Frosted images on glass
Posted Mart 15, 2008on:
All images are the same in 3D. They have different intensity values in different locations across the image. It’s all about intensity. Once you understand this concept in any 3d software program, you can master materials. Essentially 3ds max reads black as being 0% and white being 100%. Everything grey is in between depending on how grey they are. This works for any slot in your material that allows a map to be read for it’s value. By default they have numerical values, but that will apply to the entire material. If there is a pattern that you want the values to follow…well that’s when you use an image map.
If this image were plugged into the opacity slot, then it would be an opacity map. All of the black areas would be 0% opaque, and all of the white areas would be 100% opaque. If it were plugged into the reflection slot then it would be a reflection map, and all of the black areas would be 0% reflective and all of the white areas would be….you get the idea.
In this example for frosted glass, I had to ask “what is it that makes the glass look frosted?” The major difference between frosted glass and regular glass is that you can’t see through frosted glass like you can regular. Why can’t you see through the frosted glass if it’s made out of the same material? That’s because light scatters differently. In the A&D material, refraction is what controls the transparency, and glossiness is what controls how refraction is scattered. So that’s where I plugged my map into.
Sometimes you can plug the map in straight. But in this case to get the most control of your colors, I used a Mix map, then plugged my image into the mix amount. This way I can make sure that the only intensity values used for glossiness will be white and black.
If you created your image map, and screwed up by reversing the black and whites, this is also a good way to switch the blacks with the whites.
So now my whites have a glossiness of 1.0 (pure refraction), and black has a glossiness of 0.0 (no refraction), and it gives me that frosted glass look!