On Wed, 4 Sep 2002, Timothy Moore wrote:
> I don't know whether this has been covered before but I have some
> questions on clipping whilst using surfaces. Before I go on I will state
> that pymol produces the best surfaces for my purposes, of any program I
> have seen so far. However, (sorry there is always room to be better! ;)
> ) the ideal situation would be if the cut "surface" was represented as
> if the molecule was solid. ie: you didn't see inside the molecule
> itself, but the cut plane. Is there any way to do this (e.g. via povray
> rendering)? I appreciate it is probably not exactly easy though.
>
> Alternatively, it would be good if it was possible to make the inside
> surface of a molecule appear completely black without resorting to
> ambient=0.
Tim,
What you're asking for is mathematically non-trivial. In fact, I
haven't even solved this problem for spheres yet in the raytracer.
As far as I can tell, setting ambient to zero alone doesn't quite do
the job, since some triangles still get lit by the light source.
The best combination I can find is:
set ambient=0
set direct=0.7
set reflect=0.0
set backface_cull=0
While gives no shadows an only a few artifacts.
As an alternative, you might just consider showing the inside of the
surface directly...that will create less visual artifacts, and so long as
ambient and direct are sufficiently low, it will look reasonable in "ray".
util.ray_shadows("heavy")
set two_sided_lighting=1
set backface_cull=0
Cheers,
Warren
