Skip to main content
16-Pearl
January 1, 2026
Question

Mathcad Community Challenge January 2026: The Art Gallery Problem

  • January 1, 2026
  • 5 replies
  • 495 views

Happy New Year!

 

This month’s challenge is inspired by recent events: the October 2025 Louvre heist in Paris France.

Cour_Marly,_Musée_du_Louvre_from_Paris.jpg

 

Using Mathcad Prime, solve any or all of the following challenges:

Challenge 1 (Polygonal): find the minimum number of guards necessary to cover 100% of the following polygonal space.

To be unobtrusive, the guards must be placed at vertices. The guards are inside the museum. Assume that the guards can turn their necks and bodies to see everywhere around that point that is not blocked by a wall. The guards have excellent vision and can see everything clearly between them and a wall.

 

Art Gallery Polygon v2.png

 

Challenge 2 (Graphing): using the plotting and charting capabilities of Mathcad, depict the placement of the guards and their zones of coverage.

 

Challenge 3 (Orthogonal Variant): find the minimum number of guards for the following art gallery.

 

Art Gallery Orthogonal v2.png

 

Challenge 4 (Graphing): Depict the placement of the guards and their zones of coverage for the orthogonal variant.

 

Challenge 5 (Basher Tarr variant): You are the tech expert for the Ocean’s 11 crew. Your job is to remove one guard to leave the maximum amount of exposed area. Which guard do you remove in either of the scenarios?

Oceans 11.jpg

 

Note: Creo Parametric 7.0 CAD part models and a Mathcad Prime 10 worksheet have been attached. If people want to incorporate Creo into their solution, feel free. The Mathcad worksheet contains matrices of the vertices.

 

Find the Mathcad Community Challenge Guidelines here!

 

 

5 replies

25-Diamond I
January 1, 2026

There seems to be an error in the vertices table. Although a number of dimensions are missing in the Creo screenshot, fortunately the relevant one is specified:

Werner_E_0-1767281697275.png

 

 

19-Tanzanite
January 5, 2026

Here's my simple starter for the polygonal version only.

January2026Challenge_AS_1.png

 

Alan

19-Tanzanite
January 9, 2026

Here's a similar approach to the Orthogonal case:

January2026Challenge_AS_2.png

 

As before, the positions of the guards is not unique, and I haven't indicated overlapping fields of vision.

 

In both cases I just used a visual approach, as I haven't figured out an algorithmic one.  I'd be interested to see if there is one.

It's not clear to me if the question is looking for a positioning with minimal overlapping fields of vision - if so, I haven't tried to find that!

I guess the last part (Challenge 5) will require the actual calculation of areas - something I've tried to avoid so far!

 

Alan

18-Opal
January 23, 2026

While it may be good for the museum for no one to try Challenge 5, it's way more fun if someone does try it! (And good as a mental exercise.)

 

Anyway, January surprisingly ends in a week. Maybe for those snowed in the United States this weekend and looking for a wholesome activity to do, the challenge would be fun to try solving (if you have power).

ttokoro
21-Topaz I
21-Topaz I
January 30, 2026

Just how to paint the answers.

 

image.pngimage.pngimage.png

t.t.
ttokoro
21-Topaz I
21-Topaz I
January 31, 2026
ttokoro
21-Topaz I
21-Topaz I
January 31, 2026
18-Opal
March 2, 2026

https://www.ptc.com/en/blogs/cad/mathcad/community-challenge-art-gallery-problem

 

Thanks for your participation in the January challenge!

 

Check out the March challenge now. 🙂