Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => [Max] Resolved Bugs => Topic started by: maru on 2013-09-04, 10:55:58

Title: Progressive vs buckets, render time difference
Post by: maru on 2013-09-04, 10:55:58
Again, I'm not sure if it's a bug. Rendered the same region with two setups:

1. Progressive, PTS: 100, passes: 4

2. Bucket, PTS: 100, initial samples: 4


If I understand it correctly, for path tracing this would mean 100 rays per pixel x 4 passes = total 400 samples.
And for buckets, 100 rays sampled 4 times for each pixel = total 400 samples.

I thought the image should look the same and render with same speed. It looks exactly the same, but rendering time is much longer.
Title: Re: Progressive vs buckets, render time difference
Post by: Ondra on 2013-09-04, 11:00:38
you set adaptive steps to 0, right?
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-04, 11:05:30
What is adaptive steps?
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-04, 11:08:25
Another one. Progressive: 400 pts x 1 pass. Bucket: 400 pts x 1 initial sample.

btw, it's  Sep  3 2013 00:00:50
Title: Re: Progressive vs buckets, render time difference
Post by: Ondra on 2013-09-04, 11:51:38
just printscreen the settings ;)
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-04, 12:12:36
here you go
Title: Re: Progressive vs buckets, render time difference
Post by: Ondra on 2013-09-04, 12:37:18
ok, you are comparing something entirely different (adaptive buckets to nonadaptive progressive rendering), so the comparison makes no sense. There is no reason for the two times to be the same
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-04, 12:39:34
How is this adaptive for buckets if there is only one pass?

And if so, then why these two images look the same in terms of quality?
Title: Re: Progressive vs buckets, render time difference
Post by: Ondra on 2013-09-04, 12:48:25
you have "passes" set to 10. I've just tried with 1 and it works as expected. Just send the scene ;)
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-04, 13:19:37
I have passes set to 10 but completing 1/4 of the first pass took much longer than rendering the whole region in progressive mode. I can upload simplified version of this scene later.
Title: Re: Progressive vs buckets, render time difference
Post by: Ondra on 2013-09-04, 13:25:12
do it
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-04, 20:49:15
Ok, looks like HD cache is the cause of this. Without HD cache both images render with exactly the same time. After enabling HD cache, progressive rendering becomes faster and bucket rendering becomes significantly slower.

I added those objects around lights to make the lighting less "uniform" but it also works with regular lights.
Title: Re: Progressive vs buckets, render time difference
Post by: rafpug on 2013-09-04, 23:12:42
Hi maru

I tried the scene while maintaining your configuration
the final image I will be too bright

It 's normal?
Title: Re: Progressive vs buckets, render time difference
Post by: cecofuli on 2013-09-05, 01:28:14
Mmm.. interesting test!
 In fact, usually I prefer bucket (better quality and little adaptive sampling) and I found Bucket mode slow.
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-05, 10:33:32
Hi maru

I tried the scene while maintaining your configuration
the final image I will be too bright

It 's normal?

If you didn't change any settings, this means you have wrong gamma configuration in Max.

Quote from: cecofuli
In fact, usually I prefer bucket (better quality and little adaptive sampling) and I found Bucket mode slow.
Yes, in theory adaptive buckets MUST be more efficient than non-adaptive progressive rendering. But it looks like there is some bug with HD cache which is affects rendering speed in more complex scenes. It's exceptionally visible when you're rendering something for school on a cheap laptop and after whole night you end up with noisy images. ;)
Title: Re: Progressive vs buckets, render time difference
Post by: cecofuli on 2013-09-05, 10:40:52
I'll do some research about this problem ;-)
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-05, 11:06:08
Ok, but remember that I did this test with extreme values just to verify if there is such problem. In normal, more balanced situations this may be unnoticeable.
Title: Re: Progressive vs buckets, render time difference
Post by: rafpug on 2013-09-05, 13:10:16
Hi maru

Mx2014 - default Gamma 2,2

This value is correct?



Title: Re: Progressive vs buckets, render time difference
Post by: rafpug on 2013-09-05, 13:12:38
Default Gamma 2,2
Title: Re: Progressive vs buckets, render time difference
Post by: rafpug on 2013-09-05, 13:20:55
Only if I change the value of the light intensity from 50 to 1.0 mi looks like the render
Title: Re: Progressive vs buckets, render time difference
Post by: rafpug on 2013-09-05, 13:32:55
Visible directly disabled
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-05, 16:00:28
Looks like your lights have different size than mine. What Corona version are you using? Also, check gamma/lut settings.
Title: Re: Progressive vs buckets, render time difference
Post by: Stan_But on 2013-09-05, 18:45:57
Ok, looks like HD cache is the cause of this. Without HD cache both images render with exactly the same time. After enabling HD cache, progressive rendering becomes faster and bucket rendering becomes significantly slower.

I added those objects around lights to make the lighting less "uniform" but it also works with regular lights.

are you tested this with alpha 5 or only with daily build
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-05, 19:35:10
With daily build. Bucket rendering works different it a5. Or at least has different names for parameters. ;)
Title: Re: Progressive vs buckets, render time difference
Post by: rafpug on 2013-09-06, 04:27:36
Looks like your lights have different size than mine. What Corona version are you using? Also, check gamma/lut settings.

Hi maru

Alpha5 of June, the max2014 is only the value Gamma 2,2 (see image)
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-06, 09:51:56
There have been changes done to the lights in daily build, it's probably the cause of your problems...


Keymaster, why are you not writing anything here!!!
Title: Re: Progressive vs buckets, render time difference
Post by: rafpug on 2013-09-06, 12:37:55
Hi maru

Where can I find the input/output gamma in Mx2014?
Title: Re: Progressive vs buckets, render time difference
Post by: Ondra on 2013-09-08, 15:18:30
what does the lights look like in viewport? It is possible that they need to be rescaled when moving between daily builds and A5
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-08, 16:42:21
The lights are not important here. Rafpug has problems because of different Corona version.

What about slow buckets with HD cache?
Title: Re: Progressive vs buckets, render time difference
Post by: rafpug on 2013-09-08, 20:03:08
Hi maru

Unfortunately there is something in the operating system that stops me access to the daily build.
For now, use the v.5 of June

Thanks
Raf
Title: Re: Progressive vs buckets, render time difference
Post by: Ondra on 2013-09-09, 12:05:29
fixed
Title: Re: Progressive vs buckets, render time difference
Post by: maru on 2013-09-09, 12:47:22
Thank you! I want to believe in buckets!