Free 3D sculpting and organic modeling online

The FORM tab is for shapes you would not describe with dimensions: a handle that fits a hand, a vase with a soft outline, a figurine, an enclosure without hard edges. You start from a simple shape wrapped in a sparse grid of points and move those points, edges and faces, while the program keeps the surface between them smooth. The result is an ordinary solid you can fillet, combine with other parts and save as STEP or STL.

That grid is called the cage. Think of a wire frame under stretched fabric: every vertex is a handle the surface follows gently.

Getting started

1. Pick a starting shape: Box, Plane, Cylinder, Sphere, Torus or Quadball. A dialog asks for the size and the number of faces. Start with few: more faces means more handles, but also more points to manage.
2. Switch selection to vertices, edges or faces (keys 1, 2 and 3), pick them in the viewport and drag them with the handle.
3. Add material where it is missing: Extrude Faces pushes out a new section, Insert Edge adds a ring of edges where you need more detail, and Face adds new faces as you click their corners (singly, in a strip or as a grid).
4. Bridge replaces two selected faces with a tube of new faces, so both need the same number of corners. The Delete key removes selected faces.
5. Click Finish Form or press Enter when you are done. Ctrl+Z undoes edits as you go.

The cylinder starts as an open sleeve. Fill Hole closes every opening in the cage at once, both ends of a cylinder. To keep one end open, select the face that closed it and delete it.

Tools that save time

• Symmetry: a change on one side is repeated on the other. Circular Symmetry does the same across several sectors around an axis, for example a vase with six identical ribs.
• Crease keeps a sharp edge inside a smooth form, and Uncrease smooths it again.
• Smooth, Flatten, Straighten and Average even out selected points after dragging by hand.
• Pull and Match snap form points onto an existing body or its edges, so the form fits the part next to it.
• Thicken turns an open surface into a form with a wall thickness.
• Freeze locks points that must stay where they are.
• Canvas, in the same tab, puts a photo or drawing on a plane to sculpt against.

What you get at the end

Finishing the form turns the smooth shape into an exact solid, described by curved surfaces rather than triangles. It takes fillets, can be joined with or cut from other bodies, and exports to STEP (see file formats).

If that fails, for example with a very dense or tangled cage, Foremka offers a mesh body instead. It is fast and fine for 3D printing, but solid operations do not apply to it. Repair Body cleans up the cage, and Edit Form or Edit on the timeline takes you back into a finished form.

Limitations

• Shell works on a form body, with an open face too, but takes longer than on a regular solid, usually half a minute or more, because a form is made of hundreds of smoothly joined patches. A vessel with even walls is quicker inside the form: leave the cage open and use Thicken.
• An inserted edge loop runs all the way around the form, so adding detail in one place also adds edges where you do not need them.
• The starting shape is always placed at the origin.
• The server computes the exact solid; the browser computes a mesh body.