After the 40.00 UEFN update, physics behavior appears to be inconsistent. In some cases, collision detection fails entirely, causing fast-moving objects to pass through solid geometry.
Please select what you are reporting on:
Unreal Editor for Fortnite
What Type of Bug are you experiencing?
Assets
Steps to Reproduce
Open a UEFN project with physics-enabled objects
Use a small, fast-moving object (e.g. a golf ball 20cm~)
Apply a strong impulse or high velocity to the object
Aim the object toward a static mesh wall or collision surface
Repeat multiple times with high speed
Expected Result
The object should always correctly collide with walls and bounce or stop based on physics settings.
Observed Result
At high speeds, the object intermittently ignores collisions and passes through walls (tunneling effect), making gameplay unreliable.
The issue extends to volume devices as well. At high velocities, the ball experiences tunneling, preventing collision detection and causing events such as OnPropEnterEvent to not trigger.
even after setting “use simple as complex” on meshes used in physics props, we are still seeing collision behave differently than before.
we are seeing vertical (out of plane) movement be introduced to collisions we would expect to remain in-plane. an example of this would be 2 spheres moving in the same XY plane, with no vertical (Z) velocity, colliding and then moving vertically in response.
