Work with bodies: primitives, combine, move and mirror

Your bodies in the browser

Every step set to New makes a body: an extrude, a revolve or a primitive. Fillet numbers them Body 1, Body 2 and so on. Tap Browser at the left end of the tool strip to see them.

The browser lists Body 1 with a teal icon, Body 2 greyed out with a crossed-out eye, and Body 3 lifted with its menu open: Color, with a tick on Slate, then Red, Orange, Yellow, Green, Teal, Blue, Purple, Pink, Brown, White and Black, each with its own dot. In the view, a teal plate holds a grey ball. — Body 1 is teal, Body 2 is hidden, and Body 3's colours are open.

Tap a row to select the body. Tap it again to let go.
Tap the eye to hide or show the body. The Print check and exports leave hidden bodies out.
Touch and hold a row to give the body a colour.

Colour a body

Colours tell bodies apart on screen, so you can see which one is which when they overlap.

Touch and hold the body’s row in the browser.
Tap a colour. Slate is the default grey.

Control-click the body’s row in the browser.
Choose a colour. Slate is the default grey.

The row’s icon and the body in the view take the colour. Colours stay on screen and don’t go into exported files.

Add a primitive

A primitive is a ready-made solid. You don’t need a sketch for it.

Tap Primitive in the tool strip.
Choose Box, Cylinder, Sphere, Cone or Torus.
Type its sizes and its Position on the plane.
Tap Done.

A grey cylinder standing on the cream bed. — A new cylinder stands on the bed at the origin. Type a size and it changes as you go.

The Cylinder 1 inspector: Shape Cylinder, Operation New, Diameter 20 mm, Height 20 mm, Plane XY (bed), Position X 0 mm and Y 0 mm. — A new cylinder stands on the bed at the origin. Type a size and it changes as you go.

Shape	Sizes	Where it sits
Box	Width, Depth, Height	Stands on the plane
Cylinder	Diameter, Height	Stands on the plane
Cone	Bottom Diameter, Top Diameter, Height	Stands on the plane. A top of 0 makes a point.
Sphere	Diameter	Centred on the plane
Torus	Major Diameter, Minor Diameter	Centred on the plane

Plane is XY (bed), XZ (front) or YZ (side). Operation works as it does for an extrude: Cut with a cylinder makes a quick round hole in every body it passes through.

Combine bodies

Combine cuts one body with another, or joins them. The target is the body that stays. The tool is the body that cuts or joins it.

Tap Combine.
Under Target, choose the body to keep.
In the view, tap the tool body. Tap it again to take it out.
Choose Join, Cut or Intersect, then tap Done.

Before: a grey plate with a blue cylinder standing through it. — Target Body 1 (the plate), tool Body 2 (the cylinder), Operation Cut. The cylinder is used up and leaves its hole.

After: the plate alone, with a round hole where the cylinder stood. — Target Body 1 (the plate), tool Body 2 (the cylinder), Operation Cut. The cylinder is used up and leaves its hole.

Operation	Result
Join	The target and the tools become one body.
Cut	The tools are cut out of the target.
Intersect	Only the parts where they overlap are kept.

To keep the tool as well, for a pin that also cuts its own hole, turn on Keep tool bodies.

Select bodies before you tap Combine, and the first one becomes the target and the rest become tools.

Move and rotate bodies

Move places bodies by exact distances and angles. You type every value.

Select the bodies to move. With nothing selected, Move takes every body.
Tap Move, or press ⇧Shift⌘CmdM.
Under Translate, type the X, Y and Z distances in millimetres.
Under Rotate, pick an Axis and type an Angle, then tap Done.

Top view: a blue box sits on the Y axis, 40 mm above the origin. A dashed outline on the X axis shows where it started, and an orange arc around the origin joins the two. — Rotate turns about the origin, not about the body. Angle 90° about Z swings this box, seen from above, from the X axis round to the Y axis.

The Move 1 inspector: 1 body picked, Translate X, Y and Z all 0 mm, Rotate Axis Z, Angle 90 degrees. — Rotate turns about the origin, not about the body. Angle 90° about Z swings this box, seen from above, from the X axis round to the Y axis.

Rotation comes before the move. To turn a body in place, rotate it while it sits on the origin, and move it in a second Move. Tap a body in the view to add it or take it out while Move is open.

Mirror bodies

Mirror copies bodies to the other side of a plane through the origin. Draw one half beside the origin, and Mirror makes the other.

Select the bodies to mirror. With nothing selected, Mirror takes the newest body.
Tap Mirror.
Choose the Plane. YZ (side), the default, mirrors left to right.
Tap Done.

Before: one L-shaped half, with its inner end on the origin. — One L-shaped half against the origin, mirrored across YZ (side), makes a cradle.

After: the half and its mirror image joined into one U-shaped cradle. — One L-shaped half against the origin, mirrored across YZ (side), makes a cradle.

Merge with original is on, so the copy joins the half and you get one body. Turn it off to get the copy as a body of its own.

Bodies from elsewhere

A STEP file you import arrives as a body named after the file. Fillet it, cut it, combine, move and mirror it like a body you drew. An AI agent can also add Scale and Loft steps. Tap one in the timeline to change its values.

Import a STEP fileBring in a part from another CAD app as a body.Design with AI agentsLet Claude Code or another MCP client build while you watch.

Questions

Why is Combine greyed out?: It needs two bodies. Add another one, a primitive for example, and try again.
Where did my tool body go?: Combine uses it up. Tap the Combine step in the timeline and turn on Keep tool bodies.
Why does my export miss a part?: The part is probably hidden. Tap its eye in the browser to show it.
Can I drag a body into place?: No. Move takes typed values, so every position is exact and you can change it later in the timeline. Fields take parameters too, like wall * 2.