A python plot3D library for reading, writing, finding connectivity, and post processing for Plot3D data files.
To install simply do a pip install plot3d
Building the docs
- From the repo root, run pip install uv (if you don't already have uv) then uv sync --extra docs (and commit the refreshed uv.lock) to capture the new Sphinx dependencies.
- Build locally with uv run sphinx-build -b html docs docs/_build/html or use uv run sphinx-autobuild for live previews.
- Push the branch to main, then enable GitHub Pages (Settings → Pages → “GitHub Actions”) so the new workflow can deploy your merged Sphinx docs automatically.
Metis is used to group the blocks to be evaluated. So say you have 1000 blocks and 8 CPU. The blocks are split up and sent to the CPU or GPU. The split is done with weighting to block size and connectivity this way each processor is evaluating similar number of nodes. Plot3D Library will work without metis but metis functionality wont be available.
Partitioning is backed by metis-rs, a pure Rust reimplementation of METIS with Python bindings. It ships as a prebuilt wheel, so pip install plot3d (which pulls in metis-rs) is all that's needed on Linux, Mac, and Windows — no separate METIS install, no compiler, and no METIS_DLL/LD_LIBRARY_PATH setup required.
Reading Writing and Viewing Plot3D files
Read/Write File Formats (Binary, ASCII, Fortran, Endianness)
Periodicity with axially rotated and copied blocks
Flatten a mesh into a finite-volume graph, and solve on it: a converging-diverging duct
(this notebook's graph comes from plot3d.flatten_mesh — an unstructured, multi-block 3D finite-volume graph; not to be confused with plot3d.meridional_flatten, a different, 2D axisymmetric collapse used internally by the same duct example's Euler solver stage)
Cross-plane connectivity: why some face matches need more than lb/ub
Learning Bash for Automating Tasks
Never use jupyter notebook unless you are done with your .py file and want to demo code. Jupyter is painful for debugging.
- Better comments https://marketplace.visualstudio.com/items?itemName=aaron-bond.better-comments
- Python syntax highlighting https://marketplace.visualstudio.com/items?itemName=ms-python.vscode-pylance
- Remote Development https://code.visualstudio.com/docs/remote/remote-overview
- Python doc string generator https://marketplace.visualstudio.com/items?itemName=njpwerner.autodocstring
| Name | Position | Dates | Contribution | |
|---|---|---|---|---|
| Paht Juangphanich | Owner | 2021- | Creator | https://github.com/pjuangph |
| David Rigby | Advisor | Fall 2021 | Block splitting help | |
| Christopher Keokot | Intern | Fall 2021 | Plot3D ReactJS GUI | |
| Tim Beach | Advisor | Fall 2021 | Block splitting help |
connectivity_fast() finds matching faces between blocks and returns orientation data for each match. When two faces lie on different constant planes (e.g., a K-face connects to a J-face), the varying axes differ and an axis swap may be needed. This is encoded as a permutation_index (0–7) using 3 bits:
| Bit | Flag | Meaning |
|---|---|---|
| 0 | u_reversed |
Flip first varying axis |
| 1 | v_reversed |
Flip second varying axis |
| 2 | swapped |
Transpose u and v axes |
Each face match includes an orientation dict:
face_matches, outer_faces = connectivity_fast(blocks)
# Each match in face_matches has:
# match['orientation'] = {
# 'permutation_index': int, # 0-7
# 'plane': str, # 'in-plane' or 'cross-plane'
# 'permutation_matrix': list # 2x2 signed permutation matrix
# }The 8 permutation matrices are also available as plot3d.PERMUTATION_MATRICES.
- Face Orientation: Cross-Plane Connectivity — why cross-plane face connections need orientation flags beyond lb/ub, and how the 8-permutation system works
- Presentation (PowerPoint) — visual walkthrough of 2D→3D diagonal combinatorics
The rust version is available here. This version of the code is useful for creating CFD solvers in rust Plot3D-RS It has most of the functionality of the python version except for some of the GlennHT pre-processing code.
The development of this library was supported by NASA AATT (Advance Air Transport Technology). The development is supported by NASA Glenn LTE Branch. Anyone is welcome to contribute by submitting a pull request.