Interactive REPL

The vcad repl command drops you into an interactive session where you build geometry one command at a time. Each command either creates new shapes, modifies existing ones, or queries the current state. The REPL maintains a document in memory, so every command builds on top of what came before.

vcad repl

vcad> _

You can also load an existing file as your starting point:

vcad repl bracket.vcad

Creating Primitives

Type a primitive name followed by its parameters to add geometry to the scene. Dimensions are in millimeters, and everything follows the Z-up convention.

vcad> cube 60 40 5
Added Cube (60 x 40 x 5)

vcad> cylinder 8 20
Added Cylinder (r=8, h=20)

A cube 60 40 5 creates a box with its corner at the origin extending 60 mm in X, 40 mm in Y, and 5 mm in Z. A cylinder 8 20 creates a cylinder with radius 8 and height 20, centered on the Z axis. The other primitives work the same way: sphere <radius> and cone <bottom_radius> <top_radius> <height>.

Each primitive gets an auto-generated name (Cube, Cylinder, Sphere, and so on). When you add a second cube, it becomes Cube (1). You can rename parts with the rename command:

vcad> rename Cylinder "Bolt Hole"
Renamed 'Cylinder' to 'Bolt Hole'

Transforms

Transforms operate on the most recently created or selected shape. Use select <name> to switch which shape receives transforms.

vcad> select "Bolt Hole"
Selected: Bolt Hole

vcad> translate 30 20 -5
Translated 'Bolt Hole' by (30, 20, -5)

The full set of transform commands: translate <x> <y> <z> moves the shape, rotate <rx> <ry> <rz> rotates it by the given angles in degrees, scale <factor> applies uniform scaling, and mirror <x> <y> <z> mirrors across a plane defined by the given normal vector.

You can chain transforms naturally. Each one applies on top of the previous state:

vcad> cube 20 20 40
Added Cube (20 x 20 x 40)

vcad> rotate 0 0 45
Rotated 'Cube (1)' by (0, 0, 45)

vcad> translate 50 0 0
Translated 'Cube (1)' by (50, 0, 0)

Boolean Operations

Booleans combine two named shapes into one. The syntax is union <a> <b>, difference <a> <b>, or intersection <a> <b>. For difference, the first argument is the body and the second is the tool that gets subtracted.

vcad> difference Cube "Bolt Hole"
Boolean difference: Cube - Bolt Hole -> Difference Result

The two input shapes are replaced by a single result node. You can name the result immediately by appending a name:

vcad> difference Cube "Bolt Hole" as "Plate with Hole"
Boolean difference: Cube - Bolt Hole -> Plate with Hole

Inspecting Geometry

At any point you can query the current document. The info command prints the full document structure. For specific measurements, use volume, bbox, or area:

vcad> volume "Plate with Hole"
Volume: 11,850.35 mm^3

vcad> bbox "Plate with Hole"
Bounding box: (0, 0, 0) to (60, 40, 5)

vcad> area "Plate with Hole"
Surface area: 5,801.06 mm^2

The list command shows all shapes currently in the scene:

vcad> list
1: Plate with Hole (Difference)

Building a Plate with Four Holes

Here is a complete session that builds a rectangular plate with a hole near each corner. This is the kind of iterative workflow the REPL is designed for.

vcad> cube 80 50 5
Added Cube (80 x 50 x 5)

vcad> rename Cube Plate
Renamed 'Cube' to 'Plate'

vcad> cylinder 4 15
Added Cylinder (r=4, h=15)

vcad> translate 10 10 -5
Translated 'Cylinder' by (10, 10, -5)

vcad> difference Plate Cylinder as "Plate 1 Hole"
Boolean difference: Plate - Cylinder -> Plate 1 Hole

vcad> cylinder 4 15
Added Cylinder (r=4, h=15)

vcad> translate 70 10 -5
Translated 'Cylinder' by (70, 10, -5)

vcad> difference "Plate 1 Hole" Cylinder as "Plate 2 Holes"
Boolean difference: Plate 1 Hole - Cylinder -> Plate 2 Holes

vcad> cylinder 4 15
Added Cylinder (r=4, h=15)

vcad> translate 10 40 -5
Translated 'Cylinder' by (10, 40, -5)

vcad> difference "Plate 2 Holes" Cylinder as "Plate 3 Holes"
Boolean difference: Plate 2 Holes - Cylinder -> Plate 3 Holes

vcad> cylinder 4 15
Added Cylinder (r=4, h=15)

vcad> translate 70 40 -5
Translated 'Cylinder' by (70, 40, -5)

vcad> difference "Plate 3 Holes" Cylinder as "Mounting Plate"
Boolean difference: Plate 3 Holes - Cylinder -> Mounting Plate

vcad> volume "Mounting Plate"
Volume: 19,194.69 mm^3

Each cylinder is created, positioned, and subtracted in sequence. The intermediate names make it easy to follow the progression, though in practice you would name only the final result and let the intermediates take default names.

Exporting and Saving

When you are satisfied with the result, export to a mesh format or save the document:

vcad> export result.stl
Exported STL to result.stl

vcad> export result.step
Exported STEP to result.step

vcad> save plate.vcad
Saved document to plate.vcad

The export command infers the format from the file extension, just like the CLI vcad export subcommand. The save command writes a .vcad file that preserves the full parametric history, so you can reload it later and continue editing.

Undo and Redo

Made a mistake? The undo command reverts the last operation, and redo brings it back:

vcad> undo
Undone: Boolean difference

vcad> redo
Redone: Boolean difference

You can undo multiple steps by running undo repeatedly. The entire history is preserved until you exit the session.

Exiting

Type exit or quit to leave the REPL. If you have unsaved changes, you will be prompted to save or discard them. You can also press Ctrl+D to exit immediately.

vcad> exit
Unsaved changes. Save before exiting? [y/N] y
Save to: plate.vcad
Saved document to plate.vcad

The REPL is a good environment for experimentation -- you can try operations, inspect the results, and undo anything that does not work. For keyboard-driven editing with a visual preview, see the TUI tutorial. For automating repetitive tasks, see Scripting & Pipelines.