The first thing you will notice when you fire up Rapid Rig: Modular 3 in Maya is the change in the User Interface. RRM3 (left) has been decluttered and broken up into more tabs to reduce information overload.
To create new proxy modules, users no longer need to scroll through the list of module types like in pre V3 (right). Now, simply click the button of the module type you want, and the properties for that module will be there. Woo!
Editing proxy modules has also been improved. Again, gone are the days of scrolling through and having to load the correct module. You can choose from the dropdown of existing modules, or select the module you want. So nice!
Once you select the module you want to edit, it will load the existing properties on that module. PreV3 did not have this functionality.
There are lots more to talk about with proxies, but this blog post will get too long.
Rig Generation Settings
Generating rigs has also been de-cluttered. And, all options are set in Rapid Rig: Modular 3 pre-build (left), including single hierarchy joint settings.
And new to Rapid Rig: Modular 3 is joint orientation settings and renaming to Unreal's expected naming conventions. Sweet!
Setting a rest pose where you want to align your controls to the world has been drastically simplified in Rapid Rig: Modular 3 (left). Just rotate your control somewhat in the vicinity of the world axis you want, and press "Apply Nearest World Space Rotation to Select Control" button. Gone are the days of having to specify which direction you want to orient it, which could be confusing to less experienced users.
And! You can now save and load rest poses. This is great if you have rigs that are similar, or ever need to back up the setting.
Rebuild Rig Settings
New to the rebuild settings is preserving animation data (great for not losing range of motion animation tests) and layer data, in case you like to change up the layers. Yay!
Motion Builder Name Settings
The Motion Builder tab has been beautified, and new functionality has been added. Users can rename both sides at once, rather than one part at a time. And names can also be reset back to their original names in case of a mistake. Neat!
And one last thing I will mention, is you can now rebuild a rig without an existing proxy rig. If you ever lose your proxy rig, don't worry! That data is stored in the rig and a new proxy rig will be generated before rebuilding the rig. How cool is that!