In this project, I wanted to create a clear, silver metallic paint. It didn't need to be photorealistic, but it did need to be very shiny. I didn't use the common shellac material or blend material, but the new V-Ray car paint shader, which is very easy and good.
There were three main layers in this shader: bottom, flakes and top part.
The basic reflection controlled the power of the bottom paint's reflection, 0.5 suited for most of the scene. Basic glossiness controlled the spread of the bottom paint's glossy reflection; 0.72 is a comfort value. In fact, the basic layer was a simple vraymtl with a ward shader, which simplified the parameters for the car paint effects.
The flake layer can be used to create the flakes effect. I didn't use this function in this project, so just set the common values to 0.00 and the flake map size to 64, to save system memory.
There was only one parameter in the coat layer that I needed to adjust: the coat strength. The default value of 0.05 means a common car, 0.08 means a good car. Here, 0.12 was a very shiny car.
At last, I was able to remove most of the noise by setting the subdivs to 32 (Fig.35).
After setting the material's parameters, I could give a color to the paint. I added a falloff map in the base color slot, set the far side to black and the near side to a bright gray (75 x 75 x 75 - this is "bright" because I used the Gamma correction). Then I adjusted the curve, as shown in Fig.36, and got a nice, silver car paint.
This is typical car paint. Because of the LWF, I was able to use this shader everywhere; it just needed a little adjusting.
The main difference between a car's glass shader and some archviz shaders is that you need to make sure that the glass object is solid. By doing this you will get a correct refraction result. In Fig.37 you will see the terrible result I got because the object has only one surface.