Detail View

We present a novel terrain rendering algorithm based on GPU tessellation. The planar domain of a terrain area is partitioned into a set of tiles, and a coarse-grained quadtree is constructed for each tile. Then, each node of the quadtree is input to the GPU pipeline together with its own tessellation factors. The nodes are tessellated and the vertices of the tessellated mesh are displaced by filtering the displacement maps. In order to optimize the use of GPU tessellation, a multi-resolution scheme is designed. Moreover, this scheme is easily able to cope with procedural noise to synthesize unlimited resolution detail. The efficiency of the proposed approach is proven through experiments on real data of the earth and lunar surfaces.

Contents 1
List of Figures 3
1 Introduction 1
2 Related work 4
2.1 Terrain rendering technique 4
2.2 GPU based terrain rendering 6
2.3 Procedural Noise and Noise-by-Example 7
2.4 Terrain Amplification with Procedural Method 9
3 GPU pipeline for terrain rendering 12
4 Multi-resolution scheme 14
4.1 Tile and patch 14
4.2 Object-space errors 16
4.3 Quadtree and inner LODs 17
4.4 Edge LODs 18
4.5 Quadtree update 19
5 Geometry images for terrain rendering 23
5.1 Feature-sensitive Parameterization 25
5.2 Terrain Rendering with FGIs 27
5.3 Zippering 28
6 Detail synthesis for unlimited terrain resolution 30
6.1 Procedural Detail 32
6.2 Noise by Example 33
6.3 Stamped Detail 36
6.4 Blending Procedural and Stamped Details 37
7 Terrain surrface rendering with detail 40
7.1 Quadtree subdivision and GPU processing 40
7.2 Tessellation and Quadtree Update 42
7.3 Noise Interpolation 44
7.4 Unlimited Resolution and Unlimited Detail 46
7.5 Image Textures and Normals 47
8 Experimental Results and Discussions 48
8.1 Multi-resolution terrain rendering 48
8.1.1 Out-of-Core rendering and view frustum culling 49
8.1.2 Height Mapping vs. FGI Mapping 50
8.1.3 Performance Comparison 51
8.1.4 Screen-space Error Threshold 52
8.1.5 Texture Resolution 54
8.2 Unlimited-resolution terrain rendering 56
8.2.1 Implementation and Performances 56
8.2.2 Procedural and Stamped Details 60
9 Conclusion 67
Bibliography 71