Systems

Qt/OpenGL viewer

Windows, Linux and macOS desktop app to load and inspect meshes.

Done Sprint S26-S27 · 13 points

In short, no jargon for non-developersRead the summaryClose

What it is: An application to install on your computer (Windows, macOS or Linux) to open a 3D object, turn it around and read its properties.
What it is for: This is the form of the engineering software used every day, delivered ready to install.
What it shows: Taking a desktop application all the way to delivery, with an installer for each of the three systems.

Source code

How the pieces fit together

lib-c (reads the files) → MeshModel (normals, colours): mesh read
Window (Qt Widgets, Linguist) → MeshModel (normals, colours): opens
MeshModel (normals, colours) → Renderer (OpenGL 3.3, GLSL)
Window (Qt Widgets, Linguist) → Renderer (OpenGL 3.3, GLSL): draws
Window (Qt Widgets, Linguist) → Camera (orbital, no OpenGL)
Camera (orbital, no OpenGL) → Renderer (OpenGL 3.3, GLSL): view, zoom
MeshModel (normals, colours) → Picking (ray casting on the CPU): click: vertex or face

The viewer at work

A Qt 6 and OpenGL desktop application for Windows, Linux and macOS: it reads the file with the portfolio's C library and computes its topology with the topologie project, then shows the mesh and its invariants.

The viewer's window: on the left a 3D torus on a dark grey background, its triangles drawn, coloured from blue (negative curvature, inside) to red (positive, outside); on the right the Topology panel: 1,152 vertices, 3,456 edges, 2,304 faces, one component, no boundary, orientable manifold, Euler characteristic 0, genus 1, then the Gaussian curvature scale. — Screenshot taken by the application itself (--screenshot option), on a virtual screen, with Mesa's software OpenGL.

To run it at home (Qt 6.5 or later, CMake, a C++20 compiler):

cd projects/qt
cmake -S . -B build && cmake --build build
./build/qtviewer --lang en sample:torus        # a built-in example, coloured by curvature with the C key
./build/qtviewer ../lib-c/tests/data/cube.obj      # an OBJ, PLY or STL file

Ready-to-run programs (Windows folder, macOS disk image, Linux AppImage, unsigned), built and launched once by the CI, kept for 30 days: artifacts of the qt workflow

Tech stack

C++
Qt
OpenGL
Qt Test

Who does what

C++: The C++20 application: mesh model, camera and ray-cast picking, testable without OpenGL; reading by lib-c, topology by the topology project.
Qt: Windows, menus, panels, drag and drop and the French translation (Qt Linguist); windeployqt, macdeployqt and AppImage for the executables.
OpenGL: The 3D rendering (OpenGL 3.3, GLSL shaders): two-sided lighting, wireframe, curvature colours.
Qt Test: The tests, including an off-screen rendering read back pixel by pixel, on Linux, Windows and macOS.

Definition of Done

Code reviewed, diff by diff
Unit and integration tests green
Green CI on Linux, Windows and macOS when compiled
README, REVIEW.md and DECISIONS.md up to date
Texts in French and English
Demo deployed and tested on mobile