You can project individual points and curves, and loops or a face (to project all loops on the face at once) to another feature. The projected geometry is associative to the parent geometry, unless you use the Break Link command to end the associativity. For example, a rectangular projection of a slot inherits changes to a fillet on the parent slot. You can delete a projected loop.
You can place a sketch on or offset from a part face. Like projecting a face from another part in an assembly, the Project Geometry command on the Sketch tab selects edges and loops or all loops on a face. It projects them onto a sketch plane. The Select Other command cycles through and highlights each possible selection.
When creating a part in an assembly, you can project loops from an existing part to the sketch of the new part. You can select edges, loops, or a face. The projected geometry is associative to the parent part, unless you break the link. In the browser, a Reference symbol displays beneath the sketch symbol.
Changes to the parent feature or face, such as causing the loops to overlap, automatically trims the projected loop. If the geometry is projected one curve at a time instead of a loop, the projected geometry is not trimmed.
A selected face highlights only when selection is ambiguous, and your selection is a single-curve loop such as a closed spline, ellipse, or circle. Sometimes a loop comprises multiple segments, such as a rectangular slot. The Select Other command cycles through the edges and faces of parent geometry so you can see what to project.
The highlighted loop helps you understand the origin of the projected geometry. When the parent geometry updates, the loop update is different, depending on which face the loop is from, particularly if line segments are added.