Pro Optimize issue

[Anonymous]

I'm getting completely different results with what appear to be the same settings. I'm trying to get the results like the mesh on the right where the optimization is spread across the mesh. The only options I have checked are Prevent Flipped Normans and Exclude Borders. What's causing the result on the left? Thanks. 

[Anonymous]

Assuming the geometry of both before optimizing is similar but not identical.

The tendency of the pro optimizer, as it is the case aslo of the optimizer from Zbrush, is to crunch heavily anything that is flat. This gives at certain levels of optimization a huge difference between areas that are flat and not. The idea is that a flat area doesn't need lots polys to be rendered but this can create problems in some situations.

There are other commercial  optimizers that avoid this problem, for example "Polygon cruncher" from Mootools.

[Anonymous]

The mesh on the right was created with Pro Optomizer also, was that a fluke? I abandoned optimizing in Max in favor of Maya a long time ago. For whatever reason I gave it a try and I was surprised I got decent results. But I can't reproduce those results. Thanks.

[Anonymous · Accepted solution]

The way Max optimizes can be OK for some things, but not for others.

If Max finds a perfectly flat surface will create as few polys as possible resulting in a few very stretched triangles. This looks very different if the surface is irregular, even only very slightly (like a very smooth noise), where it will create a more regular geometry. As commented the optimizer of Zbrush does the same. My guess is that the model of the left had a wider perfectly flat surface. 

If you want to edit further the geometry those large triangles become a problem as you can not deform them etc. Max and Zbrush optimization works OK if you don't want to edit or deform further the geometry and you don't mind those triangles.

Polygon Cruncher in contrast will always leave a certain mesh intensity regardless how flat is the geometry, making a more regular mesh. For some things this could be considered a waste of polys if your objective is only reduce polys.

[Anonymous]

That was it, I had applied a noise modifier to the mesh on the right. Thank you.