@Override
        public String toString() {
            String out = "Triangle{\n";
            for (int i = 0; i < 3; i++) {
                out += vertexId[i] + " : " + vertex[i].toString() + "\n";
            }
            out += '}';
            return out;
        }
Collapses vertices until the cost exceeds the given value.

Collapse cost indicates how much inaccuracy the
reduction causes. This generates the best LOD output, but the collapse
cost is implementation-dependant.
jme3-core/src/tools/java/jme3tools/optimize/LodGenerator.java