Thin Glass Render

[avajjon]

Hello,

There is a little feature missing in the specular shader that keeps bugging me for some time. (or maybe I don't know how to do it)

Example: I try to render a car model which I have bought. I use a simple specular shader for the windshield, nothing fancy.

Since the model has simple polygon plane wihtout thickness, refracted rays don't get back to the angle they hit the glass, because they think they are still in the glass. Which is computationally true.

Now I set the index to 0 to compensate the refraction, but this time I have lost all the reflection as well.

I have extruded the glass. 0.01 units. Now everything looks fine.

Is there a better way to achieve this without adding geometry into the scene ? There are thousands of 3d models have been modeled without glass thickness, cars, planes, trains, especially architectural models.

I think this can be added to the shader, I think Mental Ray has a feature like this in the shader (thin glass check box)