Override Specific Materials in Rhino Vray to Prevent Unwanted Colour Reflections

Rendering V-Ray
1

Hi there, I am learning how to use Rhino Vray for my uni assignments and I stumbled upon a problem of having unwanted shades of reflected color onto my surfaces/materials where they are supposed to be non reflective.

Essentially I want to override some surfaces/layers so that that they are truly non-reflective. The images below show the examples where unless I add a grey base in between the timber walls and grass field, the timber walls will be covered in green tint due to the grass even though I did not insert any ‘reflective’ layer on either the grass/wood material. In reality timber materials are not reflective and I want to illustrate that in my renderings. Another example below is me trying to showcase a concrete grey wall and timber floors but the effect is spoiled again by the reflected color from the timber.

All vray settings are in default. What should I do in order to prevent it from happening? I read that other softwares like 3dmax has the option to overide such materials, but I cannot seem to find one other than the general override option in the global switches section.

Thanks.

2
  1. The easiest way is this: vray options - under indirect illumination tab - decrease saturation value until the spot vanishes.

I remind you that 1 is the physically correct value.

3

Also, if you want it to look real (hello?) then leave all values at their physically accurate settings. Take a look around and you will notice this effect everywhere.

The reason that it’s so noticeable in your scene is that you have an incomplete set-up & artificially simplified environment. Keep adding stuff and it shouldn’t be a an issue.

4

Thank you for your advise. It helped a lot.

5

It’s true that some materials are reflective, but as the examples above showed, sometimes there are materials that are not reflective in nature, like timber to grass.

Thanks for the heads-up that by adding more stuff it will get better, never considered that before.

6

To be technically correct, ALL objects reflect light. Otherwise, you cannot see them. If you can see them, then the light that hit them will pick up some color, after it hits them and bounces around.

For example, take a matte material like rubber – it still reflects 30% +/- of the light that hits it. You might be confusing reflectivity value with reflections, which occur in a mirror, but can also appear in a glossy or polished materials.

If you had an object that you purposely set to 0% reflectivity, it would look weird and un-natural. It might be OK for a super hero’s stealth vehicle from outer space, but that’s about it.