# Snaxels on a Plane

## TL;DR

This paper adapts snaxel active contours to robustly extract and organize mesh contours into closed loops for stylized vector art, animation tracking, and efficient 2D SVG conversion.

## Contribution

It introduces a novel application of snaxels for contour extraction, organization, and animation tracking on meshes, enabling improved stylized rendering and dynamic vector graphics.

## Key findings

- Robust contour extraction on meshes using snaxels.
- Effective tracking of contours during mesh animation.
- Conversion of 3D mesh contours into 2D SVG animations.

## Abstract

While many algorithms exist for tracing various contours for illustrating a meshed object, few algorithms organize these contours into region-bounding closed loops. Tracing closed-loop boundaries on a mesh can be problematic due to switchbacks caused by subtle surface variation, and the organization of these regions into a planar map can lead to many small region components due to imprecision and noise. This paper adapts "snaxels," an energy minimizing active contour method designed for robust mesh processing, and repurposes it to generate visual, shadow and shading contours, and a simplified visual-surface planar map, useful for stylized vector art illustration of the mesh. The snaxel active contours can also track contours as the mesh animates, and frame-to-frame correspondences between snaxels lead to a new method to convert the moving contours on a 3-D animated mesh into 2-D SVG curve animations for efficient embedding in Flash, PowerPoint and other dynamic vector art platforms.