spherical harmonics

[aweidenhammer]

Ok, so I've played around and can't quite get it working. Since there are no docs that walk through the methods, I'll step through what I'm doing, and hopefully, somebody will tell me what I'm doing wrong.

1. I have a very simple interior test scene. Walls have regular subdivisions to get decent SH data.
2. I'm also using a physical camera with exposure adjusted (don't know if this should be used with SH).
3. vrayCommon - I set the baking engine to SH. settings set to occlusionAll (3 objects in total) set output .vrsh file. (4 bands 3 bounces)
4. render from camera, it precalculates the vrsh file, displays black in the framebuffer.
5. Turn baking to none
6. In Indirect Globals, I set the primary engine to SH, and secondary to none.
7. Load the .vrsh file in the settings, hit render from camera
CRASH Maya

Any thoughts?

[Yannick]

I haven't try yet but according to the doc, it is for exterior only:

Disadvantages:

* this method is not suitable for high frequency lighting.
* it can's be used for closed scenes.
* it could produce unwanted artefacts on closely placed surfaces, due to their coarse subdivision.
* it captures diffuse indirect illumination only

[aweidenhammer]

can you link me to where you found that? I've been looking at the docs, and haven't found any caveats for closed scenes. I thought it would be good for interiors, given it is often used in gaming levels, but this IS all new to me, so I could be mightily wrong

[vlado]

Spherical harmonics are used to bake the illumination from environment lighting, so that afterwards you can quickly change the illumination without recalculating the GI. We are doing short tutorial on that.

Best regards,
Vlado

[Yannick]

I got this from this page:
http://www.spot3d.com/vray/help/maya..._params_gi.htm

[aweidenhammer]

Thanks.

Correct me if you think I'm wrong, but I think he is referring to literally closed scenes, where there is no ambient contribution. My interior scene is not closed, and the ambient contribution is substantial. Thus, I would think that SH could be used. The usefulness however is quite debatable

It only serves as a test scene. I've done other simpler open scenes as well, with the same crashing result when attempting to render with SH as my primary engine. I'm sure it is something simple that I'm not toggling correctly, but in such a case, it should give me an error, and not dump out of maya altogether I'm just wondering what that thing is that I'm not doing right. I suppose I can wait for a short tutorial, but I'm soo close, I can feel it

Andrew

[vlado]

I can get it to crash too, looking into it now.

Best regards,
Vlado

[aweidenhammer]

this was fixed for a while, but I'm getting a crash whenever I try to render SH baking. Even using the tutorial scene.

Andrew

[vlado]

Ok, will check it out.

Best regards,
Vlado

[vlado]

This is fixed now for revision 13973 and later.

Best regards,
Vlado