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Lex-DRL
06-05-2010, 10:06 PM
There is very interesting and effective technique called Relief Mapping, which is based on algorithms described by Fabio Policarpo, Manuel M. Oliveira and Joao L.D. Comba, in the "Real-Time Relief Mapping on Arbitrary Polygonal Surfaces" document.
AFAIK, it was "hot topic" few years ago.
http://fabio.policarpo.nom.br/Demos.html
http://www.inf.ufrgs.br/~oliveira/RTM.html

Looks like technology is successfully developed for production-level renders, and there are MAX plugins for it. But I can't find any Relief Mapping shader for Maya/MR, no matter how hard I'm googling. I can't believe, that there is no implementation of this technology for Maya. It looks like I'm searching it in kind of wrong way.

It would be great if anyone share links to Relief-Mapping-for-Maya shaders or at least explain what happen with technology (is it died before it was finally released?).

P.S.: Parallax7 (http://www.pixero.com/files/Parallax7.zip) is something "too beta"; Fdisplace is not available now and www.thepixelmachine.com redirects to completely different software - topogun; minrelief (http://www.minning.de/software/minshaders#minRelief) isn't published. But I can't imagine that the whole technology (which was developed for years) starts from and ends with this 3 links.

joie
09-15-2010, 04:18 PM
I feel the same as you..., no working mental ray shaders is it possible?.

InfernalDarkness
09-15-2010, 06:56 PM
What is the difference or benefit of "relief mapping" versus displacement mapping and/or normal mapping?

At a glance, and having read the sites posted, it would appear relief mapping is just one or both of those methods, and we use those all the time already... Please correct my error - I'm not seeing the point of relief mapping.

Edit: nevermind, this paragraph answered my question:

Relief Texture Mapping is a technique that supports the representation of 3-D surface detail, producing self-occlusion, self-shadowing, view-motion parallax, and silhouettes. This technique produces correct views of 3-D surfaces and scenes by augmenting textures with per texel depth. The details are described in a series of documents, including papers, my Ph.D. dissertation, technical reports, demos with source code, and videos. Check them out and welcome to the Relief Texture Mapping World!

Lex-DRL
09-16-2010, 06:19 AM
For those like InfernalDarkness who doesn't know about the topic yet:

In few words, Relief Mapping is kind of advanced Normal/Bump-Mapping, which looks like displacement but is still just a texture effect. So it renders almost as fast as normal-mapping, has a few limitations (same as normal-mapping), but allows you to have fantastic level of detail in your model with no cost (unlike displacement).

The easiest way to understand it better is this (http://www.youtube.com/results?search_query=Relief+Mapping&page=&utm_source=opensearch).

Also:
there are advanced versions of Relief Mapping - Curved Relief Mapping (http://fabio.policarpo.nom.br/videos/Curved_ReliefMapping_Video.zip) and Multilayer Relief Mapping (http://fabio.policarpo.nom.br/videos/Multilayer_ReliefMapping_Video.zip). This is what I'm really dreaming about.

ContrivanCe
01-24-2011, 01:17 PM
So no one has gotten this to work yet?
Someone has, judging by this video:
http://www.youtube.com/watch?v=cJJpSM0BTWs

If anyone gets this to work? Can someone tell us how?

Radon
01-24-2011, 05:15 PM
That video is of a 'real time' shader that only works in Maya's viewport, you can't actually render it.

I've been looking and looking for some way to do this but nobody seems to have a recent plugin that renders anything close to fast.

Games with DX11 are moving towards Tessellation, which is just a very efficient displacement for games.

http://www.youtube.com/watch?v=Smml32f5SqM&hd=1

http://www.geforce.com/#/Optimize/Guides/dx11-guide

This algorithm is what I really want to get in Maya.

Lex-DRL
01-24-2011, 07:58 PM
2 ContrivanCe
Unfortunately, there is still no shader for maya. At least, I couldn't find it. Even though I've sent emails to some people who was developing this technique in the past. All I've got is answers like "sorry, but can't help you since I'm not at this thing anymore".

But some guys at russian forums told me something like that:
There is no need for relief mapping shaders at video production. We've got a displacement and that's it. Just use renderman 'cause it's render time for displacement is almost equal to relief mapping render time. This feature is developed, again, not for CG, but for games. And it has implementations in next-gen engines, like UDK. No relief mapping in maya, accept it.
And (just like Radon wrote) nowadays games' development direction is to get true realtime displacement.

I haven't been tested renderman / unreal engine yet, so all I can do is retell what I've read.

MasonDoran
01-25-2011, 02:24 PM
This is done with real time engines specifically, which are working with the graphics card and why you dont see it in Mental Ray.

To get it for Mental Ray, it would require writing a shader for it...and then of course the programmer would have to be nice enough to share it to the community.

MasonDoran
01-25-2011, 02:25 PM
And to get the realtime version...you would need to write a CGFX shader for it.

haggi
01-26-2011, 10:04 AM
There are some drawbacks with parallax mapping.

Pros:

Needs less memory than true displacement because it needs less geometry
Cons:

Displacement cannot go outwards
You have problems with intersections.
You will have problems with shadowing, you need to solve it in the shader
Not to miss any details in the heightmap you need a quite small stepsize for every sample hitting the relief map what has impact on rendertime.
The interesting operations which speedup the calculation in games does not work 1:1 in software rendering.
So even if it is a cool technology, with current 64bit machines and intelligent geometry handling, it is much more efficient to use true displacement even if it may render a little bit longer, you will have less problems. I suppose thats the reason why noone is using parallax mapping in software rendering.

cowsmanaut
07-26-2011, 03:28 AM
actually it looks like those some of those drawbacks are no longer..
http://www.youtube.com/watch?v=W3aoQpECaU0

this seems to do edge correction to correct the silhouette.. the only thing is in tracing down this guys work I had seen a mention of a maya shader, but it appears his website mentioned is no longer. He supposedly supplied his code for this though.. so if someone smart could find it, I'm sure somebody could make a render time shader for it... after all, renderman isn't cheap..

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