Variable Frit Glass material

[Artifex-Auctor]

Ok, so this happens a lot: a boss asks me to do a rendering where the glass on a tall building >250' starts at the base with a tight white glass frit and fades the frit at the top so that it's much lighter. How the heck to do that I wonder? I've tried using a fresnel with a map in each color thinking that the angle would cause the blend, but this working in all directions and I only want to work in vertical.

Anyone having any thoughts or has anyone ever had to make a material like this? I want to avoid the situation where I have to draw a VERY tall bitmap to use in an opacity channel.

[dalomar_cg]

Re: Variable Frit Glass material

What exactly is Frit?

[Gijs]

Re: Variable Frit Glass material

googled this:

[url]http://www.commercialwindows.umn.edu/materials_glazing5.php[//url]

if it is a kind of silkscreen, then this should be quite easy to accomplish with a transparency map in the diffuse layer.

[dalomar_cg]

Re: Variable Frit Glass material

So is it always in that pattern??? or is it a gradient that you're looking for. IMHO the easiest/most attractive way might be through mapping glossiness, although it might take a little longer.

[Artifex-Auctor]

Re: Variable Frit Glass material

I'm looking for a horizontal frit pattern that starts light and wide spaced near the ground and gets progressively tighter and more opaque toward the vertical. So in a sense it is not just a gradient, but a gradient made up of bars of white opaque silkscreen that tighten toward the top.

I've seen a few comments about an angle blend material . . . but can't find such a thing in the material editor. Where is this option for the angle-blend? I can only find a plain texture blend as a map, not a specific angle-blend material.

A map could be placed in any number of different channels to control the opacity. The problem is that I want a smooth blend across about 90 feeet of vertical space comprised of about 20 separate glass panels vertically, so I was hoping for something that could be used to start with one pattern near the ground and blend to another pattern at the sky.

[Gijs]

Re: Variable Frit Glass material

David Rutten's explicit history could do that, no doubt. But if you need it faster, why not make a simple map in illustrator? or model it and place it inside the glass panels as planar surface objects.

[Artifex-Auctor]

Re: Variable Frit Glass material

I solved the problem using a really tall and narrow map in the opacity channel. But I want to find a more sophisticated way of doing it that doesn't require serious anti-aliasing to make render clear.

What is David Ruttan's "explicit history"? As you can tell . . . I'm new at this.

[Gijs]

Re: Variable Frit Glass material

type explicit history in youtube to get an idea of what it does. it is really cool stuff.

I think I still don't have an exact clue of what you want to accomplish. maybe post a picture would help.

[dalomar_cg]

Re: Variable Frit Glass material

Explicit History Explanation:

With the advent of Rhino 4, the ability to link commands with the geometry that created them was added. This is useful, but fairly uncontrolled behavior. If you set it up when you make the geometry, then great, but if you missed the chance, then you've got to deal with it or remake it. Also, if the connection between the geometry that was referenced and what was created is broken, then there's no way to re-reference the geometry...again an opportunity lost.

So this sets the stage for what would become explicit history. EH basically allows you to control these operations. To create the connection between pieces of data and the process that creates them. EH goes way beyond simply referencing geometry A to command B as seen in Rhino's history and allows you to dynamically create those references with multiple pieces of data. It also allows for logical operations (math and such) which can have the data become much more variable then just its own properties. Lastly, you can also extract different pieces of information which can then be reconnected back to different pieces of the model.

The end result is much more parametric behavior then just a simple connection of curves to a loft. Extremely complex relations can be made and it allow Rhino to become much more interactive then before.

I would highly suggest that you take a look at EH. Its fun, its not very hard to use, its UI is very intuitive, and you can do some pretty intersting things with it.

YouTube it...David's stuff is up there as well as a few pieces of my own. Also do a search on the Rhino Newsgroup as I've posted a few tutorials for it over there.

Enjoy ;D...(on a side note, I don't know how EH would solve you're problem though ;D)