Tutorials on how to render crowds in Iray

gibrril_fa945a6cee

Okay,

The render is finished. (One G3 Character in the scene nothing else.

This is the info the log has on the render (attachment). What am I looking for? (way at the top I added the info the log gave me on startup on my GPU's)

Thanks a lot,

Me

agent unawares

That log file indicates both of your cards are being used during rendering. I see no dump to CPU or memory warnings. (I am on mobile right now though.)

gibrril_fa945a6cee

Okay! I'll take that as a good sign :) Then the question remains... Why can't I render scenes with five or six characters in? Do I need to reduce the resolution then? Is 4050 x 3650 to high?

Thanks a lot,

Me

gibrril_fa945a6cee

Also I do get a lot of warnings in my log when I load figures. Does that impact the rendering and the VRAM usage?

Thanks a lot,

Me

agent unawares

I can't think of a figure load warning that would increase memory use. All my figures throw all kinds of errors about morphs and parameters when I load them.

I don't know why you can't render scenes with more figures, but I would check if your figures are more subdivided at render time than necessary, and look into removing any maps that the scene doesn't need at the distance (like micro details on the skin, displacement when you already have bump, etc). Also maybe delete or add figures in the scene until you hit a point at which it can render in the GPU. That will at least give a baseline for what works.

Iray does not shrink texture files with small renders so the render size should not affect VRAM consumption as far as I know. For a quick check I started renders of a portrait at 300 px and then at 4000 px wide. Memory use was the same across the board for geometry, textures, etc.

gibrril_fa945a6cee

Hi again! I think I found the culprit. I did a testrun with seven HD G3 characters on a 4050 x 3605 resolution with an HDRI background I started rendering at 13:14 hours and let it run for 10.000 itterations. It ran smoothly on my GPU and finished at 14:43 hours. Why did it work this time? I put Render SubD level of all characters to 1. When I load up HD characters that value is put to 3 by default.I have yet to test how many characters I can do if I put that value to 2 or something...

What does that value do and how does it impact a render? Does anybody know?

Also, I was planning on buying a new screen with 4K resolution. I cannot hook up my screen directly to the motherboard. Is the amount of VRAM I lose by having the monitor on my GPU a constant, or does it increase depending on the screen?

Thanks a lot,

Me

agent unawares

Render SubD is how subdivided your figures are at render time. So every step up will increase exponentially geometry memory usage which is why I suggested looking into it. Most characters look okay at 1 but HD details can need higher to show up. I don't know about how monitors affect GPU sorry.

gibrril_fa945a6cee

Thanks for the reply!

Where do I find if my figure will need a SubD higher than 1?

Thanks a lot,

Me

Richard Haseltine

gibrril_fa945a6cee said:

Thanks for the reply!

Where do I find if my figure will need a SubD higher than 1?

Thanks a lot,

Me

If the mesh, especially the outline which can't be helped by shading, looks angular then you probably need a higher level of SubD.

If you are using an HD morph and the detail isn't there (but should be by how closely you are zoomed in) then you probably need a higher level of SubD (though soft lighting can also obscure detail).

3 or 4 should be the highest level required for most products, very few HD morphs will use addititional levels of division.

gibrril_fa945a6cee

Thanks!

Is there a way to calculate how much more memory each SubD stepwill take? So I don't have to go through trial and error in order to find out?

Thanks a lot,

Me

agent unawares

What I would do: start a render with only one figure at 0 SubD, let it load the scene into the GPU and then cancel the render. The log file will state geometry size. Repeat for higher SubD levels and you will have a quick reference for exactly how much memory one figure at a given SubD level takes up.

gibrril_fa945a6cee

Thanks for the tip!

gibrril_fa945a6cee

As for the other question that I lost track of myself too :)

If I buy a "heavier" monitor with 4K resolution, will that impact the amount of VRAM that is "lost" to render with?

Thanks a lot,

Me