3ds RTT: limit ray distance in both directions

toolpaddz

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:

toolpaddz

shameless bump. Anyone? I really need a solution here...

Mark Dygert

I don't think there is a negative depth setting anywhere... and off the top of my head I can only think of a few crazy work around that probably won't work.
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.

toolpaddz

thanks mark, I already tried xNormal. Either I am too dumb to find such a setting or it doesn't exist. Might consider dropping Santiago a mail.

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...

jogshy

Old xN versions used a double-sided cage to limit the rays as you want... but I removed that because it was very difficult for the user to edit the back-facing part of the cage.

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 ).

toolpaddz

thanks for the suggestions. I was quite excited about the ray blockers because as you described them, they should eliminate my problems. However, I cannot get them to work properly. I set it up as a lowpoly plane (about 12 tris or so) at about the black spot I marked at the top, reaching from the very bottom of the model to nearly the very top. I also paid attention to not let it interfere with the highpoly nor the lowpoly as not to block the rays before they reach the hp. The rendered normalmap looks exactly the same as before, though. Am I misunderstanding the way the blockers work?