k3d/share/shaders/k3d_crayon.sl:20:	density1 - if different density0 this is the density when t = 1, with a smooth
k3d/share/shaders/k3d_crayon.sl:65:			float density1 = .5;
k3d/share/shaders/k3d_crayon.sl:71:    float density = density0 + t * (density1 - density0);
