1.1 --- a/sdr/volray.p.glsl	Wed Apr 11 06:44:06 2012 +0300
     1.2 +++ b/sdr/volray.p.glsl	Wed Apr 11 16:59:45 2012 +0300
     1.3 @@ -40,15 +40,19 @@
     1.4  	gl_FragColor = vec4(color, 1.0);
     1.5  }
     1.6  
     1.7 -float eval(vec3 pos)
     1.8 +float eval(vec3 pos, out vec3 grad)
     1.9  {
    1.10  	vec3 tc = pos * 0.5 + 0.5;
    1.11  
    1.12  	if(tc.x < 0.0 || tc.y < 0.0 || tc.z < zclip || tc.x > 1.0 || tc.y > 1.0 || tc.z > 1.0) {
    1.13 +		grad = vec3(0.0, 0.0, 0.0);
    1.14  		return 0.0;
    1.15  	}
    1.16  
    1.17 -	return texture1D(xfer_tex, texture3D(volume, tc).a).x;
    1.18 +	vec4 texel = texture3D(volume, tc);
    1.19 +	grad = texel.xyz;
    1.20 +
    1.21 +	return texture1D(xfer_tex, texel.a).x;
    1.22  }
    1.23  
    1.24  #define OFFS	0.01
    1.25 @@ -63,12 +67,8 @@
    1.26  		vec3 pos = ray.origin + ray.dir * t;
    1.27  		t += ray_step;
    1.28  
    1.29 -		float val = eval(pos);
    1.30  		vec3 norm;
    1.31 -
    1.32 -		norm.x = eval(pos + vec3(OFFS, 0.0, 0.0)) - val;
    1.33 -		norm.y = eval(pos + vec3(0.0, OFFS, 0.0)) - val;
    1.34 -		norm.z = eval(pos + vec3(0.0, 0.0, OFFS)) - val;
    1.35 +		float val = eval(pos, norm);
    1.36  
    1.37  		col += shade(ray, pos, normalize(norm)) * val * energy;
    1.38  		energy -= val;