2022-05410 - Internship - Rationalization of CAD assemblies (Computer Graphics, Computer Aided Design, Optimization)
Le descriptif de l’offre ci-dessous est en Anglais

Type de contrat : Stage

Niveau de diplôme exigé : Bac + 5 ou équivalent

Fonction : Stagiaire de la recherche

A propos du centre ou de la direction fonctionnelle

The Inria Sophia Antipolis - Méditerranée center counts 34 research teams as well as 7 support departments. The center's staff (about 500 people including 320 Inria employees) is made up of scientists of different nationalities (250 foreigners of 50 nationalities), engineers, technicians and administrative staff. 1/3 of the staff are civil servants, the others are contractual agents. The majority of the center’s research teams are located in Sophia Antipolis and Nice in the Alpes-Maritimes. Four teams are based in Montpellier and two teams are hosted in Bologna in Italy and Athens. The Center is a founding member of Université Côte d'Azur and partner of the I-site MUSE supported by the University of Montpellier.

Contexte et atouts du poste

Our group works on various topics related to computer-aided design (CAD) and computer graphics (https://team.inria.fr/graphdeco/).

Many objects that surround us are created in CAD by assembling simple parts, and the cost of fabricating and repairing these objects highly depends on the availability of their constituent parts. Creating objects such that they are composed of standard parts is a difficult design task, akin to solving puzzles with pieces taken from a very large catalogue of items. Our goal is to ease this task by assisting designers in creating families of objects composed of the same parts. We call this problem assembly rationalization, as the goal is to make a set of assemblies be more efficient by sharing their parts. A similar notion of rationalization has been studied in the related domain of architectural design [1].

This internship may be extended to a PhD

See more details here: http://www-sop.inria.fr/members/Adrien.Bousseau/stages/CADAssembly.pdf

Mission confiée

We will formulate this problem as an optimization, where the input is a set of assemblies created using Computer-Aided Design (CAD), and the output is a new set that best satisfies two competing objectives:

  • Each assembly should remain as similar as possible to its initial state,
  • All assemblies should share as many parts as possible.

Solving this problem requires identifying similar parts across assemblies, and modifying the dimensions of these parts until they are identical. Importantly, these geometric modifications should maintain the functionality of the original assemblies, which induces complex dependencies between parts in each assembly. The resulting optimization is likely to include both discrete variables (which parts can be made the same) and continuousvariables (what dimensions should the parts takes to be identical), along with constraints ensuring preservation of functionality (alignments, contacts).

As a first step, we will formalize and develop the optimization procedure by working on furniture assemblies, which we could generate artificially by defining simple parametric furniture models, such as closets and shelves [2,3]. If time permits, we will then consider the extension of the method to more diverse and realistic assemblies from recent CAD datasets [4,5].

Principales activités

The main activity will consist in studying related algorithms in shape optimization [1,2,3], and proposing novel optimization algorithms adapted to the new problem of optimizing parts across several shapes.

A second activity will consist in studying recent datasets of CAD assemblies [4,5] and developping tools to apply the algorithm on such data.


[1] Paneling Architectural Freeform Surfaces
Michael Eigensatz, Martin Kilian, Alexander Schiftner, Niloy J. Mitra, Helmut Pottmann,
Mark Pauly

[2] Towards Zero-Waste Furniture Design
Bongjin Koo, Jean Hergel, Sylvain Lefebvre, Niloy J. Mitra
TVCG 2017

[3] Guided Exploration of Physically Valid Shapes for Furniture Design
Nobuyuki Umetani, Takeo Igarashi, Niloy J. Mitra

[4] JoinABLe: Learning Bottom-up Assembly of Parametric CAD Joints
Karl D.D. Willis, Pradeep Kumar Jayaraman, Hang Chu, Yunsheng Tian, Yifei Li, Daniele Grandi, Aditya Sanghi, Linh Tran, Joseph G. Lambourne, Armando Solar-Lezama, Wojciech Matusik

[5] AutoMate: A Dataset and Learning Approach for the Automatic Mating of CAD Assemblies
Benjamin Jones, Dalton Hildreth, Duowen Chen, Ilya Baran, Vova Kim, and Adriana Schulz


Python, C++, 3D Graphics
Optimization libraries


  • Subsidized meals
  • Partial reimbursement of public transport costs
  • Leave: 7 weeks of annual leave + 10 extra days off due to RTT (statutory reduction in working hours) + possibility of exceptional leave (sick children, moving home, etc.)
  • Possibility of teleworking (after 6 months of employment) and flexible organization of working hours
  • Professional equipment available (videoconferencing, loan of computer equipment, etc.)
  • Social, cultural and sports events and activities
  • Access to vocational training
  • Social security coverage
  • Employer's contribution to mutual insurance (subject to conditions)