Coloring glass shader

[Oshyan]

Sounds good, please do!

- Oshyan

[j meyer]

Spent several hours last night testing with procedural and imported objects
in TG 3.2.03 and TG 3.1.02 and even TG 2.5 and could refresh my memory and
got the answers to some questions that were not discussed here.
I won't go into everything to not confuse you too much hopefully.

The issues I perceived the other day can be illustrated with images from the
latest version (TG 3.2.03) alone I think.

[attach=1]

You'll notice that difference in the volume density values.That's because the
water shader has a range from 0 to 10 by default while the glass shader's
range goes from 0 to 1000.
With double sided checked (which gives the same glass effect like the water
shader method) you can crank the value all the way up and won't see any
color.As you can see in row #2 the procedurals show some weird light blue
plane effect.
In row #3 the procedurals just show some grainy noise.

For the sake of completeness a comparison between TG 3.1 and 3.2.

[attach=2]

Hope that's good enough an illustration of the issues.

[j meyer]

One more thing I want to show although it has nothing to do with
coloring the glass shader.
This image depicts the reason for using the water shader in conjunction
with a reflective shader instead of using the water shader's reflection
feature.

[attach=1]

Hope you don't mind,but since it's related to glass effects in TG I
thought it's better here than making a new thread.

[archonforest]

great stuff dude. I learned something

[archonforest]

If I apply the default glass shader to a built in sphere it looks very glassy. If I apply the same default glass shader into an imported object I got some very dark looking non kinda glassy object. Why is that? Maybe my imported obj is wrong or something?

[j meyer]

Hard to say without knowing your object or the way you connected things.

[archonforest]

Hard to say without knowing your object or the way you connected things.

Yeah sure...
Well the object was made via PS. I had a tiff file with some white shape on it. I extruded in PS and saved as .obj. Then exported into TG. Connected the glass shader directly to the surface shader of the object. Is this enough info as I cannot give out the object itself...

[j meyer]

Well I don't know anything about PS generated meshes.
In case surface shader of the model means the default shader that's
connected to the grey part node try it without the default shader.
Beyond that I have no idea at the moment,sorry.

[archonforest]

Okay got it.
I uploaded a test file if anybody can look at it and perhaps tell me why the object is not see through glassy?
I have a feeling that the object itself is wrongly made... Anycow any input is appreciated

[archonforest]

Well never mind... I used an in build object that is in PS3d and that worked okay in TG with the default glass shader
So looks like the object I made (not build in in PS) was saved with a shader and that created the problem for TG

[Dune]

Interesting tests, Jochen. Thanks for that. It seems like an imported sphere is nicer, less grainy, and I suspect that's because it's rendered in a RT manner, while the TG sphere is rendered differently. Something that would still need some improvement is the darkness of the shadows through a near transparent object. And seeing foam on other sides of waves 

[j meyer]

Attila - After thinking about your problem again I came to the conclusion
          that it might be caused by flipped normals.While these are supposed
          to render correct on a shaded object thea may cause problems with
          reflections and so on.
          Quote from the change log:
          On surfaces that have inverted normals, diffuse lighting now renders as though the normals were not inverted. Flipped normals may still have consequences for other types of shading, such as reflection and refraction.

           So maybe it's that.

[archonforest]

Attila - After thinking about your problem again I came to the conclusion
          that it might be caused by flipped normals.While these are supposed
          to render correct on a shaded object thea may cause problems with
          reflections and so on.
          Quote from the change log:
          On surfaces that have inverted normals, diffuse lighting now renders as though the normals were not inverted. Flipped normals may still have consequences for other types of shading, such as reflection and refraction.

           So maybe it's that.

Thx a lot for the info. I will chk it out. Mean time I managed to work around and played with the glass sliders and got pleasing results. The only thing still puzzles me that why TG is not rendering the scene that is behind the glass...

[Kadri]

Nice thread with good info guys.

[Dune]

The only thing still puzzles me that why TG is not rendering the scene that is behind the glass...

It does doesn't it? I see stuff through the glass. But if you mean; why doesn't it render in high detail, then the answer is in the render subdivision settings (which are inside the render shader, and default at 0.25). Make it 1 and it's perfect, though takes longer to render.