I have this issue when I import a house in Unreal 4 created with Reality Creation:
In Meshlab the same mesh looks fine:
This house is as big as a chair. My suspicion is that the very small scale causes these artifacts in Unreal 4.
It looks like some precision loss.
I tried to scale the house in Blender but it did not solved the artifacts visible in Unreal 4.
I also tried to scale it when exporting from Reality Capture. Still not solved.
Any tip is appreciated.
Thank you !