# Reducing polygon count

Hi

How does one reduce the polygon count?

I have been made aware of the decimate modifier. I’m modelling and writing a paper too so I sorta need to write multiple algorithms of how to do this.

Can someone please suggest a way and it’s pro’s and con’s

Thnx

I think the algorithm is going to be the easy part.
Distributing new maps is going to be the real kicker.

To what purpose will this algorithm be used btw?

If you use Blender 2.65 (latest build) the decimate modifier now keeps the UV mapping!

In the Blender 2.49 a “Reduce Poly” script was included - but it has been replaced by the Decimate Modifier in the new version.

http://wiki.blender.org/index.php/Doc:2.4/Manual/Modeling/Scripts

A Wiki entry to Simplygon explains some algorithms that can be used to automatically create LOD (Level of Detail) meshes.

The main principle is to find edges (and faces) that can be joined to reduce the number of polygons in a mesh.

One simple algorithm is to find edges that can be reduced (removed) with minimal effect on the topology of the original mesh - for this you need some sort of metric to compare the original and the reduced mesh - to find out “how much” the mesh has changed.

The more complicated algorithm is to create a NURBS surface from the original mesh and then use a resample algorithm to create a new mesh with less polygons by using a triangulation algorithm for NURBS surfaces. So basically you will “re-mesh” an object - best would actually to define the object using NURBS in the first place