Introducing Bidirectional Programming in Constructive Solid Geometry-Based CAD

TL;DR

This paper introduces bidirectional programming for CSG-based CAD tools, enabling seamless editing through direct manipulation and code, thus improving user interaction and consistency in 3D modeling.

Contribution

It presents the concept of bidirectional programming in CSG CAD, supported by a prototype implementation that enhances user flexibility and model consistency.

Findings

User interviews informed the design of bidirectional editing

Prototype demonstrates effective synchronization between view and code

Bidirectional approach improves usability for programmatic CAD users

Abstract

3D Computer-Aided Design (CAD) users need to overcome several obstacles to benefit from the flexibility of programmatic interface tools. Besides the barriers of any programming language, users face challenges inherent to 3D spatial interaction. Scripting simple operations, such as moving an element in 3D space, can be significantly more challenging than performing the same task using direct manipulation. We introduce the concept of bidirectional programming for Constructive Solid Geometry (CSG) CAD tools, informed by interviews we performed with programmatic interface users. We describe how users can navigate and edit the 3D model using direct manipulation in the view or code editing while the system ensures consistency between both spaces. We also detail a proof-of-concept implementation using a modified version of OpenSCAD.