elene@24: uniform sampler3D tex;
elene@24: uniform float tmin;
elene@24: uniform float tmax;
elene@24: 
elene@24: float transfer(float x, float tmin, float tmax)
elene@24: {
elene@24: 	float dt = 0.25 * (tmax - tmin);
elene@24: 	return smoothstep(tmin - dt, tmin + dt, x) *
elene@24: 		(1.0 - smoothstep(tmax - dt, tmax + dt, x));
elene@24: }
elene@24: 
elene@24: void main()
elene@24: {
elene@24: 	float texel = texture3D(tex, gl_TexCoord[0].xyz).x;
elene@24: 	float val = transfer(texel, tmin, tmax);
elene@24: 
elene@24: 	gl_FragColor = vec4(val, val, val, 1.0);
elene@24: }