Rendertime Difference when Colormapping_Gamma On

[hugojackson18]

Hey

I've noticed a massive difference in render time between when I start the render with Colormapping_Gamma on 2.2 or on 1.
I'm not using Corona's own colormapping as I'm using Maya_2015 new color management system and I'm using a Custom LUT, but when I put the Colormapping_Gamma at 1, it is much much longer than when it is on 2.2, and I can see that it's sending a LOT more samples when it's on 2.2

Any reason for this? I've read somewhere that brighter images were longer to render, so I was wondering why it was the opposite here.

Here's a couple of images

You can see as well that if I put the gamma back to 1 AFTER the render is complete, the image is identical.

Render started with Gamma at 1 (ColorManagement ON)


Render started with Gamma at 2.2 then reverted to 1 after the render completed (ColorManagement ON)


Gamma at 2.2 with ColorManagement ON


Gamma at 2.2 with ColorManagement OFF


I find it a bit obscure, so I thought there might be an issue somewhere. I don't mind using Corona's Colormapping but I'd much rather using my custom LUT.

If anyone knows why this is happening, as it's a really stranger behaviour to me.

[hugojackson18]

EVEN WEIRDER

When I start the render with Gamma at 2.2 AND Maya's Color Management is OFF from the start, it's even quicker to render!!!



I was looking for render times optimisation, that might be the fastest i found!

[hugojackson18]

It would be great as well if someone could write a detailed explanation of what this part of the render settings exactly do.

(I'm talking about the bottom part of it, with all the samples options.)


I know the manual is outdated (this part is not even in the manual) but if someone could tell me, I could actually try to update the manual with some of the infos I found here and there.

Thanks!

[romullus]

You can go there and look into performance rollout: https://corona-renderer.com/doc/

[maru]

It would be great as well if someone could write a detailed explanation of what this part of the render settings exactly do.

(I'm talking about the bottom part of it, with all the samples options.)


I know the manual is outdated (this part is not even in the manual) but if someone could tell me, I could actually try to update the manual with some of the infos I found here and there.

Thanks!

I guess Corona settings work the same for different software versions so you can read about most parameters in our helpdesk (it is currentlt 3ds Max-only):
https://coronarenderer.freshdesk.com/support/solutions/folders/5000156713

[hugojackson18]

Cool thanks guys for the docs!

[haggi]

I'll have a closer look at the gamma differences. Seems really strange to me.

[Ludvik Koutny]

Hmm, this could be due to the Maya's native VFB perhaps spending more CPU time on redrawing and gamma correcting than Corona does on rendering itself?