CAD Curve

CAD Curve brings CAD-style construction to the 3D Viewport. Pick a tool from the T-toolbar, click, type a length if you want, and confirm. Previews stay temporary until you finish, so Esc never leaves junk in the scene.

Version 1.0.1 · Blender 4.2+ · Windows, Linux, macOS

Features

• Arch, rectangle, circle, ellipse, polyline, and NURBS spline drawing

• 2D Offset, Fillet, and Chamfer on planar curves and meshes

• SketchUp-style Guide Tape with snappable dotted construction lines

• Live dimensions and typed measurements (2m, 5, width,height)

• Scene units: metric, imperial, or unitless

• Ortho lock, grid snap, and vertex / midpoint / edge / face snap

• Working planes, including Auto Surface and Surface Curvature

• Tools on the T-toolbar, Add → CAD Curve, and the N-panel

Quick start

1. Move the mouse into a 3D View.

2. Choose a CAD Curve tool from the T-toolbar.

3. Click to place points. Move the mouse to preview dimensions.

4. Type a length for an exact size (2m, 5, or width,height), then Enter.

5. Enter or the last click confirms. Esc or right-click cancels and creates nothing.

Object Mode creates an editable curve. Mesh Edit Mode appends the result into the active mesh.

After a tool finishes, press F9 for Adjust Last Operation (plane, snaps, measurements, and transform). Use Blender undo after geometry exists.

Drawing tools

Arch

• 3 Point Arch — start, end, then a point on the arc. Type a chord length, then S for sagitta or R for radius.

• Center Point Arch — center, start, end.

Rectangle

• Center Rectangle — click the center, then a corner. Type width,height (one number makes a square).

• Start/End Rectangle — opposite corners.

• Rounded Rectangle — opposite corners; press R and type a corner radius.

Circle

• Center Point Circle — click center, then size. R is radius mode, D is diameter mode.

• 3 Point Circle — three points on the circle.

• Ellipse — click center, then a corner. Type width and height.

Curve

• Polyline — click corners continuously. C closes the shape. Alt+F fills a closed outline as an n-gon face. Backspace undoes the last point when the number field is empty. Enter or right-click finishes.

• Spline — smooth NURBS spline with the same Backspace undo. Enter or right-click finishes.

Modify tools (2D only)

Offset, Fillet, and Chamfer work on planar curves and meshes. 3D solids are rejected.

Offset

AutoCAD-style parallel copy.

1. Choose Offset.

2. Click a 2D line, polyline, spline, rectangle, arc, circle, or planar mesh.

3. Move the mouse to the side you want.

4. Type a distance such as 0.2 or 2m, then Enter — or click to confirm.

Circles and arcs stay concentric. Polylines and rectangles get mitered corners. Splines stay smooth. A planar mesh face becomes a new mesh copy. Backspace lets you pick another source.

Fillet

Round one corner, or every corner, of a 2D curve or mesh.

1. Choose Fillet.

2. Click the line or corner you want on a planar polyline, rectangle, or mesh.

3. Only that corner is changed. Press A if you want every corner.

4. Type a Radius (0.2, 50mm) or move the mouse, then Enter or click.

The source object is edited in place.

Chamfer

Cut one corner, or every corner, of a 2D curve or mesh.

1. Choose Chamfer.

2. Click the line or corner you want on a planar polyline, rectangle, or mesh.

3. Only that corner is changed. Press A if you want every corner.

4. Type Distance 1 and Distance 2 (Tab or comma switches fields). One value uses the same distance on both edges.

5. Enter or click to confirm.

The source object is edited in place.

Guide (Tape)

SketchUp-style dotted construction lines. No measurement labels are drawn on the guide.

Offset from an edge

1. Choose Guide (Tape).

2. Click a mesh edge (for example the bottom of a 3 m cube).

3. Move the mouse along the offset direction.

4. Type 2m and press Enter (or click). A dotted guide sits 2 m from that edge.

Free guide — if the first click is not on an edge, the tool draws a guide between two points and asks for Length.

Guides go into the Guide_Tape collection. They do not render.

Length (Preferences or N-panel):

• Full World — spans the world; World Size is the total length (default 1000).

• Fixed Length — uses the Length value.

• Match Source — matches the source edge or measurement.

Style:

• Real Dashes — real short edges, so Blender’s magnet snap can hit the guide.

• Overlay Dots — zoom-scaled overlay; CAD Curve tools still snap to it.

Always Snap To Guides (on by default) snaps to guides without holding Ctrl/Cmd.

You can snap to endpoints, the midpoint, anywhere along the line, and intersections of two guides. For Blender’s native tools, enable magnet snap with Vertex and Edge.

N-panel → CAD Curve → Guide Layers lists every guide. Hide, delete one, or delete all.

Snapping the first drawing point to a guide also moves the drawing plane to that height, so a shape started on a 2 m guide stays at 2 m.

Shortcuts