Min, Max;
uniform float Scale;

void main()
{
	vec4  noisevec  = texture3D( Noise3, Scale*MCposition );

	float size = noisevec[0] + noisevec[1] + noisevec[2] + noisevec[3];
	size = .5 * ( size - 1. );
	// size = size * size * size;
	// float a = smoothstep( Min, Max, size );

	if( size < Min )
		discard;

	if( size > Max )
		discard;

	gl_FragColor = vec4( LightIntensity*Color.rgb, 1. );
#ifdef WANT_RED_AT_EDGES
	if( size < Min + .05 )
		gl_FragColor = vec4( LightIntensity*vec3(1.,0.,0.), 1. );
#endif
}