Lighting is Darker But All Settings are the Same

[elias_glasch]

I am getting a weird issue where my lighting is changing however I have not changed any settings. I locked down the lighting around version 15 of this maya scene and the renders look the same, until they mysteriously get darker in version 33. The only difference between these two scenes is that I have been tweaking the xgen hair and importing geo. When I compare the darker scene to versions of the scene that render correctly, I do not see any difference in the lights, materials or render settings. Is it possible that there is something else effecting the overall lighting of my scene?

Once when I was having this issue, I deleted the vraySettings in the outliner and the lighting was good again. However this time, that is not a solution. This issue has happened to me during many different projects in the past and I am not sure what I am doing in between good and bad renders to make this happen.

In the screenshot, you can see that the cyc is lighter on the left (good) side. The entire scene is darker in the latest renders (not just the cyc) You can also see my render settings if that helps. The settings are 100% identical for good and bad scenes.

[elias_glasch]

I was able to get around this problem by exporting the lights from a previous version of the scene and importing them into the latest. I'm still curious why the scene was darker after no obvious changes, but this fix will work for now.

[Karol.Osinski]

It used to happen very often too me when I accidentally moved my camera too close to some object / went inside a wall or something during IPR rendering, suddenly everything went dark, the fastest solution was to boost the camera ISO.