I would also like to know. It’s weird that you can use animation composite in Animation blueprints in the sequencer animation track for a skeletal mesh, but not in blend spaces. Also in the asset browser panel of the blend space, the animation composite is visible next to the regular animations. Why would it be visible if we cannot use it ?
So, I have a blend space and 2 animations I want to blend between, an idle and an walk. The walk is an animation composite so I cannot use it inside the blend space. The editor wont allow this.
Open the original animation that this animation composite is based on, move the red cursor to where you want the animation to begin or end, then right click and select “Remove from…” to remove the unwanted frames. This will edit the animation file, so I recommend making a copy before using this option.
That’s how I got a new animation and never left UE4
For me, this works, because my composite only has one animation.