The Daz Importer has a mechanism that lets users add functionality, i.e. an add-on system. Blender of course
already has an add-on system, and you could write Blender add-ons that
invoke the import-daz module, but that approach has some drawbacks. In
particular, such "horizontal" calling will break if the name of the
import-daz module is changed, e.g. to
diffeomorphic-import-daz-bb15d1ca5708. A cleaner solution would be that
add-ons for the Daz importer could be handled by the importer itself.
A Daz importer add-on is a python file that you
put in the addons directory (under the import-daz directory, which
itself is located under Blender's addon directory). It must contain the
same information as a Blender add-on: a bl_info dict, and a register and
an unregister function. Packages are supported; in that case the file
__init__.py, must contain the bl_info dict and the register and
unregister functions.
The
file __init__.py in the addons folder should not be touched. It is an
empty file which is necessary to make the addons directory into a Python
package.
Information about the add-ons is found in the
new Add-Ons menu. When no add-ons are loaded, it only contains the
buttons Refresh and Save Settings.
When
we press Refresh a list of add-ons appear below the buttons. All
add-ons are loaded into memory, but they are not yet registered.
The interface is very similar to Blender's native add-on interface, cf
https://docs.blender.org/manual/en/latest/preferences/addons.html.
Each add-on has an arrow button, an enable checkbox, and the name of
the add-on. The arrow button displays more information about the add-on,
which is extracted from the bl_info dict.
When the checkbox is enabled, the add-on's register function is executed.
The
Save Settings button saves a list of enabled add-ons. The next time
Blender is started (or when the F8 key is pressed), these add-ons are
loaded and enabled.
