Feature Downgrade

Feature (document object)

Downgrade feature extracts all subelements of certain type from a shape. The extracted elements are packed into a compound.

Lattice Downgrade is different to Draft Downgrade in a few things:

• Lattice Downgrade is parametric, while Draft Downgrade is not parametric.
• Lattice Downgrade outputs all subelements packed into a compound, while Draft Downgrade explodes the shape into many document object. Lattice Downgrade does that to be parametric; if subelements are required as separate document objects - use Explode Compound tool.
• For Lattice Downgrade, you directly choose the type of elements to return, without needing to figure out the number of times to downgrade. Effectively, it can make a number of Draft Downgrade steps in a row.
• Lattice Downgrade can do a few other things, most notable one is extracting open wires of shells. Or it can extract only solids from a heterogeneous compound.

Properties

Base

Link to shape to be downgraded.

Mode

Sets, what type of elements to extract.

• bypass: output the shape intact.
• Leaves: extracts all leaves of compounding tree. Effectively, removes compound nesting.
• CompSolids: extracts all CompSolids from a shape. CompSolids compares to a solid like a wire compares to edge: CompSolid is a set of solids connected by sharing faces. CompSolids are barely supported by FreeCAD. They can be made by revolving or extruding shells.
• Solids: extracts all solids (can be used to break apart CompSolids).
• Shells: extracts all shells (sets of faces connected by sharing edges).
• OpenWires: for all shells, extracts edges that are not shared. This can be used to find holes in shells, and then patch them.
• Faces: extracts all faces.
• Wires: extracts all wires (sets of edges connected by sharing vertices).
• Edges: extracts all edges.
• Vertices: extracts all vertices. The elements extracted are put into a compound.

GUI Command (toolbar button)

There are 9 "Downgrade to ***" commands that create Downgrade feature. Each command corresponds to 'Mode' property preset (all values are covered except bypass).

Select an object to downgrade, and invoke the command. Often, the action of Downgrade is not apparent. Probe the original and resulting objects with Lattice Inspect tool to see the difference.

In case an action similar to Draft Downgrade is wanted, consider Exploding the output of Downgrade (or even Exploding the original directly).