Composite Materials and Ray Traced Shadows

[Drachen]

We are using 3ds Max 9 (32 Bit) and the bundled Mental Ray. We do alot of exterior Architectural shots, where the light source is required to be a substantial distance away from the ground plane. Because of this MR Shadow Maps are not adequate due to the limit of shadow map size. We also use composite materials to create textures for parking lots, and large ground planes. When a Raytraced Shadow hits geometry with a composite material, the area where the shadow hits renders transparent. If the same is done with a blend material the shadow renders correctly, however the edges of the mask render transparent. We have used a Mix Map in the diffuse slot successfully, however with this setup we cannot create painted decals on glass, we can only crete color patterns on a surface. I suppose that the same mix map could be used in reflection, and refraction slots, but that would be overly time consuming.

Is there a layered shader compatible with Mental Ray? And is there a raytraced shadow type compatible with Mental Ray?

Thanks,
Lee

[Brian Bradley]

Hi Lee,

Not sure I understand how /why you are using your
stated setup. Why does the light source need to be
such a distance? I assume poss you are talking about
large area Arch viz shots as opposed to a single
building shot?
Would it be possible to post up a simple file (using
primitives or such that highlightd the problem you
are running into? Suggestions are always easier to
make when you 'see' the problem in action.

Regards
Bri

Mental Ray Training for Max users everywhere.
http://www.mentalboutmax.com

[Drachen]

Brian,

Sorry for the delay. I am now posting an example scene if the problem. Thanks.

Lee

http://www.corganmedialab.com/forum_pos ... mrtest.max (http://www.corganmedialab.com/forum_posts/LAMRUG/comp_shaodws/maxmrtest.max)