VRayEnvironmentFog and scene scale creating problems...

[jstrob]

When I change the scale of my scene the VRayEnvironmentFog becomes very dark and even disapear in some areas...

I am using a geometry gizmo in my scene.

So is there any way to scale a scene and avoid these problems?

See pictures belows (I want my fog to be green but when scaling it becomes black...):
near default max scale


scaled down 0.1x scale


2x scale


3x scale

[jstrob]

I noticed the problem seems only to exist with geometry objects as gizmos... When I use athmospheric gizmo, just the opacity is changing with scaling which is a bit annoying but still possible to correct by adjusting the distance in the fog settings. But with geometry object, even if we adjust the distance setting, the fog becomes totally black and I can't find a way to make it the correct color...

[svetlozar.draganov]

This is actually not an issue - 3DSMax and Vray work in scale units and this is normal behaviour.
To Illustrate this issue follow this example.
Create two simple spheres with radius 10cm/inch (not instances) - now scale one sphere by 1000 percent.
Now you have two spheres - the second one is 10 times bigger than the first one.
But look what's happening in the radius parameter - they still have the same radius = 10cm/inch
Because of this - it is not recommended to scale gizmo's or any type of object with parametric input , because they don't work as you expect after you scale them !

If you want to scale your scene you have to do it with Rescale Word Units from Utilities Panel "More" !
Using this feature you can scale your scene down or up , and the fog will look the same way !

[jstrob]

Hi, thank you for your answer,

I know what you mean, but this is not normal behaviour.

If I use VRayEnvironmentFog with a standard gizmo, the color stays the same, but if I use a geometry gizmo it becomes black.

What you are talking is only about density. I can adjust the density while scaling, but the color is not supposed to change and if it does, we just can't adjust it making it impossible to scale a fog element in a scene thus preventing from using it in most of my production.

Anyway the way you are talking about for scaling a scene does not apply when I have to scale only some elements in my scene, which I always have to do for all my projects cause there are always elements like FX or elements from other people or other softwares that are not to the same scale.

[vlado]

Can you get me a scene for this? I can quite figure out what's happening from the images alone.

Best regards,
Vlado

[jstrob]

Here it is:
http://www.strob.net/vray/testFog_scaleProblem_001.max

You have to scale down the Point001 helper to normally see the green fog, but when scaled à 100 percent, the fog is black.

I just installed the latest nightly builld and now when scaled down to 10%, the fog is just not rendering at all.

I started a scene from scratch with the new build (with no light this time though) and the fog still render black. But I noticed when there is not light at all, the fog is green.

[vlado]

Thanks, I can reproduce the issue; looking into it now.

Best regards,
Vlado

[jstrob]

I noticed the fog is green when I erase all the lights

With vray light, the fog is the right color too. the bug seems to be with standard max lights

[jstrob]

Cool! Chaosgroup got this fixed in latest nightly build. Thank you so much for the strong users support!