Big difference between VFB and RT

[cledus_]

Can someone please help me understand why there is a big difference between VFB and RT.

The first image is the RT & the second is the VFB.

Thanks and have a great weekend!

[3LP]

Yeah I've got that issue nearly every week.
I think it's something related to scale of the fog that is not calculated the same for RT and Production renderer.
I can create a file with my issue as well actually it it will help to troubleshoot..

Stan

[cledus_]

Hi Stan!

That's a good idea. I have attached a scene were I have this problem

[svetlozar.draganov]

It is because of Fog-Color - RT and Production produce different result when this option is activated.
I have noticed that if Fog Bias is set to 100 then both Engines produce the same result - here is one example:


We have this bug into our system.

[cledus_]

Ok then we know. Thanks for the reply

[3LP]

Yeah but having the fog to 100 make the production render like RT.
Isn't it the other way around that you should fix the issue?
Straighten the problem on RT so that it's matching the production render?
It seems that the production render does the right job and RT isn't.

So, I took 5 minutes to show my problem...

Simple scene:
teapot 20cm, shell, domelight...



I guess you noticed that it's quite hard to be able to rely on any of the RT render when it comes to fog color.

Fog at 1 is what I want to achieve (First line), and to have RT working, I need to tweak the fog multiplier but most of the time, it doesn't work and I need to un-tweak it anyway at the end to have it like I want in the production render.

So, generally, I need to go and ether delete the material and recreate the material from scratch, sometimes it fixes it.
Or I need to do all the rest beside the fog and consider doing the fog old school at the end.

I have attached the max file to troubleshoot.

Cheers

Stan

[svetlozar.draganov]

Fix about this issue is already available in the last Nightly Builds - please log in into our Nightly Builds and download one of the last ones , Production and RT result will be the same.

[3LP]

Nice to know,

Thanks,

Will wait for Vray 3 to update though

Stan