Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] General Discussion => Topic started by: romullus on 2017-01-26, 16:02:57

Title: Bloom and glare overhead
Post by: romullus on 2017-01-26, 16:02:57

How much penalty in render time do we get if leaving bloom and glare turned on during rendering? If it's more than couple percents, maybe it's worth to keep it off and turn it on only after rendering is finished?

Title: Re: Bloom and glare overhead
Post by: Frood on 2017-01-26, 16:10:38

I was asking myself the same recently. Though I have no data, it feels to be quite some amount.

I wonder if B+G is calculated periodically in the following situations:

- Render via Backburner
- Minimized Max
- Minimized cVFB

Or is it just linked to cVFB refresh time?

Good Luck

Title: Re: Bloom and glare overhead
Post by: Ondra on 2017-01-26, 21:02:12

while the overhead should be small enough, there is no reason ever to calculate it on DR slaves. I have disabled it for corona DR

Title: Re: Bloom and glare overhead
Post by: Cheesemsmsm on 2017-01-27, 05:31:30

If I turned it off, I always forget to turn it on before saving. And then I realized that I forgot to turn it on when I open the file in photoshop.
I have to re-open the scene, resume render, waiting for calculating GI and denosing, turn on bloom and glare and save... It takes ages for large scenes.

so I always turn it on lol

Title: Re: Bloom and glare overhead
Post by: martinsik on 2017-01-27, 10:01:11

In the worst case scenario (short rendering with high resolution) the computation of bloom and glare may completely overtake 1 logical core.
So if you have 16 logical cores, you may loose 6% of rendering power (or even twice more if you have less physical cores and use hyperthreading).

On the other hand, if you render for long time and don't change the bloom and glare parameters during rendering, the period of updating bloom and glare will get longer and longer up to 30 seconds,
and thus the overhead will be minimal.

Title: Re: Bloom and glare overhead
Post by: romullus on 2017-01-27, 10:32:02

Thanks for the answer. Long time rendering is what i'm interesting about.

Title: Re: Bloom and glare overhead
Post by: martinsik on 2017-01-27, 10:33:03

Quote from: Frood on 2017-01-26, 16:10:38

I was asking myself the same recently. Though I have no data, it feels to be quite some amount.

I wonder if B+G is calculated periodically in the following situations:

- Render via Backburner
- Minimized Max
- Minimized cVFB

Or is it just linked to cVFB refresh time?

Good Luck

If cVFG or Max is minimized, bloom and glare is not updated.
If cVFG is active (not minimized), bloom and glare is refreshed, but not as often as cVFB itself.

Title: Re: Bloom and glare overhead
Post by: Frood on 2017-01-27, 12:43:02

Thanks for the detailed insights - calming to know about that long run behaviour indeed because it affects BB jobs as well.

Good Luck

Title: Re: Bloom and glare overhead
Post by: Nejc Kilar on 2017-01-27, 15:08:00

Good to know! I would presume these numbers are with the 1.6 daily (i.e the speed has been further improved) and not with 1.5?

Title: Re: Bloom and glare overhead
Post by: Saif on 2017-01-28, 21:01:29

What about if you rendering an animation, if you disabled it you will get faster render, but with no bloom and glare ?

Title: Re: Bloom and glare overhead
Post by: romullus on 2017-01-28, 21:20:04

Well, with animations you have no choice, it's either on or off, unless you're willing to sit in front of your pc and constantly turn on and off B&G while frames progresses :]

Title: Re: Bloom and glare overhead
Post by: Saif on 2017-01-28, 21:48:22

Sounds fun