Exposure resets every time I edit Corona Sky or Corona Sun

Corona Corona for 3ds Max Issues
1

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)

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.

2

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?

3

Yes, you need to plug your backplate into CoronaOutput (1.7) or CoronaTonemapControl (2.0+) and uncheck affect by tonemapping.

4

Thank you!

5

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?

6

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).

7

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.

8

Yes, exactly, IR has to be reset for the expected result to appear.