I'm not 100% sure: try using [all AOV] in the advanced settings.

Then i suggest to give a try here: LINK
The atmosphere solution will take care of the mia material.

Marco Cattaneo wrote:

HI,

I'm starting to really like 3Delight but there are a couple of things that still can't understand and let work.

First problem, I can't get Mia_materials to get occlusion effect, models with Mia_mats attached just shows pitch black in the "occlusion" AOV

Ex 1:  everything has a simple maya lambert assigned, except the dino model, that has a Mia_material_X and as you can see, it's just a black hole in the occlusion AOV. I even made the model visible to to Diffuse Rays with a geoAttrib node. It happens by using both Point cloud  full GI and simple "occlusion" method

Using Point Cloud:
https://docs.google.com/open?id=0B8EjKX … 1dJclNNNjg

Using simple Occlusion:
https://docs.google.com/open?id=0B8EjKX … DJiaUNhMzg

Is there any parameter I need to tweak to get Mia_materials work with Ambient Occlusion?


Another quick question: Is there a way to specify on a object (or material) basis, how much it will contribute to Point cloud color bleeding on surrounding models?

Hey
Guys!

Even I had a similar problem with mia materials ...
For the occlusion problem Aghiles made a quick change for me ..
Here it is

#ifdef USE_AOV_aov_occlusion
#if 0    
extern varying color aov_occlusion;
    if( isoutput(aov_occlusion) )
    {
        aov_occlusion = ambient_occlusion;
    }
#endif
#endif

Search for #ifdef USE_AOV_aov_occlusion in mia_material.h or in mia_material_x.h

and replace the remaining code with the above one, this should sort out things for occlusion..

However I too have problems with the GI part which I am sure they are looking into..

Regards

victor wrote:

Hi,

It seems you haven't set a "Bake Camera" parameter in the "Point Cloud" section. Point-cloud file contains only objects that are in the camera. So in your case, objects that are behind camera don't affect to AO.

This has nothing to do with his problem, victor.

Actually I'm having similar troubles with mia/misss materials and PTC. I hope developers will take a look on this. Anyway, usin simple Blinn is still the best solution for most of the cases. I just wish I wouldn't have to use misss skin materials. If there was simple way of adding SSS attributes to bling like glossy reflections, that would be awesome. ;)

Last edited by clojster (2012-05-07 11:48:30)

@Caveman: Thanks man, I will try that code for sure...

@victor: As clojster said, the problem has nothing to do with setting up a bake camera in the point cloud section: As long as you add the dicing attributes to let the point cloud being correctly calculated (backfacing) you should at least get something usable.

You can create a very simple scene to test this out. Place a plane, a sphere, make them visible to occlusion rays, assign a mia material to them... And you should be able to see that in the beauty render the occlusion is present, but in the aov_occlusion models shows black. Infact, the second render I posted is done by using raytraced occlusion found in the GI tab. No point cloud involved.

I made a couple of considerations. Since both occlusion and color bleeding are still correctly calculated, I just thought about using mia materials for all AOV's but the occlusion, and just use the mib_ambient_occlusion node to achieve a full AO pass, since it's fast and simple to setup.

Anyway, I still have problems with refractions, SSS. I'm going to probably make a big thread to not spam all the forums, so I can ask more questions.

Like SSS. I can make it to work, but I really can't understand how all the parameters must be setup and how they interact with each other. As a Mental ray guy I know that as long as I stick with real world scales, I get correct natural behaviour. But using the Misss_fast_skin AND make it work with the SSS portion of 3Delight it's driving me crazy.

One final question: is the 3Delight rewritten Mia_material still a full converving energy shader? (like the original)

Last edited by Marco Cattaneo (2012-05-07 20:25:56)

Hi cleger!

First of all, thank you for the usefull reply (and for the Uber_ptc stuff, for that matter :D I'm starting to use your shaders)!

As far as I tested out, yes, by using 3delight SSS I can get good basic SSS effects (the example scene included in the package is really straight forward)...

The problem is when I add the Misss_fast_skin shader into the equation, since I then have something like twice the parameters, which are basically (as I understand) just doing the same thing (but twice).

I do lot of character work, so I'd want to use textures to control epidermal and subdermal scatter... Which is what I can achieve with Misss_fast_skin_maya normally... But used in conjunction with 3Delight parameters results in very odd renders.

So, there is a way to use 3Delight standard SSS parameters (which makes sense to me) and simple add textures to a model? (after all we sometimes need more than milk, wax, or cartoonish characters)

I'm really looking forward a solution, since the more I use 3Delight, the more mental ray feels... "heavy" and slow...

I can confirm that there is a problem with the MIA materials and the occlusion AOV. The fix will be available in the next package.
-- aghiles

aghiles wrote:

I can confirm that there is a problem with the MIA materials and the occlusion AOV. The fix will be available in the next package.
-- aghiles

That's good. I don't know if this problem is related to occlusion AOV or it's some kind of other bug, but this is what happens with mia materials and PTC:





First image is with Blinn with checker assigned, the second image is mia_material with checker.

There is one directional light in the scene with ray traced shadows.

As you can see, the problem is, that not lit area of the cube with mia_material doesn't have a texture. It's just grey.
This applies also to miss_fast_skin shader. I didn't test the others...

Example scene is here: http://dl.dropbox.com/u/2250906/test_mia.ma

Thanks for having a look on this.

Jakub.