250 likes | 374 Vues
This overview presents innovative methods for generating computer-generated geometry, focusing on parametric synthesis and synthesis by analogy. Techniques for creating landscapes and mazes are discussed, including the use of height maps and recursive backtracking algorithms. Challenges in generating meaningful, high-detail geometry, reminiscent of human architecture, are outlined. Proposed projects aim to enhance geometry generation through the application of design templates, adding textures and details automatically. The synthesis process is illustrated with applications in gaming, architectural design, and more.
E N D
Geometry Synthesis Mathias Ricken Rice Undergraduate Scholar Program November 11, 2003
Overview • Computer-Generated Geometry • Uses • Creation • Previous Work • Landscapes • Mazes • Problems • Geometry Synthesis • Parametric synthesis • Synthesis by analogy
Creating Geometry • Hand-Crafted • Computer games 1 Man-Year for 40 hours of game play 2 • Automation • Lower costs • Better training • Higher replay value
Landscapes • Height Map • Matrix of numbers • e.g. one per square foot • Numbers Elevation • Filters • Smoothen or roughen landscape • Add rivers and lakes
Mazes • Recursive Backtracking • Regular grid • 2-Dimensional • Creates perfect mazes • All cells connected in exactly one way • No loops algorithm explained in extra slides
Problems • Landscapes • Large scale, but low detail • Only natural, not artificial • Mazes • 2-dimensional • Small scale • Not reminiscent of human architecture
Proposed Project • Create meaningful geometry • Similar to human architecture • 3-dimensional • High detail • Algorithms • Parametric synthesis • Synthesis by analogy
Parametric Synthesis • Create a network of rooms and corridors • Generalization of DungeonMaker algorithm 4 • Tunnelers, agents (“robots”) • Randomly • Probabilities controlled by parameters • change direction • create rooms • create branches
Parametric Synthesis • Generalize • 3D, not 2D • Not grid-based 4 • Examples of Parameters • Frequencies • Dimensions • Angles • Alignment
Synthesis by Analogy • Automatically enhance bare geometry created by parametric synthesis • Use design templates • Add colors, patterns, details 5
Texture Synthesis by Analogy • Given small texture, create arbitrarily large similar texture • Few visual flaws • Similar to a jigsaw puzzle • Look at the surrounding pieces (neighborhood) and pick best match • Does not have to be perfect fit • Pieces can be used more than once or not at all
Texture Synthesis by Analogy Template Synthesis Target • Randomly pick first color • Move left to right, top to bottom • Pick neighborhood that matches best
Texture Synthesis by Analogy Template Synthesis Target • Randomly pick first color • Move left to right, top to bottom • Pick neighborhood that matches best
Texture Synthesis by Analogy • Large features require large neighborhood Source 5 x 5 7 x 7 9 x 9 6
Geometry Synthesis by Analogy • Geometry can be represented by matrix • Distance to next surface • Implicit representation • Positiveinside • Negative outside • Zero surface • Convert geometry into matrix • Apply synthesis by analogy to it 7
Geometry Synthesis by Analogy • Previous research in two dimensions 8 • Generalize from 2D to 3D • Improve speed
Editor • Build application • Graphical user interface • 3D display • Support all synthesis steps 9
Notes [1] Lord of the Rings. New Line Cinema. Beasts. Comp 460, Rice University. Midfield Terminal Complex. Southwest Florida International Airport. Dynamic Flight Simulator. Naval Warfare Center, Westminster, Penn. United States Navy. [2] Rollings, A., and Morris, D. Game Architecture and Design. [3] Terragen. Planetside Software. http://www.planetside.co.uk/terragen/ [4] DungeonMaker. Dr. P. Henningsen. http://dungeonmaker.sourceforge.net/
Notes [5] Illustration. Hive Assault. Comp 460, Rice University. [6] Wei, Li-Yi. Texture Synthesis by Fixed Neighborhood Searching. Ph.D. thesis. [7] Implicit Modeling Editor. Scott Schaefer, Rice University. [8] Actual synthesis result. Geometry Synthesis by Analogy. Mathias Ricken, Rice University (unpublished). [9] Illustration.
Extra Slides • Recursive Backtracking
Recursive Backtracking Unvisited neighbor to the north. Tear down wall! • Square grid • Start in one cell • Pick a neighboring cell that has never been reached before and tear down the wall to it • Remember previous cell • If no unvisited neighboring cell, backtrack No more unvisited neighbors, backtrack!