Turning on batching of sphere casts when colliding against complex gives incorrect results.

Affects debug output and vehicle wheels and body movement.

The issue is with the batch query mode which doesn't use world queries but a lesser used SweepComponent functionality. I believe the SweepComponent functionality has a bug.


The workaround is to turn off batching for now, which is actually already the default in this version and all that come after.

The customer however was wanting to switch it on.

Steps to Reproduce

This was raised by a customer and is most easily reproduced by using the vehicle system.

Run the VehicleBPTemplate

Change the sportscars front and rear wheel setups to

Sweep Shape to Spherecast

Sweep Type to ComplexSweep

This is in SportsCar_WheelsFront & SportsCar_WheelsRear blueprints

found at Content/VehicleTemplate/Blueprints/SportsCar


p.Chaos.DebugDraw.Enabled 1

p.Vehicle.ShowWheelCollisionNormal 1

p.Vehicle.BatchQueries 1

When you drive the vehicle the resulting output from the wheel traces will be all over the place rather than a nice straight line. See videos:-

Not working

[Link Removed]


Should behave like this

[Link Removed]




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ComponentUE - Simulation - Physics
Affects Versions5.2
Target Fix5.5
CreatedSep 19, 2023
UpdatedFeb 27, 2024