How does mental ray handle heavy geometry scenes ?

[paraganek]

Hi Mental Ray gurus,

I am in a process of comparing Vray and Mental Ray renderers and I am trying to find out how good (fast) Mental Ray is in handling and rendering really heavy geometry scenes.
In Vray we have been rendering large exterior scenes with 3D high-poly trees in full GI using vray proxies. A typical scene is about 500 trees each about 400,000 polygons which makes a 200 million poly scene.
Does Mental Ray have anything comparable to Vray proxies to be able to render such high poly scenes? Is there maybe any other approach in mental Ray to handle such a heavy geometry?

Please share your knowledge :-)
Thanks

[manta]

Nope, it will crash, vray proxy's are the greatest invention ever, I don't think any other renderer has something similar, that will change I'm sure...

[psv1]

use placeholder objects.....

F1 in max should bring some light too on that matter

[AJLynn]

You've got Vray handling 200 million polys? I'm impressed. But maybe there's a better way to handle your trees - 400k is a heck of a lot, unless they're your subject matter and you're doing close-ups of them.

The most complex model I've worked on recently has all of downtown Boston, and that's 429k faces.

I know mr has an Instance function but I don't know how/if that works well with Max. And mr's GI calc time is pretty much geometry independent, so if you can get it to load you should be able to render it.

[Christopher Nichols]

dude... using instancing I have been able to render a few BILLION polies in Vray using only 256k of ram.



if you look at the computer and the version of Vray you will see that it was a LONG time ago.

[manta]

Ya, I was gonna say thats nothing also (200 million) I've rendered 15,000 high poly trees (200,000 polys each) and my computer didn't even flinch, took like 4 minutes to render with GI, love proxys...to tell the truth I don't know what the actual limit is, I never reached it.

[AJLynn]

Wow. I had no idea. I'm going to have to try this.

Does it work well with large models (say, a large city) or just with instancing? I've been fighting with a model of downtown Boston for months...

[manta]

yes, you can convert large sections of your city into vray proxy meshes, and then just import them into your scene...

[pradipta]

It's an very important aspect of vRay rendering. Do you have a proper article on vRay proxy and it's use? I have been looking for it for a long time. would be grateful to you for helping me out

[Karlfucious]

Acually Mental Ray will render any size scene without problems when you use large BSP. It renders about 15% slower than regular bsp but it should be able to handle billions of polys without any crashes.