RepulsionPak: Deformation-Driven Element Packing with Repulsion Forces�Graphics Interface 2018�IEEE Transaction on Visualization and Computer Graphics 2019

Reza Adhitya Saputra

Craig S. Kaplan

Paul Asente

University of Waterloo

University of Waterloo

Adobe Research

Outline

• 1. Introduction

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• 2. Method

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• 3. result

1. Introduction

Element Packing

• Goal：
• Fill a container shape with deformable instances of geometric elements selected from a library, creating a 2D artistic composition.
• Applications：
• Advertising and product packaging

Example.

RepusionPak

• RepulsionPak is a technique to packing elements using a physical simulation, in which each element is represented by a mass-spring system called an element mesh.
• Forces don’t act directly on elements, but their mesh vertices.
• During the simulation, these mesh vertices are spread apart but remain connected using elastic springs, effectively creating an element representation that can bee packed and deformed.

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2. Method

System Overview

• Starts by preprocessing the elements, creating additional space around each to enforce the spacing distance, and fitting a triangle mesh over each element .
• Initial element placement.
• Perform a physics simulation on the meshes, making them simultaneously grow and repel other.
• Simulation ends when either the elements occupy a sufficient proportion of container area, or when some number of simulation steps fail to significantly reduce the negative space.
• Placing small secondary elements in large pockets of negative space.
• Final SVG output is created by using barycentric coordinates to map each each element’s paths from the element’s initial mesh into the deformed mesh produced through simulation.�

Preprocessing

• For each element

constructs mesh.

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Preprocessing

Simulation

Simulation

Simulation

Simulation

Simulation

Simulation

Element Growth

Stopping Criteria

• First, specifies the desired positive space ratio at which the simulation immediately terminates.

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• Second, we stop the simulation when the element meshes are no�longer able to maneuver enough to consume the remaining negative space.��

Secondary Elements

• seed the container with secondary elements by finding points that are far from any existing element mesh.�

(d) -> (e)

3. Result

Data and statistics for RepulsionPak results

Video