# Super Fly Coloured Glass

• I studied physics and math but not as a primary goal. They are basic requirements for any degree at MIT. It turns out those have absolutely nothing to contribute to my profession as a software engineer, but they're way useful for my CG hobby.

The application showing graphs in my previous post is "Grapes" - a free tool for visualizing math formulas. Each colored curve corresponds to the same colored function in the upper right. I used a parameter, p, in each one and varied them from 1 to 2, producing a family of curves for each formula.

So - the red lines, for example, are all from the y2 formula (1 - x ** p) ** (1 / p) with p varying from 1 to 2.

It shows us that when p is 1 the curve is a straight line, and when p is 2 the curve is a quarter of a circle. Other values interpolate between the line and the circle.

• @bagginsbill Absolutely fascinating. So how do you then use that graph to determine useful values to enter into Poser?

• The tricky glass trick does not work with indirect light (e.g. an environment sphere).
The best workaround i found is to use both isShadowRay and isDiffuseRay for the MixClosure, like this:

Hm. That's interesting. If I understand correctly why this is the case, it tells me that when a "shadow" ray is generated for direct lighting, it goes only to actual lights, and these "shadow" rays are not generated for our prop emitters. They're actually a cheat.

The addition of consulting the Diffuse ray seems like a good solution. I can't think of any reason not to do that in the general case.

True. I've read some texts about how cycles works. The shadow rays are always fired to an actual light, to help the renderer find the lights in the scene. In Blender, you have "Light windows", which aren't lights but just frames to guide the shadow rays to bright areas, so that you can help the renderer.

Poser does not have the helper frames IMHO, so the shadow ray will always seek a light.

• @bagginsbill said in Super Fly Coloured Glass:
Your max bounces is 3. It takes 4 bounces to get all the way through both walls of a cylinder or glass. It takes more than that to get through other more complicated shapes and angles, like a glass Andy figure.

BB, you are a hero!!

I've been looking around for materials and settings for some glass jars, I've made, and all of them came out with a dark inner back-side of the glass. I tried to reverse the normals for the inside of the glass, but to no avail.

I can make it work with a simple Firefly-shader, but that does not provide the quality I'm after.

Thanks mate!!

• I can make it work with a simple Firefly-shader, but that does not provide the quality I'm after.

Ooooh... Care to share that Firefly shader?

• It's the season for resurrection. So I'm trying this old thread.

Loving the Tricky glass, but if I want frosted glass ... then which parameters do I change? Which one defines the transparency/opacity of the glass? (actually I want milky glass for a lamp shade ... but a milk shader has also eluded me so far. I've gotten close, in Firefly, but Superfly is a different beast that I have far from tamed :D )

• Hi,

You need to add something to the volume output, same as you do for coloured glass. frosted you would just add a bump map to the normal shader.

This is what I used for frosted glass

it came out like this (2 panes for added privacy)

Here it is as part of the divider in Deanna's cabin

• Example ... I can make the lamp light up with the Emission thingie. but then ALL of the glass is lighted equally and it just doesn't look right ...

SO if the glass was "right" I could put a flame of some sort inside ... At least I think so ?

• @trekkiegrrrl Yes, don't make the glass emissive, the flame, or whatever is inside should be emissive and the glass will be see through. If no one else chips in before tomorrow I will have a look as I have a similar lamp. Though last time I used it was when I was experimenting with Lux and that was really nice, but then SF came along and I sort of lost touch with Lux

• @trekkiegrrrl if the glass has the thickness, use tricky glass with roughness o.8-1.
If the glass is just a sheet of polygons, you should mix glossy, translucent and transparent shaders. Do NOT use glass or refractive shader in the latter case, or your lamp will look like a solid glass ball.