I started the very initial groundwork for LOD support. The idea being that for a specific tree, one might configure different LOD parameters for different distances. The goal is to have three basic reduction strategies.
Strategy 1: simply reduce the levels of the tree that are drawn. The theory being that from a distance, the interior branches or the low level roots won’t really be seen anyway. Furthermore, at distance it is often acceptable to use a reduced number of radials in the branch segments.
Strategy 2: tricksy hobbitses… a flattened polygon render where branch segments are rendered with lit billboarded quads. Hard to describe quickly… if this works this will be the magic LOD as I should be able to reduce the right kind of tree down to about 320 triangles or so. Even less if I can cut the leaf canopy in half… could be as few as 180. We’ll see.
Strategy 3: generate an impostor atlas of a few sample trees to render on lit billboarded quads. This will obviously end up being two triangles per tree.
So far, I’ve been playing with strategy 1 and the results are pretty encouraging. I was really hoping for a 4:1 reduction but with the starter tree it’s an even better 7:1 and the quality is nice: Rendering 7 trees for the price of one is savings you can count on.
Note: top is fully quality, bottom is reduced quality.