V-Ray Vision - same material different colour

[steve_dimes]

I'm very happy with Vision and a simple animation I've done. But no matter what I do I can't get the ceiling material, which is the same as the white walls, to look correct. It always has an orange tint to it. Image attached. Any suggestions? Thanks.

[nikoleta.garkova]

Hi steve_dimes

How are they appearing on a normal render? Are you sure both ceiling and walls are using exactly the same material? Make sure that there are no reversed faces in the ceiling for example. What if you reset your render settings to their defaults?
Is it possible to strip down the scene and forward it through our contact form so we can investigate what may be going on? Make sure to mention this thread in the email along with exact V-Ray/SketchUp versions. Thanks!

[steve_dimes]

Hi Nikoleta. Attached two images. One is from Vision, the other as a normal render. The ceiling material is the same as the walls and all are front face orientation. I realize they will be different aesthetics. The orange tint in the Vision render is on all horizontal planes viewed from below. What might be causing that? Thanks.

[nikoleta.garkova]

Hi Steve,

Keep in mind that Vison is using approximation, which may be causing such results - what if you use an override material and use it across the project, are you getting any differences? Have you tried enabling the Auto Exposure option in the Vision Settings Panel? If you make a plane and rotate it horizontally/vertically - see if it will behave the same way. Also, are you using sun? - if you move the sun position, see if you will get any differences. Best would be to forward a stripped version of this project so we can check. Thanks!

[konstantin_chaos]

Hi steve_dimes,

The illustrated behavior is actually expected.
The way Vision does it's lighting is quite a bit different compared to V-Ray.
For Vision all the objects in the scene are illuminated directly by the environment - objects are not occluding each other.

In your scene the ceiling and the walls are both illuminated by the Sky texture.
The ceiling is yellowish since it captures more of the environment ground color.
The walls are affected by the more bluish tint of the Sky itself.


In order to improve this we'll have to implement a different Global Illumination evaluation logic.
This is actually on our to-do list but is not a trivial task in a game engine.
One option for us is to enable RTX raytracing for the GI.
It'll affect performance and will be available for NVIDIA RTX GPU owners only but at the same time will improve the lighting quality in a big way.
There are few alternatives that we'll also look into but none of them will give you the accuracy that V-Ray is capable of.

Regards,
Konstantin

[steve_dimes]

Thank you Nikoleta and Konstantin. Vision is a great tool, especially for exterior work and I see how and why it is less than Vantage. I think Vantage is where I need to go for interior real time rendering. All other aspects of Vray are amazing.
Regards
Steve

[vanja_uri]

This answeres my question as well. Are there any workarounds for this? I tried adding a domelight and fliping it 180 degrees. It works.. somewhat. But this makes it pretty unusable on the interios.

[konstantin_chaos]

Hi vanja_uri,

There is currently no elegant workaround for this - one that will not affect your V-Ray rendered scene in a negative way.

However, we have a couple of ideas how to improve interior rendering:

1. We can add an option in the Vision UI that will replace the sky environment light with just an ambient white color. This should make you interiors look better and give you more control.
2. We can implement a Gizmo object that you will place in SU to define an interior volume. And then in Vision, once you enter this volume we can fade to a white environment color.

In the long run, a better global illumination solution should be implemented in Vision.

Konstantin

[vanja_uri]

Ok got it, yea I understand that a better global illumination solution would be the best, but in the meantime a quick fix should be available, since this way it is pretty unusable for interiors due to this bug.

[Jarek88]

Hi all,

I think the problem might be in Color Offset. I dont understand why when changing it in the material it doesnt update in Vision ? Same for the Chaos Cosmos assets.

Thanx !

[konstantin_chaos]

Hi guys,

We have recently released V-Ray 5 for SketchUp, update 2.
In it there is a way to replace the Sky illumination with an ambient color:

• A new Ambient Light Mode is implemented. The new mode can be enabled in the Settings panel. It replaces the project’s indirect lighting and reflection environments with a gray color. The value of this color can exceed 1 and is controlled by the Ambient Light Intensity slider. The new mode can be useful in closed spaces for removing the blue tint coming from the sky

As I mentioned before a proper GI solution is required for better interior lighting.
We will be working on that during the next couple of months and I'll keep you posted on any progress we make.

Regards,
Konstantin