VRay settings for big renderings

[NicoC]

Hello

We're asked by a client to provide several quite big renderings for print, about 10 000 x 10 000 px. Since we generally deliver images 2500 or 3000 px large, I must admitt I'm not very confident about tweaking settings for such hires images ... do you guys have some tricks to optimize AA, IrrMap and LC settings to get a good quality / rendertime ratio ? all the more that the scene has reflections / refractions / area shadows everywhere, I'm a bit worried about the rendertimes

Thanks in advance for any help !

Regards.

[Shimakaze]

As usual there's not really any one way to set up a render, but as for general tips: You can generally get away with lower settings for irradiance maps for large pictures. Watch RAM usage so you don't overdo it. All tips from here are still valid http://www.cggallery.com/tutorials/vray_optimization/. In order to experiment more quickly, set the render output to the final render size and use region render on important sections of the picture to quickly preview your settings. When you're ready to render you might save some RAM by disabling the memory frame buffer, enabling generate preview, and render directly to an EXR or vrimg file.

[glorybound]

Also, you can up size it in post, too.

[Pixelcon]

http://docs.chaosgroup.com/display/V...y+Large+Images

Hello

We're asked by a client to provide several quite big renderings for print, about 10 000 x 10 000 px. Since we generally deliver images 2500 or 3000 px large, I must admitt I'm not very confident about tweaking settings for such hires images ... do you guys have some tricks to optimize AA, IrrMap and LC settings to get a good quality / rendertime ratio ? all the more that the scene has reflections / refractions / area shadows everywhere, I'm a bit worried about the rendertimes

Thanks in advance for any help !

Regards.

[NicoC]

Hello,

Yes, sure, but not in great proportions ... I mean, we wo'nt render at 5000 to upsize to 10000

[NicoC]

http://docs.chaosgroup.com/display/V...y+Large+Images

Thanks for the link Pixelcon I remembered half the informations about rendering to raw image, so it's a great reminder, thks !

[Morne]

Hello,

Yes, sure, but not in great proportions ... I mean, we wo'nt render at 5000 to upsize to 10000

Try this: (these were enlarged 400%)
http://www.benvista.com/photozoompro/examples

[NicoC]

Try this: (these were enlarged 400%)
http://www.benvista.com/photozoompro/examples

Nice ! I didn't know this one - thks

[Deflaminis]

I've spent the better part of my lighting/rendering career doing posters for various companies. Rendering huge isn't that bad as long as you realize that noise at 300 dpi looks a bit different than at 72 dpi. You can get away with quite a bit more than usual because at that res it's a huge poster and people are likely standing 5-10+ feet away from it.

Solidrocks is pretty good at getting a starting point for huge renders I've found, though I don't really use it anymore. It's pretty good at setting those little values in IR map like edge distance that time doesn't permit many of us to get to. If you don't have access it's not a huge deal, but for huge renders I do dabble in there a bit.

Regarding GI, the one thing that I see that matters most is every time you double your res, you can move the min/max settings for the IRmap down -1. Huge renders I end up at -6, -3 a lot and everything seems fine.

Another thing to note is at that res, they're probably looking to print a poster. A bit of noise actually helps in a large print like that from 10 feet (where most people will be) where the noise helps create detail that isn't there from a distance.

I've had some luck on vray 2 with generating my gi maps at half the intended res, locking them in, and then going up.

As far as the image AA goes, you can find the sweet spot easily if you turn off reflections and glossy effects in the globals first. A samplerate render element helps to preview the edges and at a huge res of 30k x 30k orange coloring can even work out pretty well at 300 dpi.

On some systems they will sort of hang/crash in the middle of a render, and disabling the render buffer window can help quite a bit here. I'm not sure why but it works.

Depending on your machine, you're going to run into RAM problems, and setting memory to dynamic and getting the right dynamic memory limits will really help out here. I usually take my system ram and subtract 4 gb. For 10k that should be fine, but at say 30k that can not even be enough and you'll have to turn off memory mangement altogether and render straight to the disk with .vrimg. (Can be a pain to convert those but it's necessary.)

[NicoC]

Hello Deflaminis,

Thanks a lot for your explanations ! that definitely gives me some more clues
We've ran the 3 first images over night, and surprisingly, rendertime / quality ratio is acceptable: between 3h - 3h30 with 4 machines involved in DR rendering. I've tested with SR to see what settings it suggested, and tweaked a bit from there

Thanks a lot for your additional suggestions !

Cheers.