Started with the “First Person Template” as a foundation for the project. I was handed a 3D model of a subway station built in Autodesk Revit. Imported it into 3D Studio MAX 2017 for UV mapping and UCX collision assignment. The model was centered around 1800 meters from the origo in 3D MAX. Exporting walls, floors and ceilings with their corresponding collision worked as expected in Unreal.
The problems started when modeling collision for the stairs. Every import from 3D MAX either had missing faces or random distortions and gaps. After a while I tried moving the whole stair model to 0,0(origo) into 3D max before exporting the FBX. When brought into Unreal the collision mesh finally looked right. The render mesh itself never had any problems, only the UCX collision mesh.alt text
Attached are both a 3D MAX 2014 file of the offending stairs model and the exported FBX file.
I have been forced to restart the project starting with moving the whole scene in 3DS MAX to the center of Origo. The collision distortions are mostly fixed, but can still appear if the collision mesh is too thin(like modelling a very thin box for instance). For now this work around seems to hold, but it would be nice to know what is causing these problems.