A paper layout painted its whole canvas in the page colour, so the sheet had no visible edge — zooming out never reached one, because the surround was the same colour as the page. Floating viewports then painted themselves black over it. Both come from the same idea, that a viewport's canvas is a colour it can be handed. What lies behind a viewport depends on what the viewport is: - The full-canvas sheet shows the desk. `paper_bg_color` is the page, and the page is a bounded rectangle `paper_sheet_fill` already draws; using it for the canvas too erased the boundary between them. The desk is now its own colour, defined once in the scene and read by both the widget and the renderer, so the two cannot drift apart. - A floating viewport sits on that sheet and must paint no canvas at all. Handing it a transparent one does not work: the background shader returns an opaque colour whatever alpha it is given, so alpha zero came out black. Skipping the pass is the only way to ask for see-through, so `skip_background` now suppresses both the clear and the pass. It is part of the frame signature too — without that, a cached frame would keep showing the canvas the flag was just turned off for. Shading and fog still blend toward what is behind a floating viewport, which is the page, so the uniform keeps that colour even though nothing paints it. Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>
Open CAD Studio
OCS is a CAD application for 2D drafting and 3D modeling, built with Rust. Reads and writes DWG and DXF files natively. Also has a web version now!
OCS Web try it in the browser: https://hakanseven12.github.io/OpenCADStudio/
Features
File Formats
- DWG read/write (R13 through R2018)
- DXF read/write (R13 through R2018)
- STL export (
STLOUT/EXPORTSTL) - STEP AP203 export (
STEPOUT) - OBJ import (
IMPORTOBJ) - PDF export (plot layouts to PDF)
- WBLOCK — write selected entities or a block to an external file
- XREF — attach, reload, and auto-resolve external references
2D Drafting
| Command | Description |
|---|---|
LINE, PLINE, RECTANG, POLYGON |
Basic geometry |
CIRCLE, ARC, ELLIPSE, SPLINE |
Curves |
HATCH, HATCHEDIT |
Hatch fills with pattern, scale, angle editing |
OFFSET, TRIM, EXTEND, FILLET |
Modify geometry (supports lines, arcs, ellipses, polylines, splines) |
BREAK, STRETCH, LENGTHEN |
Shape editing |
ARRAY, MIRROR, MOVE, COPY, ROTATE, SCALE |
Transformations |
EXPLODE |
Explode blocks, dimensions, polylines, mlines |
DDEDIT |
Double-click text editing |
MASSPROP |
Area, perimeter, centroid of selected entities |
3D Modeling
| Command | Description |
|---|---|
BOX, SPHERE, CYLINDER |
Solid primitives |
EXTRUDE, REVOLVE |
Profile-based solids |
LOFT |
Ruled-surface loft through cross-sections |
SWEEP |
Sweep a profile along a path |
ARRAY3D |
3D array |
| ACIS tessellation | Renders 3DSOLID, REGION, and BODY entities |
Annotations & Dimensions
- Dimensions: Linear, Aligned, Angular, Radial, Diameter, Ordinate — with full
DIMSTYLEsupport (DIMASZ,DIMSCALE,DIMEXO,DIMEXE, and more) - Text:
MTEXT,TEXT,DTEXTwith font browser (STYLE DIALOG) - Leaders:
MLEADERwith straight and spline path types;MLEADERSTYLEmanager - Tolerances: GD&T feature control frames
- Tables:
TABLEentity render;TABLESTYLEmanager - MLine:
MLINEentity withMLSTYLEmanager andEXPLODEsupport
Paper Space & Layouts
- Multi-tab layout system with model space and unlimited paper space tabs
- Viewport projection: Model content correctly projected into paper-space viewport rectangles
- Camera persistence: View position and zoom saved per layout; restored on file open and tab switch
- Correct paper size: Physical paper dimensions read from embedded PlotSettings (not drawing limits)
- Inline MSPACE overlay — enter a viewport with double-click; edit model entities in place
VPORTS— preset viewport configurations (single, 2H, 2V, 4-way)LAYOUTMANAGER/LAYOUTPANEL— GUI layout managerPLOTSTYLEPANEL/STYLESMANAGER— plot style table editor (CTB/STB)PRINT— send layout to system printer
Blocks & References
INSERTwith attribute prompting (ATTREQ)ATTEDIT— edit block attribute values interactivelyREFEDIT/REFCLOSE— in-place block reference editingXREF— attach, reload, and resolve external DWG/DXF referencesDATAEXTRACTION— export entity property data to CSV
Snapping & Precision
- Object snaps: Endpoint, Midpoint, Center, Node, Quadrant, Intersection, Perpendicular, Tangent, Nearest, Insertion, and more
- Ellipse arc endpoints, LWPolyline arc midpoints, Hatch boundary points
- Object Snap Tracking (
OTRACK/F11) - Polar Tracking with configurable angle increment
- Dynamic Input overlay (
DYNMODE/F12) - Grid snap with adaptive spacing
- Command history navigation (↑ / ↓)
Rendering
- GPU-accelerated via WebGPU (wgpu)
- 4× MSAA anti-aliasing
- Orthographic and perspective camera
- ViewCube with face/edge/corner snapping
- Wide polylines: LWPolyline and Polyline2D filled strokes
- Raster images: GPU-textured quad pipeline (
IMAGEcommand) - Wipeout: Solid fill masking
- Complex linetypes: Text and shape elements rendered in linetype patterns
- White/black entity colors adapt to background luminance
- Per-viewport background color (
BACKGROUND) - Visual style selector (Wireframe, Shaded, etc.)
- X-ray ghost pass for selected wires occluded by geometry
UI
- Modular ribbon interface — Home, Insert, Annotate, View, Manage, Layout
- Command line with autocomplete and history
- Layer Manager with per-viewport freeze columns
- Properties panel
COLORSCHEME— runtime theme switchingSHORTCUTS— keyboard shortcuts panelSPLINEDIT— close, open, reverse spline control points- UCS icon with 3D foreshortening and axis labels
Installation
Linux (AppImage)
Download OpenCADStudio-*-linux-x86_64.AppImage from the latest release, then:
chmod +x OpenCADStudio-*-linux-x86_64.AppImage
./OpenCADStudio-*-linux-x86_64.AppImage
No installation required — runs directly on any modern Linux distribution.
Windows
Download OpenCADStudio-*-windows-x86_64.exe from the latest release and run it directly. Windows SmartScreen may show "Windows protected your PC" because the binary is not yet code-signed — click More info → Run anyway.
macOS (Apple Silicon)
Apple Silicon (M-series) only; Intel macOS isn't built. The app is ad-hoc signed but not Apple-notarised (notarisation requires a paid Apple Developer ID), so macOS Gatekeeper guards the first launch. Pick whichever path is easiest:
Option A — Homebrew (recommended):
brew install --cask --no-quarantine \
https://raw.githubusercontent.com/HakanSeven12/OpenCADStudio/main/packaging/homebrew/open-cad-studio.rb
--no-quarantine lets Gatekeeper skip the unsigned-app prompt. See packaging/homebrew/ for publishing this as a brew tap.
Option B — manual .dmg:
Download OpenCADStudio-*-macos-arm64.dmg from the latest release, open it, and drag OpenCADStudio.app to /Applications. If the first launch is blocked, clear the quarantine flag once:
xattr -dr com.apple.quarantine /Applications/OpenCADStudio.app
On older macOS you can instead right-click OpenCADStudio.app → Open and confirm; on macOS Ventura and later, approve it via System Settings → Privacy & Security → Open Anyway.
Build from Source
Requirements: Rust 1.75+
git clone https://github.com/HakanSeven12/OpenCADStudio.git
cd OpenCADStudio
cargo build --release --bin OpenCADStudio
./target/release/OpenCADStudio
Star History
License
GPL-3.0-only — see LICENSE