k3d/share/shaders/k3d_volcube.sl:214:    float  shad_sum     = 0;
k3d/share/shaders/k3d_volcube.sl:280:		shad_sum += max(0,cur_density);
k3d/share/shaders/k3d_volcube.sl:284:		shad_sum = (cur_density) * (1-shad_sum) + shad_sum;
k3d/share/shaders/k3d_volcube.sl:286:	    if(shad_sum >= .5){
