A direct modeller, built in.

Draw on an origin plane, a flat face of a body, a datum plane, or a plane through a point you click. The sizes follow the cursor as you draw: just type, Tab to the next box and press Enter, with expressions and units if you like. Points snap to ends, midpoints, crossings and extensions, then to the grid.

• Where the sketch plane cuts a scan, the scan's outline is drawn in magenta and points snap to it, so you draw straight from the part.

Lines, construction lines and tangent lines; splines; rectangles by two or three points; circles by centre or three points; ellipses; polygons of 3 to 64 sides sized across the flats; semicircles; and sweep, three-point and tangent arcs. Every size can be typed, and a line or an arc can be drawn out equally both ways from its middle.

• Construction geometry is dashed, snapped to, and never made into faces.
• Set a mirror line, and everything drawn after it is mirrored and kept symmetric.

Round or chamfer a corner, bring two curves to a corner, split a curve, offset a copy, bow a line through a point, resize a selection to a typed width or height, or trim away the stretch between crossings. Draw a contour straight onto a scan, or fit editable lines and arcs to the section the sketch plane cuts through it.

Show every size on the sketch at once, double-click one and type a new figure, and the sketch changes to hold it. The sketch history says how many degrees of freedom are left, fully constrained when none are, and warns when rules disagree. Measure reads diameters, arc lengths, angles and the distances between curves.

Click a face, double-click an edge for its loop, or click again for the whole body. Power Selection lists every hole, round or chamfer of the same size, the faces on the same axis or of the same area, and the pattern a feature belongs to, so one click takes them all. Recognise patterns of holes and bosses, keep faces coaxial or at a set offset, and an edit then carries to every partner in the same step.

Press a face or a closed profile and drag it along its normal, or type the distance. A profile becomes a solid, a face grows or cuts the solid, and a hole or a boss changes size. The same tool revolves, sweeps along a path, pivots a face about an edge, and moves faces up to another face or to leave an exact gap.

• Up To moves every selected face exactly onto the face, plane, edge or point you pick, in one step; stopped at a tilted face, it takes that face's angle.
• Add material, cut it, or make a separate body; pull both ways at once; snap to heights already in the model.

Round or bevel an edge by dragging it or typing the size; double-click for the whole loop. Rounds can be circular, conic or curvature-continuous; tapered from one end to the other; held to a line on the face; or given different radii and setbacks at a corner, with a patch to fill it.

• Variable radius: set the radius along a whole smooth run of edges on a graph, straight or smooth between points, previewed as you drag.
• Chamfers by two distances or a distance and an angle, or copied from a chamfer already on the part.
• Press a round to change its size, or delete it to take it off and rebuild the faces beneath.

Move or turn a body, a face, or a whole feature, a boss, hole, pocket or slot, with its handle or by exact values: along an axis, round a ring, up to something you pick, or along a path. Leave copies behind as you go to make a pattern.

Merge joins solids into one body. Intersect cuts bodies with others into separate pieces and lets you click away the ones you don't want: that is how you subtract, and how you keep only an overlap. Split cuts a body with a face or a plane, or divides a face along sketch shapes drawn on it or projected onto a curved face.

Fill takes out a hole, pocket, boss or round and closes the gap by extending the faces round it. Replace Face lays faces onto a target surface, or onto a plane, cylinder or cone fitted to the faces themselves, and trims their neighbours to it. Tweak Face reshapes one face by its control points.

Lean faces by an angle so a moulded or cast part comes out of its tool. Pick the neutral plane, then the faces, then the angle; each face turns about the line where it meets the neutral plane. Flat faces tilt, bosses and holes become cones, a boss wider towards the neutral plane and a hole narrower, and the faces next to them are trimmed to meet.

Sweep carries a profile along a path of edges or sketch curves, square to the path or sliding, with a twist if you want one. Blend makes a solid through two or more profiles in order, steered by guide curves, with tangent or curvature-continuous ends, ruled, or closed into a ring.

Place datum planes (offset, at an angle about an edge, through three points, midway between two faces, tangent to a cylinder), axes and origins to model from. Thread cuts an ISO metric thread into a boss or a hole: coarse or fine to ISO 261, from M1.6 to M64, sized from the face's diameter, right or left hand, over the whole length or a set distance.

• Or sweep a section you draw round an axis, with its own pitch and number of turns, for a custom thread or a spring.

Copy a body along a line, round an axis, or along any curve: an edge, a sketch curve, a scan contour or a mesh rim, with the copies square to the world or turning with the curve. Up to 10,000 copies, previewed a hundred at a time. Mirror makes a twin across a face or a plane, and mirrors sketch curves, meshes and point clouds too.

Shell hollows a solid to a wall thickness, open through the faces you pick or closed. Offset makes a sheet at a distance from faces. From the search, Enclosure puts a box, cylinder or sphere round a body with a clearance, Midsurface makes a sheet midway between two faces, and Volume Extract makes solids from the cavities inside a body.

Make a solid or a surface bigger or smaller by one factor, so circles stay circles and exact shapes stay exact, about its centre, its base or the world origin. Pick a unit correction for a part that came in at the wrong size. Meshes and point clouds can be stretched differently along X, Y and Z (see Scale on the Mesh tab).

Measure reads a cylinder's diameter and length, a fillet's radius, a face's area, an edge's length, and the distance and angle between any two picks. Deviation colours one Design body by its distance from another body or from a scan mesh, and follows your edits while it is open.

Look inside a body through a clipping plane. The cut lines stand for the faces they cut, so extruding, moving, rounding or deleting a cut line acts on the whole face, and the drawing tools sketch on the section plane.

Everything you make is kept as a history of steps. Roll back to see the model as it was, change a step's value, even as an expression with units, and the model is rebuilt from that step. Each sketch keeps its own history as well, with steps you can reorder or switch off.

Open a supplier's STEP or IGES file as exact, editable solids, and pull, round and split its faces as if you had modelled it yourself; cylinder and cone walls other programs split in half can be rejoined as they come in. Save the model as STEP, as IGES solids or trimmed surfaces, as DXF sections or 3D edges, or as a mesh.

• Measured55 of 56 real-world STEP files in our test library opened as editable solids