Currently it is a lot of work if you want to make a transition between two states of multiple layers - especially if a lot of properties change, because you have to create a new response for every property.
I'd like to have a new response type, where I select the "final state" in a special mode: Here only that layer can be interacted with (all other layers are disabled). I can drag it around on the canvas or edit all its properties directly in the inspector panel to configure the "final state".
All properties I change are compared to the layer's original state and then automatically selected for animation.
This mimicks the behavior of other animation software, where this kind of behavior can be achieved very easily.
GIF: Animation I want to achieve (Scaling is not an option, because not all layers scale, but change size and position arbitrarily. Also other properties like opacity wouldn't be affected by simple scaling.)
Possible solution (just a quick mockup, pretty sure that's not the best way to do it! ;) Should only work as a discussion starter)
1. New Response: Auto
2. Response was selected: You need to select the layer and configure the desired "final state".
3. Configuring "final state": The sidebar changed to the layer's inspector panel, you see and can edit all properties or drag the selected layer on the canvas to the desired final position. Interaction with other layers on the canvas is disabled in this mode.
4. Review of "final state": All properties of the layer, that have been changed, are displayed. When this response is triggered, ProtoPie animates between the default state (the state, the layer has on the canvas) and the "final state" (defined in the response's configuration mode).