### Quick guide for Mesh-cost

Take the following observations as a list of hints how you might possibly be able to lower the costs of your meshes.

1. Reducing the lowest visible LOD has high impact on resource costs. In fact it is the only way to get streaming costs down to reasonable numbers. I found that using a billboard-like approach for the lowest visible LOD gives very acceptable look, and reduces the Streaming costs.Please note that the lowest visible LOD varies with object size! For small objects up to a Bounding Box radius of ~5.43 meters (the distance between BBOX center and the BBOX corners) you can optimize the lowest LOD. If your meshes get bigger, then the lowest LOD is no longer used and the next higher LOD rules the price, and so forth until your mesh BBOX radius exceeds the size of ~43.4 meter where only the highest LOD is taken into account. Here is a table summarizing the numbers:
BBOX-Radius (smallest) BBOX-Radius (biggest) max cubic BBOX (example) Lowest visible LOD Comment
> 0 5.43 <6,6,6> LOWEST Costs can be reduce best with meshes <= this size
5.43 10.86 <12.5,12.5,12.5> LOW
10.86 43.4 <50,50,50> MEDIUM
43.4 > 43.4 HIGH Objects above this size only use highest LOD from any distance.

So slicing up a huge object into many smaller parts and import them as a link set would be an option for making buildings etc. with less PE (i refer to Drongle’s experiments on that)

2. Always add a physics mesh, because the default setting uses the medium mesh as physics shape and creates a fitting Convex hull, which will probably yield very high physics costs. Better use the lowest LOD for physics or generate your own physics mesh.
3. Optimize your object so that it looks good with medium LOD. Keep HIghes LOD for nice to haves but not really needed details. This seems to make the overall behaviour of the objects much smoother regarding look from a distance.
4. Give up Quad-centric modelling. It appears to me that Triangle centric modelling gives better ways for optimizing at least the streaming costs. Not that i say “only use triangles”. Quads are good for texturing, but triangles are good for reducing. So you will have to find out what goes best with your particular object. But do not avoid triangles !!!
5. Learn how to make optimal UV-maps. You can get rid of MANY faces if you make a proper UV-mapping. And you can enhance the look of your mesh significantly if you know how to unwrap.
6. Collecting many mesh objects into one linkset reduces the PE per mesh.
7. If you physics cost for a link set rules the PE, then set children in your linkset to physics type NONE wherever possible. That may reduce physics cost again.