created this tutorial because manypeople in computergraphics fret greatly trying to make a wet looking shader. I also doit with a fast rendering shader that is easy and fast to set up,and doesn'tuse any plugins. It also doesn't hinder rendering speedlikea layeredshader can. Let's start.

I personally prefer to use the Hypeshadewindow so all of these images will refer to that. If you use the multi-lister the workflow will be slightly different but the connections are all the same.

Step 1. The base Shader

We'll start by creating a sphere and a regular Blinn shader.
Also create two distant lights and positionthem as you like to lightthe scene for render previewing.





basic scene setup.
Create a Blinn Shader and assignit to the sphere.
Set the Eccentricity to 0.500
Set the Specular Roll Off to 0.320

These settings will give us a nice broad specular highlighton the base shader. Now we create a 2D Fractal texture to add colortothe base shader.



blinn shader next to rendered scene.


the image now and you will notice one problem. As the phongEgets the Blinn's specular and color output directly, it also gets the blinn'sshaded area as well as its own shading. What is happening technicallyis the darkness values for both the blin and the phongE are being multipliedinternally, thus resulting in nearly the same light value, but excessivlydark shadow values. You will notice this pointed out in the pictureat right See how the new connected phong's shadow area is much darkerthan the original blinn's used to be. We will fix this on the nextpage.



phongE's color mapped with blinn's outColor attribute.



notice the overly dark areas of the phongE mapped with the blinn outColor

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

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

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