Mental Ray Area Lights

[yourfather]

Hello everyone.

 

Quick question. I've been searching the web for a solution to the "known" Mental Ray Area Light issue.

 

The issue is that the Area light renders a Hot Spot and not evenly distributed light the size of the Area Light.

 

Any other ways to get an evenly distributed light source with no hotspots and using mental ray?

[marius e]

That also really frustrates me, wish they could fix that. Dont know of any sollution to the problem....

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Solution is to use light portals. In it's advanced parameters rollout for color source choose Custom and plug in a Kelvin temperature color map. Set that map settings in material editor. Map intensity is in lux.

[CJI]

Dario's solution is the only one i'm aware of that semi works. Its not a perfect distribution in my experience but its the closest you will get in MR. It frustrating to say the least!

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Its not a perfect distribution in my experience but its the closest you will get in MR.

 

Exactly, if placed close enough even light portal will give you a hot spot.

You could try a plane with self illuminated material. It used to be hard to render (required high FG and was grainy), but maybe it's better now, with unified sampling. Didn't test it.

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So...

- 3×3m closed room, one plane with self illuminated material

- average FG settings (point density 0.5; rays per point 250; diffuse bounces 3)

- nothing special for unified (min/max 1/200; quality 2; cutoff 0.01)

Looks like it could be useful.

 

http://img13.imageshack.us/img13/7390/fyut.png

[yourfather]

Dario, I want to thank you for your time. I really hope i can give back to these boards some day. Thank you. I will try self illumination.

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You're welcome

[marius e]

So...

- 3×3m closed room, one plane with self illuminated material

- average FG settings (point density 0.5; rays per point 250; diffuse bounces 3)

- nothing special for unified (min/max 1/200; quality 2; cutoff 0.01)

Looks like it could be useful.

 

http://img13.imageshack.us/img13/7390/fyut.png

 

Are you only using a self illum material and a plane, no lighting?

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Are you only using a self illum material and a plane, no lighting?

 

Exactly, just one self illum plane.

[marius e]

so where does the 'unified' come in?

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so where does the 'unified' come in?

 

Smarter sampling of everything, no more grain, better results with shorter render times. It's a shame there is no "how to unified" with max 2014. If you don't go out and look for yourself, you're probably not using it right. I've been using it for some time now, before it was exposed in max UI (with Thorsten script), and there is enough info on it out there if one wants it.

But, long story short: where ever you see a sample setting, set it's value to one. Glossy samples in materials, shadow samples in ligth, samples in ambient occlusion, etc... All to one. Unified takes care of the rest (lights, i.e. shadows could still need 2 or 4 in some cases).

That's why you can get away with crazy settings like 200 or 300 for max value.

 

http://elementalray.wordpress.com/2011/11/30/unified-sampling-visually-for-the-artist/ (it's got even better since this post, it samples more in light areas, less in dark)

http://www.infinity-vision.de/blog/render_optimizer