VrayNext VFB bug/region render with auto exposure enabled

V-Ray V-Ray for 3ds Max Issues
1

Hi everyone,

when doing a region render on top of an existing render inside the VFB with auto exposure enabled,
the region render doesn’t match the initial render in terms of brightness/contrast.

Plus, with each additional region render on top of the existing region and render,
the newly generated region render looks again different compared to the renders done before.

Happens in bucket and progressive mode.
The only way to prevent this behavior
is by switching off the auto exposure before doing a region render.
Is this behavior intended?

I did a search in the forum, but couldn’t find a post about this issue.

scene file attached
tested in max2016 and max2019

Thanks
Jochen

initial rendering with auto exposure enabled.jpg
initial rendering with auto exposure enabled.jpg1861×1194 189 KB

1st iteration with region render on top. no settings have changed compared to the initial rendering.jpg
1st iteration with region render on top. no settings have changed compared to the initial rendering.jpg1862×1195 194 KB

2nd iteration with region render on top. another shift in the way, the region render looks compared to the initial as well as the 1st iteration. again, no settings have changed compared to the initial rendering.jpg
2nd iteration with region render on top. another shift in the way, the region render looks compared to the initial as well as the 1st iteration. again, no settings have changed compared to the initial rendering.jpg1853×1175 192 KB

VFB region render bug_vrayNext_max2016.max.zip (59.6 KB)

2

Hi Jochen,

Please check this thread - V-Ray Next: Auto Exposure and Render Region - Issues - Chaos Forum

3

Hi Peter,
thank you for pointing me to the correct thread.

best,
jochen