Surfaces
The Surfaces tab builds surface bodies (zero-thickness faces), listed under Surface Bodies in the tree. Cuts and Combine only act on solid bodies; Knit, Thicken or Convert to Solid turn surfaces into solids.
Making surfaces
| Feature | What it does |
|---|---|
| Extruded Surface | Sweeps the sketch's curves in a straight line; open chains are fine |
| Revolved Surface | Revolves the sketch's curves about an axis |
| Planar Surface | Fills a closed sketch (holes allowed) |
| Lofted Surface | A surface through two or more profiles (sketches or 3D sketches), open or closed, optionally ruled (straight between profiles). Open profiles drawn in opposite directions are lined up automatically. |
| Swept Surface | An open or closed sketch profile, or a circle, swept along a sketch, 3D sketch or helix |
| Filled Surface | A smooth patch over a hole bounded by edges of a surface or a solid, touching or optionally tangent to the faces round it. It can be knit into the surface and close a solid. A flat loop gives a flat patch. |
| Boundary Surface | A surface through curves in two directions. The first and last curve of each direction bound it and must meet at their ends; the curves between shape it. |
| Ruled Surface | Straight-sided surfaces standing on edges, either normal to the surface or along a direction tapered by an angle, on one or both sides (for example mould parting surfaces) |
| Offset Surface | Offsets faces of any body |
| Copy Surface | Copies faces of any body as surface bodies, leaving the body unchanged. Join copies that touch into one surface body is on by default. |
Changing surfaces
| Feature | What it does |
|---|---|
| Trim Surface | Cuts surfaces with a plane, a surface body or a sketch's curves (square to the sketch). Click the pieces to keep, or to remove. Mutual trims the tool surface too. |
| Extend Surface | Carries open edges straight on by a distance, following the surface's slope at the edge, and knits the extension on |
| Untrim Surface | Fills a surface's holes, or gives it back its natural extent (holes and outline). Pick faces to untrim only those. |
| Knit Surface | Sews surfaces together within a gap tolerance. When they enclose a volume, Try to form a solid turns them into a solid. |
| Thicken | Gives a surface a wall thickness (one side or both) and makes it a solid |
| Delete Face | Takes faces out of a solid or surface. Either leave the hole (the body becomes a surface body) or patch each hole smoothly, optionally tangent, so the solid stays solid. Good for removing fillets and bad faces from imported parts. |
| Replace Face | Moves flat faces of a solid onto a surface body, so the body grows or shrinks to meet it (for example a curved top). The surface must reach past the faces all round. |
| Flatten Surface | Unrolls faces of a surface or solid flat beside the model as a surface body (see below) |
| Split (with a surface) | Splits solid bodies with a surface body |
| Move/Copy Surfaces | As Move/Copy Bodies, for surfaces |
| Delete Surface | Removes a surface body |
Curves and split lines
| Feature | What it does |
|---|---|
| Split Line | Splits faces along a sketch's projection, or where a plane or surface crosses them. The body stays one body with its faces split, for example for a parting line, a draft or a colour. |
| Projected Curve | Projects a sketch along its normal onto faces, as a 3D curve |
| Composite Curve | Joins model edges end to end into one curve |
Projected and composite curves can be used as sweep paths, lofted surface profiles, curve-driven pattern paths and boundary surface curves.
Flatten Surface
Click the faces to unroll. Faces that unroll (cylinders, cones, bent sheets) come out exact. A doubly curved face (for example a dome) can't lie flat without stretching: it is spread out keeping its edge lengths as well as possible, and the note gives the size, the area change and how much the edge lengths changed. Relaxing passes sets how hard it tries. A closed tube needs a seam (Split Line) to open out.
Meshes and closing surfaces
- Convert to Solid (also right-click a surface body): surface bodies that together enclose a volume, or a mesh, are joined (edges closer than the gap tolerance meet) and made into one solid. When they leave gaps it says how many open edges and holes there are.
- Repair Mesh: closes the holes of a surface body or a mesh with missing pieces (flat holes with a flat face, curved holes with a filling surface, holes in a mesh with triangles), turns triangles that face the wrong way round, and makes a solid. Option: the largest hole to close.
Surface quality can be checked with Zebra Stripes, Curvature and Draft Analysis (Evaluate and Tools chapter).