Rendering Leaves Using Hardware Tessellation

This paper presents early work on a new approach for level of detail (LOD) rendering of leaves. The approach takes advantage of the new tessellation engine in computer graphics hardware to produce quads for leafs or leaf cluster billboards as needed in a single pass. The approach is based on area preservation and as such is conceptually simple. It runs fully on the GPU, freeing the CPU for other operations and also limits the number of draw-calls as one only has to draw at most a few patches per tree. The nature of the approach also makes it a prime candidate for further optimization by instancing, reducing the number of draw-calls even further. Figure 1 Frame from a scene with leaves on more than 1100 trees, drawn using one patch per tree, producing up to 4225 leaf quads per input patch.