This option applies to surfaces only and essentially affects the program behavior about surfaces.

• When this check box is selected, the domain of the resulting entity will have the same size as the one of the original entity.
• When not selected, the domain of the resulting entity may differ from the original (and be smaller: in fact it will be reduced to the trim boundary domain).

In the following example you can see a trimmed surface:



If you apply the GSM Bend command and check the Keep original domain box you will obtain the following result, in which the initial domain has been clearly retained on the result surface.



The following image shows what you would have obtained when untrimming the surface if the Keep original domain box had not been checked.