Part Modeling > Part Modeling > Base Features > Extrude > Basics of the Extrude Feature > About the Automatic Add or Remove Material Option
About the Automatic Add or Remove Material Option
The auto_add_remove configuration option automatically detects whether to add or remove material during feature creation. This option applies to Extrude and Revolve features, and the default is set to yes.
When you set the auto_add_remove configuration option to no, you manually remove material by clicking Remove Material on the feature tab. If you do not click this button, material is added to the model.
Conditions for Using auto_add_remove
The auto_add_remove configuration option is set to yes.
The feature is currently being created. The option is not available when you edit an existing feature.
The Surface button is selected.
The Remove Material button was not clicked. When you click this button, you override the automatic setting.
The value of the main entity of the feature is changed. This varies for each feature and is described below.
An Extrude or Revolve feature is being created.
When the Variable depth option is selected, the Extrude feature is to one side. The option does not apply to two sides.
How auto_add_remove Works
When the auto_add_remove configuration option is set to yes, an analysis is performed after you open a tool, sketch or select a section, and change a value for a main entity. The analysis detects whether or not the feature that you are currently creating intersects with the model geometry. Based on this analysis, the feature is automatically set to either add or remove material.
If a feature being created lies entirely inside a solid model, the default choice is to remove material. If a feature being created lies partially or entirely outside a solid model, the default choice is to add material.
When the default option changes the setting of the Remove Material button, a message that points to the button appears to inform you that a change has been made.
Main Entities for Specific Features
There is one main entity for each feature. When you change the value for this entity during feature creation, an analysis is performed. You can change the value by dragging the entity handle in the graphics window, by typing a value in the graphics window, or by typing a value on the feature tab.
For an Extrude feature, set a depth value.
For a Revolve feature, set an angle value.