Chaos Corona Forum

Chaos Corona for 3ds Max => [Max] Bug Reporting => Topic started by: ynotsop on 2018-05-22, 22:02:33

Title: Exposure resets every time I edit Corona Sky or Corona Sun
Post by: ynotsop on 2018-05-22, 22:02:33
Not sure if I am doing something wrong or if this issue has already been resolved. I have a scene with an object and a backplate set up. I need to match the sun/object's exposure to the backplate. I created Corona Sun and added the skylight map into corona environment slot. My object immediately becomes overexposed. If I change the exposure in Corona render window to -6.0 I get a fairly normal looking object with appropriate exposure. (like this person here https://www.youtube.com/watch?v=IZSkPzeljJg (https://www.youtube.com/watch?v=IZSkPzeljJg))

The first problem is that my backplate (obviously) also changes its exposure to -6.0 and now I can't match the two exposures (the object and the backplate).

The second problem is that after I change the exposure to -6.0 and then edit any kind of parameter either in Corona Sky or in the Corona Skylight map the exposure of my object jumps back to it's original overexposed value. I then have to set my global exposure to -12 to get the correct exposure again and so forth. It's impossible to work like this.

I've tried using Corona Output to regulate the exposure of the Skylight map but I get completely different and incorrect exposure.

If I use 3ds Max's sun system everything seems to work fine.

I hope someone can help me with this issue. Thank you so much.
Title: Re: Exposure resets every time I edit Corona Sky or Corona Sun
Post by: ynotsop on 2018-05-23, 09:41:41
With regards to the overexposure problem it seems like there was some sort of a glitch. I've tried the same setup on another simple scene and there was no exposure reset. When I opened my working file today everything is working as it should, the exposure is not resetting.

About my first problem. Is there any way to set up Corona or/with 3ds Max in a way that I can adjust the exposure of my object without affecting the exposure of the backplate?
Title: Re: Exposure resets every time I edit Corona Sky or Corona Sun
Post by: romullus on 2018-05-23, 11:15:57
Yes, you need to plug your backplate into CoronaOutput (1.7) or CoronaTonemapControl (2.0+) and uncheck affect by tonemapping.
Title: Re: Exposure resets every time I edit Corona Sky or Corona Sun
Post by: ynotsop on 2018-05-23, 14:10:36
Thank you!
Title: Re: Exposure resets every time I edit Corona Sky or Corona Sun
Post by: ynotsop on 2018-05-23, 14:21:55
So I have the "Affected by Corona VFB.." unchecked in the output map of my backplate. However if I increase or decrease the exposure in Camera:Post processing the backplate's exposure is still being affected. Why is this happening?
Title: Re: Exposure resets every time I edit Corona Sky or Corona Sun
Post by: TomG on 2018-05-23, 14:27:06
The notes in the tooltips should have all the info - while exposure is protected, it is only protected at render time. If you change the exposure, you need to re-render (or restart IR).
Title: Re: Exposure resets every time I edit Corona Sky or Corona Sun
Post by: ynotsop on 2018-05-26, 23:06:52
It seems like the exposure of the backplate image resets once I click on something random. I guess this sends Corona interactive the signal to update the render and thus reset the exposure. So everything is working as it should.
Title: Re: Exposure resets every time I edit Corona Sky or Corona Sun
Post by: maru on 2018-07-09, 13:39:15
It seems like the exposure of the backplate image resets once I click on something random. I guess this sends Corona interactive the signal to update the render and thus reset the exposure. So everything is working as it should.
Yes, exactly, IR has to be reset for the expected result to appear.