Is it possible to do a procedural shader for a window prop that appears to be different colors of glass pieced together like a stained glass window?  

Well, I'm not BagginsBill, but I'd say it's possible. Probably with the cellular shader... BB can no doubt come up with something that looks a lot better than this feeble attempt - but then I didn't spend much time on it either.

It works as a gel even, as you can see on Bong at the left - there's a light placed in front of them and it is nicely coloured by my "glass" -  a side effect I hadn't even thought of L

Another ( stupid primitive ! )

 Oooh that's much nicer. I couldn't get the black parts any smaller. Granted I didn't spend ALL that much time on it either. But this looks actually nice! steals screenshot for archive

 Hmm.. *pulling hair out here*

I can't replicate my "light gel effect" now- And of course I didn't save the original file so I can't check to see if I did anything with the lights (unwittingly, that is)

Any ideas? Also, no matter the refraction, I can't get my glass transparent without actually adding a transparency node - and the refraction should ideally make it transparent on it's own, just like real glass - right?

So.. Why won't this add colours to the light streaming through it? Is it because the lights is only computed at render time and it would throw itself into a loop if it should calculate the future? (a colour from a glass it hadn't yet calculated?)

And in that case, WTF happened on my Bong/Bonga pic yesterday where the lights WERE shown as dots on Bong?!

Quote -  So.. Why won't this add colours to the light streaming through it? Is it because the lights is only computed at render time and it would throw itself into a loop if it should calculate the future? (a colour from a glass it hadn't yet calculated?)

Cause poser dont render caustics ...

in re: poser 8, this one is gonna be a problem, excepting the case where the refractive surface is between the directional lite and the camera, with IDL unchecked.  but with IDL checked, the channels won't act as expected in SR0/SR1:

• alt_diffuse channel with various nodes applied to it will emit light
• translucence channel with colour/value will emit light, maybe even better than ambient channel
• no indirect lighting effects of transmission, reflection, refraction, caustics et al. (other than GIbounces off a diffuse posersurface)
• no indirect volumetric effects

so a stained glass window in P8/SR0/1 (IDL on) with translucence value/colour may look like it's transmitting colours selectively to a posersurface, but it's actually emitting colours.

 how about gather, would that cause a caustic effect?

 I just wonder how in the world I made the first pic then. And of course it was one of the few pz3 I didn't save :( Because SOMETHING is putting coloured spots on Bong, and if it isn't from the window, then where? O'm 99.9% sure I did NOT put anything on the light - but it's the only thing I can see then... But how? I used a pre-canned lightset, and it's usually just white (The P8 Backlight or whatever - not at the Poser pc now so I can't check...

I've never tried the gather node and as it is clear, the ambient is at 0 - also I didn't use IDL.... scratches head

I think it may be possible in poser to get transmitted light of various colours, along with refraction.  it just didn't work when I used glass pieces of finite thickness in poser - FFRender didn't transmit the colour of the glass onto another posersurface.  supposedly this is because that would be an example of caustics, as mentioned by athan above.  I'm assuming the above example in carrara (glass pieces with zero thickness) is the desired effect.  the transmitted colours appear on surfaces in carrara, whether or not caustics are enabled.  I can see it in trekkie's first example above, but it appears to be a blurred gel or mask on a light, as mentioned.

just wanna add that there's a stained glass cellular procedural in poser 8 (IIRC):

• diffuse value 2.9
• specular 1.0
• trans 0.83
• reflection 1.0
• et al.

haven't the foggiest how this corresponds to physical reality, but it looks nice facing the camera (no refractive nor transmissive fx AFAICT).

Hi folks. Sorry I didn't join in - been busy the last week.

I have attempted a Cellular-node stained glass in the past. I wasn't happy with the results and I put it away and ignored the problem, figuring I'd become more skillful in time and address the issue.

Well, I'm more skillful and I still can't fix the problem.  The Poser Cellular node is not implemented correctly. It generates gaps in the cellular pattern, and edges that are in the wrong place with the wrong gradient of information. I though perhaps I could work around it, but I can't.

Here was my first attempt from long ago, rendered on a floating one-sided square in my "under construction" environment.

And this was the best I could come up with this week. I still don't think it's good enough to use.

So I decided to cheat - to combine a simple image for color and edge info with nodes to create the look of unrefined glass we expect in such windows.

Here is the image I made in Photoshop. I'm no Photoshop wizard, BTW, so I'm sure others can do better patterns. I started with a white image. I Filter/Noise/Add Noise. Then I did Filter/Texture/Stained Glass. I messed with levels and saturation a bit. Then I added a black border. Finally I did a slight Gaussian blur to soften the edges of the black parts. I need that so I can get a tiny bit of gradient there to make the black parts 3D.

Then I built a shader to attach this image to, and render it. Here's the result.

Those of you who can draw nice patterns should find this useful.

Here's the shader. Attach any image you want for the pattern.

There's a sort-of famous architect/artist who makes stained glass windows like this for rich people. One of my friends has a window very similar to this in his home. I drew it as best as i can.

Here's the render.

That looks pretty good on the colored and clear parts.  However on the black parts it seems kinda flat.  Not sure if anything can be done about though without adding a b/d map and maybe giving a different specular map to the darker areas.

Just thinking with my fingers, don't mind me much.

Well I only made the black part 1/10th inch thick and we're looking straight at it, and I didn't put any specular on the black. Every image I ever saw of stained glass, the black was flat black.

How's this? I increased the displacement and added some specular.

.

New shader. I changed the IOR, too. Try different values for IOR - makes interesting effects.

.

Bill, I know what you mean about the black being flat but I think the one where you gave it a little more texture adds to it a little bit.

If it helps, for some reason I don't imagine, and it could just be me, the black part as perfectly smooth but either a little convex or concave.  I guess materials used could also play a part in it.  If we are talking about modern stained glass windows then a flat black plastic would be perfectly reasonable.  However if we were to talk about something before the advent of plastics or modern machining capabilities then I would expect something at least a little non-perfect.  Do you understand what I'm trying to get at?

Anyways the pictures look nice.

I understand the function of the clamp node, but I'm confused what and why your doing with it. Does that make any sense?

> Quote - I understand the function of the clamp node, but I'm confused what and why your doing with it. Does that make any sense?

Together with the preceding Subtract node, it creates a black and white mask from the colour image map, with slightly softened edges.

x < 0.25 becomes x = 0
x = 0.25 to 0.3 becomes x = 0 to 1
x > 0.3 becomes x = 1

The mask is used to apply diffuse colour, refraction, displacement and bump to just the glass areas.

*Edited to add: and in the latter shader, it is also inverted to apply specular to the leaded areas.

Poser does not do multi-colored shadows.  These are different from caustics, although they might seem similar.  Other rendering apps do not bundle them together though.

Gather node almost certainly cannot duplicate this, as it works globally, but you want your transparent multi-colored surface to cast a multi-colored shadow from the direct light, which Gather doesn't actually use (it's surface-based).  Gather is pretty similar to AO in that it is applied without regard to actual lights in the scene.  Basically Poser just can't do this, although someone is welcome to show otherwise.

BB - it may be of use to know that by and large - in the UK, at least - the black areas in stained glass are made from lead and are a kind of dull metallic grey, with occasional brighter areas and lumps where two pieces join. 

ST:

Since I was building it by hand, I took a few shortcuts. A major one was the assumption that you'd be using this in dim interior lighting, where the lead would be black anyway, as the transmitted light level is way higher than the interior light level. I ameliorated that somewhat using the specular - if you shine a light on the window, the lead will turn gray.

But to do this right, so that it responds to all lighting conditions, particularly where the interior light is higher than the exterior light, I would have to do a lot more Blending and masking. This is easy to do with matmatic, but I didn't use it here.

I took a few reference photos of a stained glass window - don't have them handy but they're somewhere in my pile of 22000 photos. When the interior is strongly lit, the glass has no color at all (the light coming from the glass is mostly reflection), and the lead looks almost white.

Right you are.  :)