1. 3D Game Engine Design Chapter 11 TERRAIN

2. What are covered ? Dynamic Level of Detail Tessellation – Terrain Topology – Simplification – Full Algorithm Height Fields from Point Sets of Triangle Meshes – Linear Interpolation – Quadratic Interpolation

3. Terrain Topology quad tree

4. Terrain Topology 3x3 primitive block quad tree

5. Terrain Topology 3x3 primitive block

6. Block Topology

7. Simplification

8. Vertex-Based Simplification – more accurate, but expensive Block-Based Simplification – cheap, pre-process for VB simplification Vertex-dependency – post-process for BB simplification Some assumptions available – distant terrain & close terrain

9. Vertex-Based Simplification LwLw

10. From Equation 3.16 : Camera view direction vector : Screen space distance threshold

11. Block-Based Simplification ; lowest resolution ; highest resolution ; interval of uncertainty

12. Vertex Dependency

14. Some Assumptions Available Distant Terrain Assumption Close Terrain Assumption

15. Full Algorithm InitBV();// Initialize Blocks & Vertices InitQ();// Initialize Queue for( each frame ) do { if ( cam.eye has changed ) then { ResetBlocks(); SimplifyBlocks( cam ); SimplifyVertices( cam ); } RenderBlocks(); }

16. Height Fields From PS or TM Linear Interpolation – Barycentric combination Quadratic Interpolation – Subdivision – Bezier Triangle

17. HF from PS or TM ; Linear Barycentric combination

18. HF from PS or TM ; Quadratic Cendes and Wong 1987 Input : ( x i, y i, f(x i, y i ), f x (x i, y i ), f y (x i, y i ) ) Procedure – Subdivision – Bezier net construction Output : C 1 continuous quadratic interpolation

19. HF from PS or TM ; Quadratic Step 0 ; Triangle mesh ( in 2D )

20. HF from PS or TM ; Quadratic Step 1 ; Inscribed circle point

21. HF from PS or TM ; Quadratic Step 2 ; Subdivision

22. HF from PS or TM ; Quadratic Bezier Triangle Revisited

23. HF from PS or TM ; Quadratic Bezier Triangle Revisited

24. HF from PS or TM ; Quadratic Step 3 ; Bezier net construction

25. HF from PS or TM ; Quadratic Step 4 ; Interpolate + C1 continuity