News Detail

9:44 a.m.

CG:SHOP Challenge 2025: Call for Problems

Since 2019, the CG:SHOP Challenge has been part of CG Week. The objective is to compute good solutions for instances of a challenging geometric optimization problem. The contributors with the most outstanding solutions are recognized at CG Week and invited to present their results, both at the event and in the proceedings.

Previous problems included:

  • Finding a simple polygon with minimum area (Challenge 2019)
  • Finding a subdivision with few convex pieces (Challenge 2020)
  • Coordinating the motion of a large set of objects (Challenge 2021)
  • Partitioning a set of edges into few plane subgraphs (Challenge 2022)
  • Minimum coverage by convex polygons (Challenge 2023)
  • Maximum polygon packing (Challenge 2024)

To broaden the scope of Challenge problems and ensure sufficient diversity, we are soliciting suitable problems for the Seventh Computational Geometry Challenge, to be part of CG Week 2025. Desirable properties are as follows.

  • The problem is of geometric nature.
  • The problem is of general scientific interest and has received previous attention.
  • Optimization problems tend to be more suitable than feasibility problems; suggestions for feasibility problems are also possible, provided they come with sufficiently fine-grained scoring.
  • Computing optimal solutions is difficult for instances of reasonable size.
  • This difficulty is of a fundamental algorithmic nature, and not only due to issues of encoding or access to sophisticated software or hardware.
  • Verifying feasibility of provided solutions is relatively easy.

To nominate a problem, please send the following by June 20 by email to

  • An informal description of the problem
  • A pointer to previous work, if any
  • Further useful information on the state of practical solutions, if any
  • Contact information of the nominator

The deadline is one week after this year’s CGWeek; nominations before CGWeek are strongly encouraged. Nominators may be contacted for further details; they may also be invited to participate in running the challenge.

The selected problem will be announced in early July, 2024.

We are looking forward to your contributions and welcome questions and comments!

Challenge Team and Advisory Board:

Bill Cook, Andreas Fabri, Sándor Fekete, Dan Halperin, Phillip Keldenich, Michael Kerber, Philipp Kindermann, Dominik Krupke, Joe Mitchell, Stefan Schirra, Kevin Verbeek