Archive notice: This article was originally published on August 21, 2019. Links and embedded videos are preserved as part of the historical record.
Anyone who has wanted custom controls for navigating Maya’s viewport should take a look at Screenspace. Screenspace is a free plug-in by Animal Logic Software Engineer Eddie Hoyle. With the tool, you can add your own shapes, for example for transforming objects, and integrate them into the viewport.
The Pickables
The tool makes it possible to assign simple geometric shapes—the “Pickables”—in any colors to different parameters, then position them anywhere. These Pickables can then be used by clicking or dragging.

Interface for rigs
As can be seen in this example, it can also be used to create facial Pickables for character rigs or hard-surface rigs.

Availability
The plug-in is available under the free Apache 2.0 license for Windows, macOS and Linux here on Github . You can find instructions here.