light lwlightdistant ( float intensity = 1;
                     color lightcolor = 1;
                     point from = point "shader" (0,0,0);
                     point to = point "shader" (0,0,1);
                     float  trace = 0;
                     float  samples = 4;
                     float __nondiffuse = 0;
                     float __nonspecular = 0; ) {
	solar (to-from, 0) {
		Cl = intensity * lightcolor;
		
		if (trace != 0) {
		   color s = shadow("raytrace", Ps, "samples", samples);
		   Cl *= 1 - s;

	    }
    }
}