Keep background white

[furyferret]

Hey, I hope someone can help. Is there a way to alter the white balance/exposure etc in the frame buffer without it affecting the environment background colour? I want to render a product shot on a perfect white background but at the moment it goes grey when I alter the contrast and exposure settings. Thanks!

[romullus]

Create CoronaOutput map, make sure that affected by color mapping is unselected, plug into input slot CoronaColor map, set colour as desired. Now plug CoronaOutput to enviroment override and you're done.

[furyferret]

Great, thanks!

[maru]

We have a solution for this, too. :)
https://coronarenderer.freshdesk.com/support/solutions/articles/5000522247

[ce89]

I have tried using this method with a hdri map, but with no luck. Maru's link works very well with smaller objects requiring a CoronaLight material, but for a main light source I cannot get this to work. I have tried putting a VrayHDRI map into a CoronaOutput map and flicking between "Affected by Colour mapping". This seems to alter the whole illumination of the scene and not just the visual appearance of background as I thought would happen (i.e not getting a blown out background).

In vray you can use the dome dome light for lighting and a separate hdri loaded in the environment slot as your background which gave you control over the backplate to stop it blowing out. Very useful.

Not sure if this is possible in Corona?

[romullus]

Yes, this is perfectly possible to do in Corona too. Look for a enviromental overrides in render settings.

[maru]

As Romullus said:
-environment lighting will be generated by the map/color used in 3ds Max environment settings OR F10>scene>scene environment>use Corona
-directly visible background will be taken from the same place OR from F10>scene>scene environment>environment overrides
Hope it's clear or it will get clear in practice. :)

[ce89]

romullus, maru,

That's great. Thank you for clearing that up. Makes complete sense now.