Felix RiestraandClaude Sonnet 5
78259c7aed
github.com/HakanSeven12/OpenCADStudio discussion #1052: constructing a 3-4-5 right triangle by drawing two circles (radius 3 and 4, centers 5 apart) and using OSNAP Intersection to find their crossing points gave measured side lengths that didn't match the entered radii. OSNAP's Intersection snap found candidate points by sweeping line segments from each wire's *tessellated* polyline approximation, never the entity's real geometry. Circles feeding the resident wire set always tessellate at a fixed 48 segments (Scene::resident_wires_for passes wpp=None deliberately, to avoid re-tessellating on every camera pan/zoom) regardless of radius or zoom — so every circle/arc/ellipse intersection snap was already off by construction, not just at extreme zoom levels. Arcs, ellipses, and splines have the same problem via their own fixed-angle tessellation. Added an exact intersection path that bypasses tessellation entirely, used by both call sites in the Intersection-snap code (the indexed/ local fast path and the brute-force wire-pair fallback), falling back to the original tessellated sweep for anything it can't resolve: - exact_circle_intersections: closed-form circle/circle intersection for any pair of Circle/Arc entities (frame-independent — each side's own arc sweep is checked against its own native axis, so two arcs in differently rotated coordinate frames still resolve correctly). - exact_curve_intersections: a more general path for anything involving a line or an ellipse — embeds both entities into a shared working plane and dispatches to cadkernel::geom2d::intersect (an exact/tolerance-converged solver already vendored in this repo's own dependency but previously unused for this purpose). Handles a reflection hazard the naive version would miss: when an entity's own normal is anti-parallel to the shared embedding frame's normal, the mapping mirrors the parametrization and reverses which physical arc a [start, end] range refers to — both the Arc and PlanarEllipse branches detect this and swap start/end to compensate. The only remaining case still going through the tessellated sweep is a compound polyline chain with a bulge segment (not a single recognized curve — it would need its own per-segment bookkeeping this pass doesn't add). 12 new tests, including the reported 3-4-5 case verified against the exact expected crossing points, arcs in differently rotated frames, and the anti-parallel-normal reflection case for both Arc and Ellipse (independently verified via a Python script for exact precision). Co-Authored-By: Claude Sonnet 5 <noreply@anthropic.com>
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Open CAD Studio
Open-source 2D drafting and 3D modeling for desktop and web, built with Rust.
Launch the web app · Download the desktop app · Join the discussion
Overview
Open CAD Studio is a cross-platform application for technical drawing, layout work, and solid modeling. It reads and writes DWG and DXF drawings natively, with a shared editing core across the desktop and browser versions.
The project is under active development. Keep backups of important production drawings and report reproducible problems through GitHub Issues.
Highlights
- Native drawing workflow — open, edit, recover, and save DWG and DXF files without a conversion service.
- Precise 2D drafting — lines, polylines, curves, splines, hatches, object snaps, tracking, layers, blocks, and external references.
- Documentation tools — text, dimensions, leaders, tolerances, tables, model space, paper space, viewports, and plot styles.
- Kernel-backed 3D modeling — solid primitives, extrusion, revolution, sweep, loft, Boolean operations, and ACIS entity tessellation.
- GPU rendering — accelerated 2D and 3D viewports through
wgpu, with orthographic and perspective cameras. - Extensible workflows — native plugins, command scripts, headless conversion, and a line-based JSON automation API.
File workflows
| Format or workflow | Support |
|---|---|
| DWG | Read and write; versioned save targets from R14 through 2018 |
| DXF | Read and write; versioned save targets from R14 through 2018 |
| BAK / SV$ | Open drawing backups and autosave files |
| OBJ | Import polygon meshes |
| LandXML | Import CgPoint survey points |
| STL | Export 3D mesh data |
| STEP AP203 | Export 3D mesh data |
| Plot layouts and selected geometry on desktop | |
| CSV | Extract entity property data |
| CTB / STB | Load and edit plot style tables |
Desktop or web
Use the web app for immediate access with no installation. Drawings are selected through the browser and saved as local downloads.
Use the desktop application for native file associations, file-manager thumbnails, system printing, PDF output, external plugins, command scripts, and headless automation. Release builds are available for Windows, Linux, and Apple Silicon macOS.
Install
Download all current packages from the latest release.
Windows
Choose one of these signed x86-64 packages:
OpenCADStudio-*-windows-x86_64-installer.msi— recommended installer with Start Menu shortcuts, DWG/DXF file associations, and drawing thumbnails.OpenCADStudio-*-windows-x86_64-portable.exe— standalone application; no installation required.
Linux
Download the x86-64 AppImage, make it executable, and run it:
chmod +x OpenCADStudio-*-linux-x86_64.AppImage
./OpenCADStudio-*-linux-x86_64.AppImage
macOS
The published macOS package supports Apple Silicon:
- Download
OpenCADStudio-*-macos-arm64.dmg. - Open the image and drag
OpenCADStudio.appinto Applications. - If Gatekeeper blocks the first launch, approve the app from System Settings → Privacy & Security.
The application is ad-hoc signed but is not currently notarized by Apple.
Languages
Open CAD Studio can follow the system language or use any of these 21 interface languages:
Arabic · Brazilian Portuguese · Bulgarian · Czech · Dutch · English · Finnish · French · German · Greek · Hindi · Hungarian · Italian · Japanese · Korean · Polish · Russian · Simplified Chinese · Spanish · Traditional Chinese · Turkish
Change the language from the application settings. The browser version also uses the browser's preferred locale when System is selected.
Build from source
Desktop
Requirements:
- Git
- Current stable Rust toolchain
- Platform graphics and font development libraries
On Ubuntu or Debian, install the native dependencies with:
sudo apt update
sudo apt install libgl1-mesa-dev libx11-dev libxcursor-dev libxi-dev \
libxrandr-dev libxkbcommon-dev libwayland-dev libfontconfig1-dev \
libfreetype6-dev
Then build and run:
git clone https://github.com/HakanSeven12/OpenCADStudio.git
cd OpenCADStudio
cargo build --release --bin OpenCADStudio
The resulting binary is written to target/release/OpenCADStudio (OpenCADStudio.exe on Windows).
Web
Install the WebAssembly target and build tools once:
rustup target add wasm32-unknown-unknown
cargo install trunk wasm-bindgen-cli
Start the development server:
trunk serve
Automation
The desktop binary supports one-shot conversion, a persistent headless server, and a client-neutral MCP endpoint for AI applications:
OpenCADStudio --export input.dwg output.dxf
OpenCADStudio --serve
OpenCADStudio --serve --port 4242
OpenCADStudio --mcp
The automation server exchanges one JSON object per line over standard input/output or a local TCP socket. The self-contained MCP endpoint exposes the live desktop editor through the same tools to every compatible client. To connect a client, configure it to launch OpenCADStudio --mcp. See the MCP control guide.
Plugins
Desktop plugins run in separate processes and communicate with the host through the versioned plugin API. The browser build does not load native plugins.
Project documentation
Contributing
Bug reports, focused pull requests, translations, documentation improvements, and plugin contributions are welcome.
- Search existing issues before opening a new report.
- Use Discussions for questions and ideas.
- Report vulnerabilities privately by following the security policy.
Application translations live in locales/*/opencadstudio.ftl; source labels map through
src/locale_catalog.rs. After editing translations, run python3 scripts/export-locales.py
to refresh web and desktop packaging labels. Validate with python3 scripts/test_site.py
and cargo test --lib i18n::tests.
Project growth
Stars
Release downloads
Support the project
If Open CAD Studio helps your work, support continued development through GitHub Sponsors or Patreon.
License
Open CAD Studio is distributed under the GNU General Public License v3.0.