I played around with the animation brush settings and the foundation is quite good,but some things stand in the way of it being more easily useable. right now creating a custom brush is done in a seperate krita window which can make it akward to set up and reuse assets from the scene you are working on. It's never something you can do on the fly. I would suggest a few options 1)dedicated animation brush group. ->choose animation group from list of layer types. set local selection to control the brush dimensions. This would make it easier to exclude other layers from being used in the animation brush. It would only take into account the layers inside that animation group 2)mark group as animation group . ->same as previous option but instead of dedicated group in the layer types list, this would be an extra icon (next to lock and visbility icon) to mark an group as animation group. The positive side to this is an group can quickly become an animation brush by just marking it so. Marking a layer group as animation brush reference exludes it from the canvas,it hides the group. Activating group visibility lets you edit the layers again. Extra bonus is that you store the layers of your brush inside your file. You can edit the layers always (and export) making it a very adjustable option. So the main difference that I propose is that you can add and adjust an animation brush in the CURRENT file, and keep adjusting them without going back to a different window and without having to hide/unhide layers all the time. extra options that might be needed. 1) animation group properties -> set as custom,random,incremental,pressure or angular. ->changeable on the fly 2)a slider in custom brush /predefined brush settings to flip through the frames of an animation brush->quick access/visualization of what a brush is in settings. useful if you have similar animation brushes. just a few thoughts of me on the animation brush process. There might be more solutions.
after some discussion with DmitryK and Animtim it was decided that perhaps the best idea was to be able to specify more precisely the source in the custom brush The custom brush should detect available group layers and if you select a group it will become an animation brush,instead of the WHOLE file,as it does now. So It just limits the number of layers that are considered. This way you can store an animation group in the same file for re-use. And it still should be quite versatile to use as it can still be edited,while a predefined brush cannot. (or at least not easily)
Summary: export group with layers not as projection but as layers to file formats that support that. WISHGROUP: Larger Usability Fixes