geometry synthesis mathias ricken rice undergraduate scholar program november 11, 2003
TRANSCRIPT
Geometry Synthesis
Mathias Ricken
Rice Undergraduate Scholar Program
November 11, 2003
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OverviewComputer-Generated Geometry
Uses Creation
Previous Work Landscapes Mazes Problems
Geometry Synthesis Parametric synthesis Synthesis by analogy
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Computer-Generated Geometry1
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Creating GeometryHand-Crafted
Computer games
1 Man-Year for 40 hours of game play 2
Automation Lower costs Better training Higher replay value
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Landscapes
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Landscapes
Filters Smoothen or roughen landscape Add rivers and lakes
Height Map Matrix of numbers
e.g. one per square foot Numbers
Elevation
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Mazes
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Mazes
Recursive Backtracking Regular grid 2-Dimensional
Creates perfect mazes All cells connected in
exactly one way No loops
algorithm explained in extra slides
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ProblemsLandscapes
Large scale, but low detail Only natural, not artificial
Mazes 2-dimensional Small scale Not reminiscent of human
architecture
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Proposed Project
Create meaningful geometry Similar to human architecture 3-dimensional High detail
Algorithms Parametric synthesis Synthesis by analogy
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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
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Parametric Synthesis
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Generalize 3D, not 2D Not grid-based
Examples of Parameters Frequencies Dimensions Angles Alignment
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Parametric Synthesis
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Synthesis by Analogy
Automatically enhance bare geometry created by parametric synthesis Use design templates Add colors, patterns, details
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Texture Synthesis by AnalogyGiven 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
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Texture Synthesis by AnalogyTemplate Synthesis Target
1. Randomly pick first color
2. Move left to right, top to bottom
3. Pick neighborhood that matches best
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Texture Synthesis by AnalogyTemplate Synthesis Target
1. Randomly pick first color
2. Move left to right, top to bottom
3. Pick neighborhood that matches best
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Texture Synthesis by Analogy
Large features require large neighborhood
Source 5 x 5 7 x 7 9 x 9
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Geometry Synthesis by Analogy
Geometry can be represented by matrix Distance to next surface Implicit representation
Positive inside Negative outside Zero surface
Convert geometry into matrixApply synthesis by analogy to it
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Geometry Synthesis by AnalogyPrevious research in two dimensions
Generalize from 2D to 3D
Improve speed
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Editor
Build application Graphical user interface 3D display Support all synthesis steps
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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/
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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.
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Extra Slides
Recursive Backtracking
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Recursive Backtracking 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!
Unvisited neighbor to the
north. Tear down wall!