LoopDraw: a Loop-Based Autoregressive Model for Shape Synthesis and Editing

TL;DR

LoopDraw introduces a novel shape representation using hierarchical sequences of cross-sectional loops, enabling intuitive and effective autoregressive shape synthesis and editing, offering an alternative to existing 3D shape representations.

Contribution

The paper proposes a new loop-based shape representation that facilitates autoregressive synthesis and editing, contrasting with traditional local primitive manipulations.

Findings

Loops enable significant structural shape changes through simple manipulations.

The hierarchy of loops improves shape organization and editing capabilities.

Loop-based representation is intuitive for both computational processing and user interaction.

Abstract

There is no settled universal 3D representation for geometry with many alternatives such as point clouds, meshes, implicit functions, and voxels to name a few. In this work, we present a new, compelling alternative for representing shapes using a sequence of cross-sectional closed loops. The loops across all planes form an organizational hierarchy which we leverage for autoregressive shape synthesis and editing. Loops are a non-local description of the underlying shape, as simple loop manipulations (such as shifts) result in significant structural changes to the geometry. This is in contrast to manipulating local primitives such as points in a point cloud or a triangle in a triangle mesh. We further demonstrate that loops are intuitive and natural primitive for analyzing and editing shapes, both computationally and for users.