Creating the Active Geometry from a Sketch
You can create the active geometry from a sketch.
Open the product (not a 3D part) containing the model and activate the representation containing the cavities.
Select the shape that contains the geometry of the electrode cavity.
It can be a 2D or a 3D shape.
An axis system is created from the selected shape, and proposed as the
Electrode Direction
.
Select
Sketch Active Geometry
in the
context toolbar
and a plane.
Draw a sketch and exit the sketcher.
The top face of the shape is split by the projection of the sketch. The resulting split is highlighted.
Select
Extract Cavity Geometry
in the
context toolbar
to extract the active geometry.
You can now add a reinforcement.
in the 
in the