Triangulate polyline
The tool Triangulate polyline fills a selected closed polyline with triangles, generating a surface.
Click Design 3D.
Click Triangulate polyline.

The function opens a new panel on the right.

Surface: the surface subproject where surface is created. Can be a new surface or an existing surface.
Layer: the layer for the new surface.
Color: the color of the new surface.
Select the closed polyline and confirm the selection.

The surface is created.
