Date : Sometime 2008
Maya Version : Should work with all versions of Maya

This script was created because while I was creating a LOD models , I found that eliminating polygons which was responsible for smooth – hard edged look on the model left my low polygon’s edges looking too hard.

The idea is to bend the vertex normals around the hard edges closer or further apart to simulate the “softer or harder hard edged look” than what Maya gives you by default.

The name of the window is “Average Normal Control”. It is because when I first start making it , I wanted to control the amount of the averaged normal of the vertices. But the result is the same.

The result is bit hard to describe but it is perhaps better explained by looking at these pictures.

For an example sake , lets say we have our “high” poly model like this one :

high polygon model

without wireframe

The high polygon model tries to keep a decent hard edge looking but not too hard by adding a bevel to one of the edges as shown above. In this situation when you create a lower LOD model, you would natually want to get rid of the bevel. But doing so will create either too soft or hard edges as shown below :

low poly model

too soft looking

too sharp looking

After selecting the middle edge of the low polygon model and then applying 50% “TOWARDS!” button you can see that it bent the normal of the vertices of the edges so that it looks half way between hard and soft look.

original high polygon model

bent normal low polygon model

Benefit of this method is that when the model changes from high polygon to lower polygon, the difference on look of hard edges are kept as minimal as possible. Down side is that it is just an extra work really. It does not work in all the cases , but I found that in the extreme cases, it worked well and helped to minimise visual pop ups during the LOD transition.

How to run this scipt :

• Copy the script to your usual script folder. This could be your default Maya script folder under My documents
• Source the file if necessary by typing : source Cas_normal_control and then pressing crtl+enter in the script editor
• Run script : NC_normal_control and then pressing crtl+enter in the script editor
• Combine both source and command into one short cut button on your shelf for easy access next time

Cas_normalControl