nuclear@4: uniform sampler3D vol_tex;
nuclear@4: uniform sampler1D xfer_tex;
nuclear@4: 
nuclear@4: void main()
nuclear@4: {
nuclear@8: 	vec3 tc = gl_TexCoord[0].xyz;
nuclear@8: 	float max_manh_dist = max(tc.x, max(tc.y, tc.z));
nuclear@8: 	float min_manh_dist = min(tc.x, min(tc.y, tc.z));
nuclear@8: 	float border = step(0.0, min_manh_dist) * (1.0 - step(1.0, max_manh_dist));
nuclear@8: 
nuclear@4: 	vec4 voxel = texture3D(vol_tex, gl_TexCoord[0].xyz);
nuclear@4: 	vec4 color = texture1D(xfer_tex, voxel.a);
nuclear@4: 
nuclear@8: 	float alpha = color.a * border;
nuclear@8: 	if(alpha < 0.001) discard;
nuclear@8: 
nuclear@8: 	gl_FragColor.rgb = voxel.rgb;
nuclear@8: 	gl_FragColor.a = alpha;
nuclear@4: }