Mr and render elements woes

[theotheo]

Hi guys,

Im doing some investigating with mr and multipass rendering using render elements and the p_mega_tk shader/buffer writer.

I have some questions i hope some of you mental ray gurus would
take the time to answer.

Does anyone know why the arch & design shader doesn't work with render elements, why it does not split the passes up correctly, i'm curious to why its happening, is it max's implementation of mr that "breaks" it? Just like you have to re-render all the elements to use them, instead of just spitting them out like when using the p_mega_tk or scanline+render elements.

We got a copy of xsi at work here but i havnt used it, but the xsi guy tells me it can split the passes automatically without the need to do re-renders, can someone confirm this? Is this also true for mr in maya?

Thanks :)

-theo

[Drachen]

We are also experiencing discrepancies between the normal render output, and the composite render from the render elements. Most noticably the shadows. Here is an example. There are significant differences in shadow density and color. The bottom image is a very simple composite of the Diffuse and Shadow Layers. The Shadow layer is on top of the Diffuse layer and is simply using its built in alpha. Blend mode is Normal, and Opacity is 100%.

http://www.corganmedialab.com\forum_posts\LAMRUG\render_e lements\comparison.png

[Puppet]

Does anyone know why the arch & design shader doesn't work with render elements
Because 3dsmax and A&D have different techniques and passes.
Just view what passes split out render elements and A&D.

to Drachen:
Yes, it's known problem for all renders.
http://www.puppet.cgtalk.ru/adv_lambert.jpg
But p_MegaTK technique have no these problems :) (shadow artifacts and intensity difference) And rendered more faster(for one render) then all your render element or render layers.

P.S. to Drachen, your image link is incorrect. Here is right:
http://www.corganmedialab.com/forum_posts/lamrug/render_elements/comparison.png

[theotheo]

Yes the mega_tk shader is the way to go, i've been using it alot latly and it is fullfulling most of my needs, still struggeling with getting the fast sss shader to work correctly with it, but i guess thats a 3dsmax sss lightmap issue.

Btw, thanks for the shader puppet, you're a genius :)

-the0