We have plans for a kind of "layers" feature where you can save selected items for easy reselection later, as well as disable their selection, etc. For now, at a high level we have the Options
group on the main toolbar:
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Here you can disable selection of bones, images, and "others" (paths, bounding boxes, etc) in the viewport. Note that even when you cannot select these items in the viewport, you can still select them in the tree and that will cause them to be selected in the viewport so you can manipulate them. This means you don't usually need to toggle selection on/off for making a rare selection.
If you need more fine control, most attachments have a Select
checkbox:
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When unchecked, you won't be able to select that attachment in the viewport. Like with the main toolbar setting, you can still manipulate it by selecting it in the tree.
Something else you can do with a complex rig is to hide slots and/or bones. This can be useful to get seldom used items out of your way. In some cases it's not very useful to have them visible ever. Eg, when having bones follow a path so the bones deform a weighted mesh, usually you can hide the bones since you don't usually need to manipulate them.
Note that hiding bones or slots doesn't affect exported animation data, it is purely an editor feature to reduce clutter. Also note that hiding a bone also hides its rows in the dopesheet. This helps reduce clutter from the dopesheet, but can be confusing when you can't find the dopesheet rows!
Press H
to hide the selected items. Right click a bone's visibility dot to hide that bone and all child slots and bones. ctrl+H
(cmd+H
on Mac) will show all hidden bones and slots.