Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: Tok_Tok on 2017-06-11, 17:59:55

Title: Slow interactive rendering - subsampling
Post by: Tok_Tok on 2017-06-11, 17:59:55
Hi,

I've upgraded to 1.6 and found that the interactive subsampling is not working as near as fast as in the video that's posted on youtube about the new features. For me in 1.6 the screen refreshes every 1 - 1.5 seconds, which is far from realtime. So how is this possible? I running a dual Xeon E5 2699 V3 at 2.1Ghz, might is be because of low single core speed? I have to add that interactive rendering never worked as fast for me as I see in the corona youtube channel videos.
Title: Re: Slow interactive rendering - subsampling
Post by: Juraj on 2017-06-11, 19:42:55
Don't worry, it's never fast for me either :- ) I only use it when rotating single object isolated and even that I have to do in almost empty scene otherwise the interactive will just hang-up for ton of time before starting (regular rendering starts instantly).
Didn't find sub-sampling to help much since when IR is slow, this will further obfuscate the image in buffer by making it unrecognizable during those 2 seconds freeze. Without sub-sampling, I can at least directly compare changes.

Sometime all those hang-ups in bigger scenes make regular hit/quit rendering a lot faster to facilitate iteration for me.

You can check 'force path-tracing' in settings so that IR will always be PT/PT which will avoid the UHD cache re-comp, but to me even that doesn't help. I think 3dsMax itself is at fault of moving all those datas. Sometimes I feel like maybe using all those 8k textures, subdivided surfaces,etc.. isn't best idea because it forbids me from using interactive, but then again, I use Corona purely to be able to render big, complex, high-res scenes. Otherwise I would just use Unreal.
Title: Re: Slow interactive rendering - subsampling
Post by: Tok_Tok on 2017-06-11, 20:33:31
Hm oke well then I must be more patient I guess. But still, the interior scene I'm working on only has around 100.000 poly's and is still slow. I kind of expect a still empty scene like this to render butterly smooth.

Yes working with big scenes, interactive rendering is not really useful. It just takes too long to update and when moving through your scene 3ds max stutters. I would be handy though to have a pause button to temporarily pause the IR to move through your scene and change things instead of quiting the IR and starting it up again.

I think you're right, 3ds max is ofter the bottleneck for handeling big scenes.. although they've done some optimization over the last few versions.

Thanks for your reply.
Title: Re: Slow interactive rendering - subsampling
Post by: Ludvik Koutny on 2017-06-11, 21:11:47
It's most likely UHDcache. If you want performance like on the example videos, you need to check on "Force Path Tracing" in IR section of performance tab as Juraj has pointed out.
Title: Re: Slow interactive rendering - subsampling
Post by: Tok_Tok on 2017-06-12, 19:44:56
Ahh yes that helps, thanks! Juraj as well, I read over it.