Hello bagginsbill. I bought a product that was a set of shaders to do both an empty glass and solid glass etc. but it just renders black even though I have raytracing etc. The materials room transparency and refraction wacro that come with Poser are what I have been using instead and they do work but I am hoping you could give some advise on making these materials better. Mainly I am wanting good shaders for window glass in scenes and also for eye glasses glass. Can you explain how the refraction works and how it should be used for these effects please? Also say for a pool of water in which someone is standing? I am somewhat confused by how the refraction shader interacts with transparency and reflection and diffuse in a material and your help would be very much appreciated by me and others too I am sure. I also want to get reflections on shiny floors that are not so mirror-like but that fade or scatter as the reflection is more distant from the source. I understand of course if you don't have time and maybe someone else can help if you are too busy which is why I am not IMing you..

Good questions. I've answered these before, but I have better answers than the past, and also some more subtleties and complications to deal with, such as GC.

This will take a longish while, and being 1 in the morning I have to get to sleep. But I'll come back.

Oh - forgot the short answer.

Use the Fresnel node.

Set Diffuse_Value = 0. Specular_Value = 0.

Plug a Fresnel node into Alternate_Diffuse. The Alternate_Diffuse color should be white.

Set the index of refraction (IOR) on the Fresnel node to 1.54. You have glass.

Set it to 1.33. You have water.

Clear glass and clear water only, and unless you are using Poser Pro, this has no gamma correction. And it mistakenly casts shadows. But it's a start.

Whilst he's sleeping, allow me to point you to this:
www.runtimedna.com/forum/showthread.php

I'm re-reading for the fifth time... lots of stuff I didn't get the first time. It's really complete!

This weekend I'll try to post a glass tutorial. But it's a big subject, and also is complicated by which rendering color space management technique you want to deal with.

Poser 7 or less has no gamma correction or tone mapping, so I use GC shaders for that.

Poser Pro has built-in gamma correction, so I don't need GC shaders and things are a lot simpler.

Poser 8 has tone mapping, which isn't exactly as good as GC so we can use GC shaders as with Poser 7. Or we can try to deal with tone mapping and adjust some things in the shaders to get us close to a GC effect. But, if you're going to use IDL, then GC shaders are a bit of a problem, and we'd hack in a different way. And if you're going to use IDL and tone mapping, we hack still another way.

I don't want to write about all that at the moment. So pick one.

Also, thin glass versus thick glass are different and require different techniques.

Also, if the glass is not its own prop where you can turn off "cast shadows" we have to deal with it casting a shadow. Or maybe not - depends on the situation. Pick that too.

Quote - This weekend I'll try to post a glass tutorial. But it's a big subject, and also is complicated by which rendering color space management technique you want to deal with.

Poser 7 or less has no gamma correction or tone mapping, so I use GC shaders for that.

Poser Pro has built-in gamma correction, so I don't need GC shaders and things are a lot simpler.

Poser 8 has tone mapping, which isn't exactly as good as GC so we can use GC shaders as with Poser 7. Or we can try to deal with tone mapping and adjust some things in the shaders to get us close to a GC effect. But, if you're going to use IDL, then GC shaders are a bit of a problem, and we'd hack in a different way. And if you're going to use IDL and tone mapping, we hack still another way.

I don't want to write about all that at the moment. So pick one.

Also, thin glass versus thick glass are different and require different techniques.

Also, if the glass is not its own prop where you can turn off "cast shadows" we have to deal with it casting a shadow. Or maybe not - depends on the situation. Pick that too.

May I pick? Please? How about: thin glass (like a window pane) with GC (or tone mapping - I'd be keen to see the difference!) in Poser 7. Oh, and a discussion on IOR for glass (or a nod, whichever) would be nice. Still trying to pound that into this thick skull...

Poser 8 is my preference and maybe quarter inch or eighth inch glass and a solid glass too if possible. Thanks.

Well, I was going to ask for thin glass in Poser 8 with Gamma Correction and IDL.

I have a feeling, BB, you will be covering all bases at this rate.

Window glass is thin, the surfaces are flat and parallel. Since the thickness doesn't change and it's not thick, you can get away with not using refraction, but just transparency instead. This solves the shadow casting problem.

I have pretty decent solutions for this ready to go, because I use them in my new arch-vis project.

Here's an example.

Hello,
I played a bit with the glass shader from that thread, the 4-node version:

The surface looks really good, but the thickness of the glass seems to have no
influence on the refraction.
I made a test with a cube, scaled to 5% thickness, and the same, at 20%.
I would expect 4 times more shift of the refracted picture, but it is essentially
the same. Also, it does not matter if I use just the fresnel node.

My suspicion is, that Poser only refracts when a ray enters a surface, but not
when it leaves the refracting material. Can anyone confirm this?
If so, is there a trick to work around that?

Best regards,
   Micael

best regards,

Bopper.

Best regards,
   Michael