Hey there,
I'm wondering if there's an option somewhere in 3ds max' RTT dialogue to limit the ray distance in the direction that is not controlled by the cage - so basically the opposite normal direction.
I made a quick graphic to illustrate my question:
Replies
1) Morphing the mesh so its flat and rendering it. This could make the normals inaccurate but then that shouldn't' be any different than a normal map applied to a character? You'll want to test that out thoroughly...
2) Apply a 2 sided material to your low poly, make the material on the backside a solid green 255 color with the self illumination cranked up to 100. Set the background color to the same green 255 and render just the low poly, this should in theory give you an opacity mask... maybe... Haven't tested it, don't have time.
You might want to check out xNormal, it might have a setting like that, if not you might what to drop the suggestion on Santiago and see if he can think of a way to get that worked out.
The alpha depends on the silhouette of the highpoly though, so your suggestion with 2) wouldn't work if I got it right.
I will go for your first suggestion, though I have serious doubts that the shading will come out correct in the UDK. However, it seems I have no other option...
xN currently does not support alpha to skip ray collisions, that's a thing we want to add for future releases.
A workaround might be to explode or to detach the top part of that mesh and render separately. Another option is to use a blocker anti-portal there ( take a look to xN's blockers ).