Thanks for responding. For further clarity: the latency in question isn’t between a player’s motion and the actions in game, it’s between the game’s reported orientation of the motioncontroller and the animBP’s animation graph (IK solver).
I understand that disabling low latency update will cause the final SteamVR motioncontroller orientation to be fixed to where it was at the beginning of the frame. In other words this means the physical position of the player’s hands will be different from in-game by a few milliseconds. This is totally fine with me. The problem is that for some reason when I copy the transform of the motioncontroller into my relevant hand end effector transform (done in pre-physics tick) in the player model animBP, it doesn’t seem to update the animBP pose before render. It is consistently one frame behind. I just want the hands of my animBP to match up with the position of my hand components, and that doesn’t happen with either low latency update turned on or off for both hands.
I’ve looked into the flow of the engine, and it seems that the particular skeletal mesh’s updatePose gets called just before render happens. Which means that for some reason, the logical flow:
(SteamVR plugin updates motioncontroller location) → (set hand target in animBP) → (update animBP’s pose)
results in the animBP taking the hand target from the previous frame, and producing a pose to render for this frame that is out of date. Unfortunately I have no way of debugging the information passed in with the animation blueprints, as there are no symbols in VS 2015 breakpointing those delegates, and you can’t breakpoint in an animation graph.