Normal / Bump Replacement

[Falam]

This is a awesome shader I came across, unfortunately it's only available for Maya as I was told directly from Stefan It would be nice if this could be written for Mental Ray and Softimage

[forton]

He says it's implemented for mental ray, wouldn't that work in softimage then?
I think it's the same shader that exist for lightwave, a guy named Denis Pontonnier implemented a series of renderman shaders into nodes for Lightwave http://dpont.pagesperso-orange.fr/plugi ... des_2.html, making lightwave renderer from basic to pretty advanced for it's time.
Some of these I would love to see in mentalray!

P.S. I think the code is freely available, could someone please...? ;)

[rray]

That would probably be easy to pack for SI, sadly it's not public.
There's the 'parallax' shader by Ben Rogall but it's 32 bit only.
out of options...

[Hirazi Blue]

The version downloaded directly from Ben Rogall's site
seems to include 64 bit dlls as opposed to the one in the rray.de local backup.
Haven't tested this shader myself, though.
;)

[rray]

Ah missed that one. He 'advertises' it as slower than displacement, but that's with shadows it seems. Without self shadowing it should be faster.

[Falam]

This can achieve displacement-like effects, except at the edges of an object ?

Maybe I'm missing something How is this different from the Normal Map shader within Softimage ?

[rray]

It does parallax mapping (see his site) which shifts surface details around instead of just modifying the shading. The shader you discovered does modify the relief in addition, which is even one step cooler.

[Falam]

It does parallax mapping (see his site) which shifts surface details around instead of just modifying the shading. The shader you discovered does modify the relief in addition, which is even one step cooler.

Can we get that one extra step cooler ?

[rray]

I don't think so, unless Ben's shader does that already (Which I guess it doesn't, but not sure)
Let us know if you get some nice results out of it )

[Falam]

I don't think so, unless Ben's shader does that already (Which I guess it doesn't, but not sure)
Let us know if you get some nice results out of it )

Will do, I hope I do

[Daniel Brassard]

Relief mapping shader information.

http://http.developer.nvidia.com/GPUGem ... ter08.html

I love reading the GPU Gems books. So much information.

[BenR]

I haven't thought about that shader in a long time. I wonder if it will work with recent versions of Soft. Anyway, the algorithm I implemented uses ray-marching to find the intersection point ("steep parallax mapping"). This should provide the same results as the relief mapping algorithms, which I believe is a synonym. The GPU Gems article that Daniel referenced is really interesting. It includes a method of improving efficiency using distance maps and "sphere tracing" which I was not aware of. It's interesting that all of these methods were developed with real-time rendering in mind.
Ben

[Falam]

I haven't thought about that shader in a long time. I wonder if it will work with recent versions of Soft. Anyway, the algorithm I implemented uses ray-marching to find the intersection point ("steep parallax mapping"). This should provide the same results as the relief mapping algorithms, which I believe is a synonym. The GPU Gems article that Daniel referenced is really interesting. It includes a method of improving efficiency using distance maps and "sphere tracing" which I was not aware of. It's interesting that all of these methods were developed with real-time rendering in mind.
Ben

Maybe you can help me Ben or someone can



The shader is not working, rather it's rendering my object completely black ?

Daniel - Sorry if I'm mis-understanding, is that link you posted similar in how it displaces geometry to the link I had originally posted ? One of the issues I have with Normal Mapping is AA, what Stefan produced which is only a maya shader is breathless, not quite sure I understand the technology behind it, it is effective for Mental Ray. Although if you are using a RenderMan compliant render which I also use, displacements can be just as fast. I don't know how to write Renderman shaders, and the tools that are available that are good and free are only for Linux

[BenR]

Sorry, that shader is so old that I am not surprised that is not working.
Ben

[Falam]

Sorry, that shader is so old that I am not surprised that is not working.
Ben

[grahamef]

Sorry, that shader is so old that I am not surprised that is not working.
Ben

Someone -- I'm pretty sure it was Daniel Rind -- had a simpler (i.e. non-steep) parallax map shader that was a compound of standard nodes. I believe it was on xsibase but there may still be a copy of it floating around somewhere. In fact I might even have it somewhere among my files.

EDIT: Found it!