duck

public class SceneryObjectSizeComparer : IComparer<SceneryObject>
{
    public int Compare (SceneryObject a, SceneryObject b)
    {
        float aSize = a.renderer.bounds.size.x * a.renderer.bounds.size.z;
        float bSize = b.renderer.bounds.size.x * b.renderer.bounds.size.z;
        if (aSize > bSize) {
            return 1;
        } else {
            return -1;
        }
    }
}