So, I downloaded these nice conforming sunglasses for V4 from the free stuff and was using them for a render last night. The textures that come with them are ultra simple and I want a better effect on them. I remember a discussion on glass where BB showed some he'd created that looked like the type of mirrored colored glass on some tall high rise building, but I don't think he published those shaders. But the test renders he did look similar to what I had in mind for the sunglasses. He's very busy right now with the Lux exporter project, so I thought to ask if anyone had any ideas. Also, how do you make the material darker at the top and shade to lighter at the bottom?

Give me a link. I'll provide the shader. It will only take me 5 minutes.

Attached Link: http://www.renderosity.com/mod/freestuff/details.php?item_id=61337

Yes that is what I meant. I'm downloading it. I'll check it out.

I'm on a new computer and have to transfer some stuff from my old one before I can put the shader on it. Might be a little while.

Sure, no problem! Sigh, I really need a new computer myself, but I had  tooth infection suddenly flare up and I have to pay for a root canal, so the computer has to wait.

Do you want the glass to use refraction or transparency?

Refractive lenses cast a shadow. Transparency-based lenses do the right thing with shadows, but they can't color what you see through them. Strongly colored glasses are more realistic using a refractive shader. But you can fake colors with the trasnsparent ones, too, using diffuse. I have both kinds.

I'd prefer refraction, but either shader would work for the project. I'm not doing a super close up of V4's face. Would it help you if I posted a test render of the scene?

That looks great!

Wow! Both look fantastic, BB!

grin ooooh!

smirk I love to watch you work!

They're all the same shader - just different values for the parameters.

It would take me ten pages to explain all the things it can do. I'll put it in my book.

Thank you so much! I'll buy that book when it is ready! I'll be trying this out in just a few minutes!

Nice work both of you! 

go in a modeling software and seperate the glass from the glasses.
that way you can turn of the shadows.

 Haha there must some sort of mind link going on here.  I've been thinking about how to make a good reflective material for sun glasses (translation: I've been thinking of asking bagginsbill how to make a material for sun glasses) and here you are!   Fantastic!  Thanks.

Hello, first post on renderosity :)

"Also, how do you make the material darker at the top and shade to lighter at the bottom?"

If you mean like the "faded" preview on the daz forum: I used an opacity map. Its included in the sunglasses zip. Its called "El Sunglas FADED O1.png". I use the free daz studio, there you can load it in the surface tab under "opacity". I dont know if poser has an option like that though...
The letters at the end of the pictures in the zip file stand for:
C: color map
B: bump map
O: opacity map
R: reflection map

Great pictures! its nice to see people like the glasses!

Thanks,
Ele.

Hi elele - thanks for the glasses.

An opacity map could be used, but I built the gradient controls right into my glass shader so it isn't strictly needed.

The built-in gradient is adjustable as well. The nodes in the second column control the gradient. This kind of control would be harder to do with a map.

Gradient Min is the V coordinate where the gradient is black.

Gradient Max is the V coordinate where the gradient is white.

For these glasses, I set Min=.9 and Max = .7.

If you scroll down in the shader, you can see the actual gradient.

Then to apply the gradient, there are two other nodes of interest.

Transmission Gradient: Applies the gradient to the amount of light transmitted. It modulates the Transmission value. If this is set to 0, there is no gradient used on the transmission. If you set it to any value +0 to 1, then the gradient effect becomes progressively stronger on the transmission. In a couple of the shaders I set this to 1. This makes the top darker than the bottom.

You can also set this to a negative number form -0 to -1. In that case, the inverse of the gradient is used. This would make the bottom darker than the top.

The maximum transmission is still controlled by the Transmission node. So if you set it to .6, with a Transmission Gradient set to .5 then the effective transmission would be .3 to .6. If Transmission Gradient is set to 1, then the effective transmission would be 0 to .6.

Diffusity Gradient: Works the same but modulates the Diffusity value. Diffusity simulates some opaque material just under the surface of the glass - like tiny opaque particles suspended in the glass. It blocks some of the transmission and produces a diffuse reflection instead of refraction or transparency. If Diffusity is 1, then the material is completely opaque and transmits no light.

When Diffusity = 1, the material becomes more like an opaque glass. If you increase the Metallic value, it becomes more like a shiny metal.

When Metallic = 1, then the shader is 100% a shiny metal surface, with no ability to see any part of the interior.

If you change the IOR to 1.33, this material becomes water.

If you change the IOR to other numbers, it can variously become car paint, plastic, etc.

Those shaders seem great stuff! I'm still new to 3d and only just started with looking into the shader concept. From what I hear they are very dependant on the program used. Unfortunately I dont have the software yet to make them (or i havent figured it out). I'm thinking about upgrading (mostly because of the shader issue) to either studio advanced or carrara8.  But if i understand correctly i still wont be able to make poser shaders. But thanks to bagginsbill the poser crowd can rest easy.
 
Thanks bagginsbill! :)

Hmm, I tried following your above description to get the shader to be just plain glass for the sunglasses but I must have messed up somewhere, it rendered black. Do I need to change the Refract color to black?  And, knowing me, I'll try this as a water shader at some point......

If you change refract color to black, then there will be zero refraction. Don't do that.

For plain old clear glass, set IOR=1.54, Metallic=0, Transmission=.9 there thereabouts, Diffusity=0, Refraction Color=white, and Transmission Gradient=0.

Okay, got it to render as plain glass! Thank you so much!

 Awesome thread. Bookmarked!

All those nodes for that effect? Ok, I now know I will NEVER figure shaders out to that extent. I experiment around on some things and get some neat-o effects, but c'mon...

BB, you are THE "Man" for sure!

Actually, it's all those nodes so you have a bunch of parameters and combine a bunch of things that never get used all at once. Any one effect is nothing. If I built separate shaders, one for mirror, one for plain glass, one for smoky glass, one for orange glass, and then additional variations of each with a gradient on transmission, and then additional variations on each that had some diffuse in them, and then additional variations on each ...

Well then I'd have a couple thousand different materials, but each one would be less than 10 nodes.

The complexity of this shader comes only because I want one shader that can do a thousand effects. If you're willing to have a thousand shaders that each do one effect, then they can be simple indeed.

Most of it is simple math. People don't realize how trivial this is. Nodes are just not a good way of looking at anything that involves arithmetic.

For example, the ability to have the transmission gradient be modulated positive, negative, or not at all by the gradient requires 5 additional nodes. Any version that did not have the flexibility would be 0, 1, or 2 nodes for that aspect.

Here is how that part is done:
transMod = PM2(0, "Transmission Gradient")
antiGradient = 1 - gradient
transGradient = Blend(1, gradient, transMod)
transGradient = Blend(transGradient, antiGradient, -1 * transMod)
transmission *= transGradient

And the complexity is not real. It's just that looking at a program visually is astonishingly difficult.

This shader looks like spaghetti. Imagine, though, a diagram with not 100 nodes and all those wires, but rather one with 100,000 nodes. That is what you'd see if you visualized a typical program, such as notepad or winzip. If you were to visualize bigger programs, like Photoshop or Microsoft Word, you'd be looking at a million nodes.

Visual software is what the nodes are, and while that's cool for experimenting and learning, it's really not cool for serious development unless complexity management features are included. I'm actually a specialist in that area, dealing with complexity in a visual programming environment.

Beautiful glasses and shaders.

BVH file needed- hands on hips looking into distance, head down glasses off, look up and make threat to bad guy, head down glasses on, look back into distance. Should be able to get the golden Miami light myself

Quote - Beautiful glasses and shaders.

BVH file needed- hands on hips looking into distance, head down glasses off, look up and make threat to bad guy, head down glasses on, look back into distance. Should be able to get the golden Miami light myself

hehehehehehehe

For some reason for me these aren't rendering right- I think I'm having problems rendering glassy shaders at all for some reason. It just renders grey with no transparency or reflection, almost like a toon shader. I've got raytracing on, but I have a feeling it's a problem with my render settings. Any clue what's going on?

First, tell us which Poser version you are using?  A little extra information will help us narrow down the issues which may be occurring.

I'm setting everything up in poser 7, maybe I'll move to pp2012 for the final render. I've never had a problem with glass or reflections before though... do reflections work normally with hdri lighting?

Oh and also, I got the transparency working fine by deleting the alternate diffuse nodes. I guess I'm just working on reflections now, and maybe refraction.

One of the first things to check is probably that you've got something in your scene to be reflected, other than the default Poser grey background?

e.g. have you got an envsphere with an image map applied to it enclosing your scene?