Blender 2.8 UI panel location for a complex add-on


I’m thinking about creating an Blender add-on, which needs a pretty large and likely complex panel, with many settings and options. The add-on will not be likely specific to any one mode (e.g. edit or object mode). I seek advice about what would be a good place for this panel. According to the location is free, but at least two alternatives exist: either a separate Side Bar Tab like the 3D Print Toolbox, or a tab in the Properties Panel:

Any thoughts? Is there any difference (besides location in UI) between using Side Bar Tab or Properties Panel?


That document was mainly written to make addon developers reconsider if everything necessarily has to be added as a panel to the sidebar.

Afaik you cannot currently add a custom tab inside Properties. But you can add a panel there, inside the tabs that already exist. If your addon is connected to the Properties data, like material, mesh, objects etc, then it makes sense to go there.

If it’s just a command, add it to the menus.

If it’s an active tool, there will be an update to the tools API shortly to make it easier to add toolbar tools.

Some addons make sense as a separate editor, like if you want to make an asset browser for eg.

If it doesn’t fit any of the above you can still add a panel to the Sidebar.

Also consider if it even makes sense in the 3d view, or if it should be in another editor, depending on what kind of data it interacts with.

I’m also needing a good solution for this. Is there any documentation about adding a new Editor from python; though I’m not really sure what Editors can offer? Or is that not really possible.

I’m trying to address something of mine which is tied to a particular Collection, so it couldn’t really fit as a Panel for the existing properties:

Apparently the custom editors capability was not finishes yet, sorry.