How do I add a center vein to a leaf, or creases and ridges to a 3D shape?

Pick the method by the kind of line

A raised ridge is best built into the shape when you sweep it. A recessed crease is best taken away afterward. Fine veins can also be cut by the tool instead of modeled.

Method 1: a ridge built into a Two Rail Sweep

1. Use the two sides of the leaf (or two smooth lines just outside it) as the drive rails. Select both and click Use Selection.
2. Draw an open cross section vector with a node at the peak where the ridge should be.
3. If you use more than one cross section, give them all the same number of spans and nodes, then check Sweep between spans. The shape then flows from each node to the matching node on the next cross section, so the crease runs cleanly along the length.
4. Check Scale cross sections with width so the shape gets lower where the rails come together, as a leaf does at its tip.
5. Apply, then crop the result back to the true leaf outline with Clear Component Outside Selected Vectors. The official documentation shows exactly this leaf example.

Method 2: a recessed crease with Subtract

1. Draw a thin closed vector where the vein or crease should be.
2. Open Create Shape, choose a profile, and set the combine mode to Subtract.
3. Keep the crease vector fully inside the shape it cuts into. The official guide notes that Subtract works best that way and shows a lioness whose muscle creases were made with this method.

Method 3: sculpt it

Select the component, open Sculpting and use Remove with a small Diameter and low Strength. Click Keep each time you are happy so a later Discard only loses recent strokes.

Method 4: let the bit make the veins

The official documentation mentions fluted veins on a leaf as detail created by the tool shape. Draw the veins as open vectors and cut them with a toolpath over the finished carving (see the entry on the Fluting Toolpath for the ramp options).

Pro tips

• If the sweep twists, right-click a rail and choose Reverse Rail so both rails run the same direction.
• Sculpting several components at once forces a bake, so keep a copy first.
• See the entry on the oversize then cookie cut technique for more on cropping swept shapes.