Step 3. Multiplicitivefix

The fix for the multiplying shadow values is simple. We need to make the blinn put forth 100 %of its color value, and no shadow information, but still transfer its highlightinformation. Those familiar with compositing might notice that thisis a lot like unpremultiplying color values with a matte. (interestinglyin maya's shader network I've found that knowing a bit about post production,color correction and matte usage has been quite invaluable in making complexprocedural shaders.)

Create a Blend Colors node
Create a Surface Luminance node
Connect Surface Luminance to the Blender attribute of the Blend Colors node
Set Blend Color's Color1 to Black.
Set Blend Color's Color2 to White.
Connect Blend Color node to blinn1's Ambient attribute.



surface luminance connected to blender attribute. Blend Colors set to black and white.


Render to see the result. You can see that ourdarkness problem is fixed. In actuallity there is still some extradarkness (shown in this comparison newComp_hi.zip). This darkness is acceptable, though, since wet objects tend to get darkerbecause of how water reacts with the light.

Looks alright, but we aren't done yet. We need to add a bump map to the phongE material in order to simulate the small imperfections in the surface that the water would bring out.



the new fixed shader.

Step 4. Finishing Touches
To keep this easy we can just use the fractalthats already created.
Map the 2D Fractal to phongE's bump.
Set the Bump Height to 0.100
Set the Bump Filter to 0.100



our final shader

.Download the wetShader.mb file here. wetShader.zip

Obviously you would want to tweek this shader a little more. Perhaps add a higher frequencybump map to bring out more speckles. I hope that this tutorial willhelp you. It has certainly helped me. You can download this finished shader at right. Please email me with any questions or comments at mailto:seanfennell@inyc.com