Graphics

cgvr.korea.ac.kr Graphics Lab @ Korea University

Model Construction

고려대학교 컴퓨터 그래픽스 연구실

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Model Construction

Interactive Modeling Tools CAD programs Subdivision surface editors

Scanning Tools CAT, MRI, laser, magnetic, robotic arm, etc.

Computer Vision Stereo, motion, etc.

Procedural Generation Sweeps, fractals, grammars

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Interactive Modeling Tools

User Constructs Objects with Drawing Program Menu commands, direct manipulation, etc. CSG, parametric surfaces, quadrics, etc.

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Interactive Modeling Tools

Example: Mechanical CAD

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Model Construction

Interactive Modeling Tools CAD programs, subdivision surface editors

Scanning Tools CAT, MRI Laser Range Scanning Magnetic, robotic arm

Computer Vision Stereo, motion, etc.

Procedural Generation Sweeps, fractals, grammars

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Scanning Tools

Acquire Geometry of Objects with Active Sensors CAT/MRI Laser range scanner Magnetic sensor Robotic arm Etc.

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Scanning Tools

Acquire Geometry of Objects with Active Sensors CAT/MRI Laser range scanner Magnetic sensor Robotic arm Etc.

Color

Depth

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Scanning Tools

Acquire Geometry of Objects with Active Sensors CAT/MRI Laser range scanner Magnetic sensor Robotic arm Etc.

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Scanning Tools

Acquire Geometry of Objects with Active Sensors CAT/MRI Laser range scanner Magnetic sensor Robotic arm Etc.

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Model Construction

Interactive Modeling Tools CAD programs Subdivision surface editors

Scanning Tools CAT, MRI, laser, magnetic, robotic arm, etc.

Computer Vision Stereo Motion

Procedural Generation Sweeps, fractals, grammars

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Computer Vision

Infer 3D Geometry from Images Stereo Motion Constraints Etc.

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Computer Vision

Infer 3D Geometry from Images Stereo Motion Constraints Etc.

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Computer Vision

Infer 3D Geometry from Images Stereo Motion Constraints Etc.

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Model Construction

Interactive Modeling Tools CAD programs, subdivision surface editors

Scanning Tools CAT, MRI, laser, magnetic, robotic arm, etc.

Computer Vision Stereo, motion, etc.

Procedural Generation Sweeps Fractals Grammars

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Model Construction

Goal: Describe 3D models algorithmically

Best for Models Resulting from ... Repeating processes Self-similar processes Random processes

Advantages: Automatic generation Concise representation Parameterized classes of models

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Sweep

Example: Seashells Create 3D polygonal surface models of seashells Sweep generating curve around helico-spiral axis

Helico-spiral definition:

i+1i

ri+1 ri r

zi+1 zi z

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Sweep

Generate Different Shells by Varying Parameters

Different helico-spirals Different generating curves

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Fractal

Defining Property: Self-similar with infinite resolution

Mandelbrot Set

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Fractal

Useful for Describing Natural 3D Phenomenon Terrain Plants Clouds Water Feathers Fur Etc.

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Fractal Generation

Deterministically Self-Similar Fractals Parts are scaled copies of original

Initiator: start with a shape Generator: replace subparts with scaled copy of original

Statistically Self-Similar Fractals Parts have same statistical properties as original

Initiator: start with a shape Generator: replace subparts with a self-similar random

pattern

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Deterministically Self-Similar Fractal

Useful for Creating Interesting Shapes

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Deterministically Self-Similar Fractal

Useful for Creating Interesting Shapes

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Statistically Self-Similar Fractal

Useful for Creating Mountains

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Statistically Self-Similar Fractal

Useful for Creating 3D Plants

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Grammar

Generate Description of Geometric Model by Applying Production Rules Useful for creating plants

Example:

Tree Branch Tree | Leaf

Branch Cylinder | [ Tree ]

C[CL]C[C[CL][CL]]C[[CL][CL]] C[*]C[*][*]

cgvr.korea.ac.kr

CGVR

Graphics Lab @ Korea University

Grammar

Useful for Creating Plants