Transcript Feature-Based Mesh Editing

Feature-Based Mesh Editing
Qingnan Zhou 1
Tino Weinkauf 1,2
Olga Sorkine 1,3
1 NYU
2
MPII Saarbrücken
3 ETH Zürich
Deformation
Deformation
Deformation
Detail
Preserving
[Sorkine et al. ARAP Surface Modeling, SGP 07]
Deformation
Structure
Preserving
Detail
Preserving
[Gal et al., iWires, SIGGRAPH 2009]
Deformation
Original
Structure
Preserving
Detail
Preserving
Feature
Preserving
[Sorkine et al. ARAP
Surface Modeling, SGP 07]
Our result
Feature-Based Mesh Editing
Input
Feature Extraction
Result of feature editing
Features
• What are features?
– In words, features are where surface normal
changes abruptly.
– In pictures:
Features
• What are features?
[Hildebrandt et al., Smooth Feature Lines, SGP05]
– In math: local minimum and maximum of principle
curvatures in their corresponding directions.
Local maximum
Cross Section
Features
• What are features?
[Hildebrandt et al., Smooth Feature Lines, SGP05]
– In math: local minimum and maximum of principle
curvatures in their corresponding directions.
Extremality:
– Zeros of emax that satisfy the following (similar
constraints apply to emin)
Salient
constraints:
Features
• What are features?
– In practice:
Input
Valley lines (blue)
Zeros of emin
Ridge lines (yellow)
Zeros of emax
Feature-Preserving Optimization
• Idea: if curvature values are preserved, so are
their local minima and maxima, and so are the
features, right?
Feature-Preserving Optimization
• Idea: if curvature values are preserved, so are
their local minima and maxima, and so are the
features, right?
– Answer: possibly.
– Concern 1: what about principle curvature
directions?
– Concern 2: non-convex energy?
Feature-Preserving Optimization
Energy Formulation:
Feature-Preserving Optimization
Energy Formulation:
Curvature
Preservation:
Feature-Preserving Optimization
Energy Formulation:
Conformality:
Feature-Preserving Optimization
Energy Formulation:
Positional
constraint:
Feature Manipulation
• Feature-preserving deformation:
Original
[Sorkine et al.
ARAP Surface
Modeling, SGP 07]
Our result: original
curvature preserved
Feature Manipulation
• Feature-preserving deformation:
Original
[Sorkine et al.
ARAP Surface
Modeling, SGP 07]
Our result: original
curvature preserved
Feature Manipulation
• Feature smoothing and sharpening:
Original
Features
Our result
Feature Manipulation
• Feature smoothing and sharpening:
Original
Original
Features smoothed
Features
sharpened
Feature Manipulation
• Feature creation:
Original
Our result
Feature Manipulation
• Feature creation:
Original
User drawn features
Red: ridge
Blue: valley
Our result
Summary
• We have presented a feature-based deformation
system.
• Our experiments give optimistic results.
• Future work:
– Check for conflicting constraints.
– Theoretic support of the idea.
– Try meshes with less pronounced features.