How do I update positions between simulation steps?

[jf908]

I am making a bevy game which uses fixed timestep physics for determinism reasons. However, I also want to be able to move sensors and ray cast on them between frames.

Is it possible to update the position of a Collider + Sensor (which should have no impact on the rest of the physics simulation) and also cast rays on it in between physics simulation ticks? I have tried running the apply_collider_user_changes system on Update which does update the sensor's debug position the ray cast doesn't seem to take this into account. The raycast strangely only detects the area which overlaps between the sensor's position during the simulation and it's current position.

Why does this happen? Is there a part of the simulate step that is important for collision detection?

[jf908]

Of course I run into a solution moments after positing this question despite thinking on this problem for days 😄.

Running context.update_query_pipeline(); in an Update system after apply_collider_user_changes properly updates the position for collision, solving this issue.