Texture based fog color

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

I’m sure this has been brought up before and I’m not sure how it complicates things but I’d really like to add a texture map to the fog color.

V Miller

2

Hi,

this would only work with 3d Texturemaps. Additionally you would have to raymarch through the volume because the color could change along the ray. But it can be done. It would be much slower though.

This image was rendered with an atmospheric vray plugin, but I also did tests with vray volume shaders.

Best regards,

Dieter

3

I figured that it would slow down things quite a bit. And I would imagine it would lead to other problems when using 3d maps with deforming geometry.

But I would still like the option of putting a falloff map or something in there.

V Miller

4

But again you run into the issue where if you have a different colour of the front and the back of the object and since fog is a depth / 3d based effect ho would you blend between the two - might give some very odd results. How would you propose to use the falloff?

5

but I also did tests with vray volume shaders.

damn, where we can find them? :smile:

6

Well, it is not too difficult to think of some cheat for this; an interpolation between the start and end fog colors is probably not too hard to implement (although it may not be quite what you’d expect).

Best regards,
Vlado

7

Yeah that’s what I was thinking - since the effect builds up dependant on the thickness of the object a surface colour should get darker towards the thicker sections - if you had a dark colour facing camera and a light colour mapped to the back of it it might negate the depth darkening effect and give a weird look.