Refraction + Fog

V-Ray for SketchUp V-Ray for SketchUp :: General
1

I’m working on exterior scene . And i want to make green glass, when i add refraction layer and fog volume it looks good in the preview window but when i render it looks white and very reflective. I use 1.05
I even imported the vismat that came with the new release, no luck.
Btw on interior scene i didnt had that problem.

p.s- right now it’s a bit late so ill post screenshots tomorrow.

2

Re: Refraction + Fog

i had similar issue with my glass railing. pls try to explode ur group before render, and assign BOTH sides of glass mateiral on ur object, even u didn’t extrude it. my setting was only use refraction layer, check the affect shadow box, my Glossiness is 0.98; and IOR is 1.55
hopefully it works for you. cheers,

3

Re: Refraction + Fog

add some thickness to your gasses.

4

Re: Refraction + Fog

Thanks for your reply, the glass does have thickness.

Hey emily,
I’ve tried to explode and group/make component, also i checked that the material is applied to all the fasces.

Screen shots:
Vray Material (imported from the 1.05 library only bumped the fog multiplier to @1)

SU scene:

Render. Please notice that there is no green fog and no caustics.

5

Re: Refraction + Fog

First off, don’t worry about caustics…the fact that the shadow from the glass is not solid means there’s some sort of caustics there. Technically they’re being faked with Affect Shadows at the moment, but you actually want that…again don’t worry about it.

Secondly, your material settings just aren’t set up for a very thin object. You’re going off the material preview which for some material parameters doesn’t really have any bearing on what you’d actually expect in your rendering. Fog is one of those parameters, so don’t trust the preview. What’s going on is that your object is so thin that the fog itself doesn’t actually “accumulate” into any sort of darkened color. So just increase the multiplier and the fog effect will show up in your very thin object.

6

Re: Refraction + Fog

Thank you Damien for the explanation.
I’ve increased the Fog multiplier up to 100000000, and still no affect. :-[ ???

7

Re: Refraction + Fog

Then most likely the object itself is not an enclosed volume. Check and make sure its not just two surfaces that look like they’re joined. Thats the only reason why you wouldn’t get any fog.

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Re: Refraction + Fog

I’ve made a test . I made 40cm thick cube, applied the material to all it’s surfaces (both sides to each face).
Still have the fog problem unsolved.

SU scene, the cube selected

Render, Fog multiplier @100

The same, only refraction layer removed (notice the reflection difference, reflection layer is the same as in image above)