V-Ray Render Optimization - an in-depth Guide (call for Before/Afters)

[RockinAkin]

What settings should we use for fog? High/80 Subdivs?

Yeah, fog belongs in the DMC sampler camp, so higher Subdivs will help keep your Image Sampler under control.

Here's a thread with some good info:
http://forums.chaosgroup.com/showthr...-tips&p=629574

[3LP]

Ok 14+ camera! That would be a little long to fake ligthing for each one. But if your deadline is near you may have no other choice but keep the hdr for reflection only and fake the lighting with rectangular vray light etc. (no sun/sky cause they are also too render intensicve). That solution would take less time than rendering everything as is. I use circular faloff map in the vray rectangular light to fake the sun. Or even a standard directional light if i need hard shadows.

One thing I would also try for your trees, bushes and foliage (that would work very well at least for this particular render) is to render a HDR of your outside 3D environment. You use a spherical camera and place it at the center of you environment and you render a spherical hdr that you can then use in place of you 3D trees and foliage for all your render.

I guess you are using Reinhard for your color mapping type. Did you try reinhard burn at 0.05?

as for the settings I would definitely try adaptative image sample min 2 and max 16 using dmc sampler thresh checked. then global dmc: aa 0.85; noise threshold 0.008, global mult 32, min sample 8. then everything in the scene at 8, except for all the material where we see noise, I would put their ref samplings to 64 and if you use light cache put it at 3000 subdivs. and if you see noise in the light, up the sample of this light to 32.

You do renders with global subdiv at 32? wow, that seems so high, even with everything at 8, but I'll definitely try that out

Is that old fashion way of having smaller hdri fot ibl still actual? I though that was old technique used 10 years ago.
The down side if this is that you will lose any hard shadows if you had some with the high ress hdri.

Stan

[jstrob]

You do renders with global subdiv at 32? wow, that seems so high, even with everything at 8, but I'll definitely try that out

Is that old fashion way of having smaller hdri fot ibl still actual? I though that was old technique used 10 years ago.
The down side if this is that you will lose any hard shadows if you had some with the high ress hdri.

Stan

Any trick to use less memory is always good as long as it doesn't change the end result too much. Cause even if we are ten years later we now use much higher resolution camera and much larger image but we still need to optimize as much as we can. That sais, I don't even use IBL. I think I would need it only if I have to reproduce a very complex lighting sretup like a CG timesquare for example (that's why when I went to NYC last time I took a few 360 HDRI ) with lots of differents lights and many different colors. But most of the time I prefer to create my ligthing setup with vray lights and directional standard lights. it's a bit longer to setup but so much faster to render.

[snivlem]

[ATTACH=CONFIG]21402[/ATTACH][ATTACH=CONFIG]21403[/ATTACH][ATTACH=CONFIG]21404[/ATTACH][ATTACH=CONFIG]21405[/ATTACH][ATTACH=CONFIG]21406[/ATTACH]

Here are the passes of the scene. The same lighting could be achieved with a sun/sky solution, but this scene is huge and there are 14+ cameras to render of various spaces, so using an HDR really speeds up the lighting process. The outside is all 3D with high poly trees, bushes, grass etc which definitely have a huge impact on lighting and render times. I suppose the AA is set too high since it never reaches anything nearly the 25 max. Using lower AA with even higher subdivs for mats/lights and a noise threshold of 0.003 gave the same result with similar render times.

It's probably too late now in your project, but your high poly 3D trees will slaughter the render time, I'd keep the HDRI and high quality light but ditch the 3D Trees and in a background in post.

Since you have 14 cameras though, a probably better solution would have been to map a single image plane with a texture on it and self illumination as a background.