Constrain features by mask

[D.Angst]

Hello,
I am trying to merge to chuncks of images, corresponding to the top and the bottum part of the same object, to try to mak one 3D model of this object. When I am trying to 3Align Chunks", I don't have the box "Contrain features by mask"... Why? What can I do? Is this option only in the pro edition? Is there another way to align my 2 chunks?
Many thanks for your help.

[Alexey Pasumansky]

Hello D.Angst,

The equivalent of the "Constrain features by mask" option in the latest release is "Apply Masks to -> Key Points" option.