Hierarchical triangular patches for terrain rendering with their matching blocks

To efficiently represent large artificial terrains on today's graphic hardwares, we propose a new terrain rendering scheme with hierarchical triangular patches and pre-constructed match ing blocks. It renders terrain patches at different LODs(levels-of-details) according to the current visual requirement. The hierarchical structure can reduce the total number of 'draw primitive(DirectX)' calls significantly by replacing a large set of triangles with a single patch where appropriate while other conventional methods try to reduce the total number of primitives to be rendered. After the initial construction of patches, the new scheme does not re-triangulate during runtime, further enhancing its performance. We also propose a specially designed matching method to eliminate cracks on the boundaries between neighboring patches. It constructs a few matching blocks at initialization with which it replaces original patches on boundaries where cracks may occur.