Sculpting multi-dimensional nested structures

Lucian Stanculescu a,b

Raphaëlle Chaine a

Marie-Paule Cani b,c

Karan Singh d

a LIRIS, University of Lyonb LJK, University of Grenoble

c Inria, Grenobled University of Toronto

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Contents

1. Introduction

2. Design goals

3. Multi-dimensional nested structure

4. Sculpting system

5. Conclusion

1. Introduction

2. Design goals

3. Multi-dimensional nested structure

4. Sculpting system

5. Conclusion

Features on objects:• regions – appearance and function• curve networks – boundaries, creases• points – corners

Goal: create, maintain, edit features during sculpting

Features on objects:• regions – appearance and function• curve networks – boundaries, creases• points – corners

Goal: create, maintain, edit features during sculpting

1. Introduction

3

Related work:

• Spatial deformations

• Features have to be maintained externally[Sederberg ’86, Wires, Singh ’98, von Funck ’06]

• Professional sculpting applications emulate sharp features[ZBrush, 3D Coat]

Related work:

• Spatial deformations

• Features have to be maintained externally[Sederberg ’86, Wires, Singh ’98, von Funck ’06]

• Professional sculpting applications emulate sharp features[ZBrush, 3D Coat]

1. Introduction

4

1. Introduction

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

5

Related work:

• Object-aware deformations

• Implicit – problems maintaining features[Ferley 01]

• Variational – topologically invariant features[iWires, Gal 09]

• Part-based modelerscomplementary to free-form sculpting[Meshmixer, Schmidt ’10]

• Curve-network based modelersshape from features[FiberMesh, Nealen ’07]

Related work:

• Object-aware deformations

• Implicit – problems maintaining features[Ferley 01]

• Variational – topologically invariant features[iWires, Gal 09]

• Part-based modelerscomplementary to free-form sculpting[Meshmixer, Schmidt ’10]

• Curve-network based modelersshape from features[FiberMesh, Nealen ’07]

1. Introduction

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

6

GOALS:

Concurrent deformation of objects and features.

Maintain or change topology of both.

GOALS:

Concurrent deformation of objects and features.

Maintain or change topology of both.

6

2. Design goals. Pseudo-physical behavior

3. Multi-dimensional nested structure

How to handle features in a discrete world?Embed features in a discrete cell complex.

How it evolves under deformation?Convergent updating scheme w. basic operations on cells.

DEFINITIONMulti-dimensional nested structure =cell complex partitioning n-D space into n-D cells, bounded by (n-1)-D cells and so on to lower dimensions, with some boundaries marked as features.

How to handle features in a discrete world?Embed features in a discrete cell complex.

How it evolves under deformation?Convergent updating scheme w. basic operations on cells.

DEFINITIONMulti-dimensional nested structure =cell complex partitioning n-D space into n-D cells, bounded by (n-1)-D cells and so on to lower dimensions, with some boundaries marked as features.

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3. MDNS. General atomic operations on cells

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No features

Large deformations > cell complex update• Improve fidelity of the shape• Handle self-intersections - insertions

No features

Large deformations > cell complex update• Improve fidelity of the shape• Handle self-intersections - insertions

3. MDNS. Feature handling in updating scheme

10

Hierarchical processing

• Bottom-up step: restore geometric quality

• Top-down step: handle self-intersections

Hierarchical processing

• Bottom-up step: restore geometric quality

• Top-down step: handle self-intersections

3. Multi-dimensional nested structure

11

4. Sculpting system

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

12

Simplification:• Quasi-uniform mesh with features

[Freestyle ’11]

Operations (with features):• Edge split : cell division• Edge collapse : cell collapse• Edge flip : cell fusion + cell division• Vertex insertion : cell divisions + cell fusion

• Edge flip : stability & quality• Vertex insertion : intersection

Simplification:• Quasi-uniform mesh with features

[Freestyle ’11]

Operations (with features):• Edge split : cell division• Edge collapse : cell collapse• Edge flip : cell fusion + cell division• Vertex insertion : cell divisions + cell fusion

• Edge flip : stability & quality• Vertex insertion : intersection

5. Conclusion

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

13

Represent and deform shapes with nested features

Preserve or change properties of the deformed shape

Sculpting application adapted to creative workflow

Represent and deform shapes with nested features

Preserve or change properties of the deformed shape

Sculpting application adapted to creative workflow

5. Conclusion

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

Features on objects:

• regions – appearance and function

• curve networks – boundaries, creases

• points – corners

14

Future work:

• Sliders• Features glide on support

• Non-orientable structures

• Base structure for other methods• Features control the shape of support

Future work:

• Sliders• Features glide on support

• Non-orientable structures

• Base structure for other methods• Features control the shape of support