k3d/share/shaders/k3d_volcube.sl:10:   Do_Shading          - if 1, shading will be calculated.
k3d/share/shaders/k3d_volcube.sl:193:	     float  Do_Shading     = 1;
k3d/share/shaders/k3d_volcube.sl:243:	    if(Do_Shading > 0){
