# Replace Surface

Change the shape of the solid/surface by replacing some of the faces in the solid/surface with a new surface.

Instructions for use

Click to enter the replacement face command, whose interface is shown below.

The meanings of each control are as follows:

Face to be replaced: Select a face on an entity or surface. Multiple choices are supported. The selected faces should be connected and belong to the same entity/surface. When selecting, each face in the surface can be selected separately.
Target surface: Select a single surface. When selected, the surface composed of multiple surfaces is regarded as a surface.
When replacing, delete the surface to be replaced, extend and cut the adjacent surface and the target surface of the surface to be replaced, change the shape of the entity/surface, and generate the features of the replacement surface.

Regular adjacent and target surfaces (such as cylindrical surfaces) are extended in a regular way, and irregular surfaces (such as imported irregular surfaces) are extended in the tangential direction
If the adjacent and target surfaces cannot be intersected after being extended, no replacement is made and the error "the selected surface cannot be replaced" is reported.
After replacement, the entity is still the entity, the same as the surface.

Select the surface to be replaced and the target surface in different cases, and the result is as follows

The selected face situation	result
The target plane is outside the entity
The target plane is inside the entity
The target plane is outside the entity and in the opposite direction of the plane to be replaced	Cannot be replaced with an error
Face to replace Select multiple faces
Extend the adjacent face of the face to be replaced without intersecting the target face	Cannot be replaced and an error is reported
The surface to be replaced has a groove, and the side wall of the groove has a drawing Angle	The side wall of the groove extends along the drawing Angle (in the picture on the right, the extended groove opening becomes larger)
The face to be replaced has grooves, The target surface is below the bottom of the groove	Replace normally and the groove is removed along with the face to be replaced