Need Help With Render Time for Environmental Scenes
ravvenkitsune
Posts: 77
Although I can do high-quality renders of figures with no backgrounds, trying to render an environment takes forever. Tried to render a shot of the KA Poseidon Station (Iray) with no extra lights or figures last night, this morning it was at 21 hours and 24% complete. I think I have a decent computer, so I'm confused why this is so difficult. I'm doing renders at a reasonably large size as I need them for high-resolution artwork.
My computer:
Windows 10 Home
Intel(R) Core(TM) i5-3570 CPU @ 3.40GHz (4 CPUs), ~3.8GHz
Memory: 16384MB RAM
DirectX Version: DirectX 12
NVIDIA GeForce GTX 1070, 16318 MB
Render Settings attached.
Thanks - I would appreciate any help as this is driving me nuts. :)
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Comments
The reason why it takes longer with actual backgrounds (non-HDRI background) is because of the reflections and such. When there is no background objects like walls etc, the light is just hitting the single figure from the HDRI map or light not reflecting on other objects. You're system is fine, but it will still take some time to render when having full backgrounds such as rooms, indoors, etc. Having two supported graphic cards will increase performance.
So 20+ hours and still nowhere near complete is not excessive? I may cry. :D This is my work computer, so I don't have a machine that I can reserve for rendering over a period of days.
It could be that the scene is too big for your graphics card especially as you say you are rendering at a large size; some environments take up a lot of memory
Trust me, I cry too, lol! I can render a G3 figure with just a HDRI very quickly, but when I load an indoor scene... :( Other things that will be slow is mesh lights (very slow). I never use those and remove them from scenes. What I do to get the best possible speed is remove all the walls that are not seen and I also remove the ceiling, it won't be the most natural way of lighting, but it will speed things up. Other than that, you need more graphic cards. Iray's speed is based on cuda cores if rendering in GPU mode
EDIT: Sorry, I just registered the near 24 hours that you mentioned. Do you have your GPU selected in the advanced settings? Over 20 hours does seem quite a bit long with your card. What kind of scene are you rendering? You may be on CPU mode.
Interested in - if you find a way to reduce the render time what method you end up using...
The log file should give info on how much memory is being used on textures, lights etc.
If it is the textures taking too much memory there's a script to reduce the sizes temporarily http://www.daz3d.com/forums/discussion/137161/reduce-texture-sizes-easily-with-this-script
You could try iray section planes too
Thank you so much for the help, I really appreciate it! I'm rendering one room from this: http://www.daz3d.com/poseidon-station (The room with the table, with the benches removed.) It would be nice to run a second card, but I would think I'd need another GTX 1070 which would be expensive just for rendering. I'll try removing the sections that I'm not using - thanks for the tip, as I didn't realise that offscreen stuff would affect the render. Noob here, as if you couldn't tell. :)
No problem. Do you have any figures in there as well, or is it just the room. I'm going to render a similar scene and with the same resolution you have and with all walls and the ceiling on, and I'll see what I get for rendering time. The last time I did that it only took about an hour, but that was at 1920 by 1080 resolution.
Thank you for that, I'll try the script and read up on section planes as well. I'll also try with a different scene, as this one isn't modular (if that is the right word?). I can't remove the sections that I'm not using without deleting the entire thing.
Thank you so much. It's just the room itself. I don't seem to be able to remove any of the sections that I'm not using, as the whole thing disappears even if I just have that bit selected.
If they are separate bones try selecting them all and then clicking the Visible button in Parameters, or for a small number of items click the eye icon next to each in the Scene pane.
Thanks! I can turn off visibility even though I can't delete them, I'll try that. Again, new to all of this. :)
I did a render test with your resolution settings on a similar scene for about 15 minutes, and it was still at 0. I guess It will take a very long at that resolution with everything enclosed and even longer if there are mesh lights in there. Turning off the metallic setting for all objects in the surfact tab will also speed things up if they are using iray material because of less reflection, but it won't look as pretty or natural for objects that need it.
Very much appreciated. :) I think at least part of the problem lies with this particular scene, as I bought another ( http://www.daz3d.com/sci-fi-corridor-a ) and tried it at the same size/parameters. Right now it's at 45% after 3 hours, 45 minutes - which is more in line with what I would expect.
Thank you everyone for all your help!
No problem, glad it's working better!