Week 8 - Map Collision Failure and FAB Solution

I had my first major technical difficulty of the project this week. I made the game map in Blender and then exported it as a set of individual mesh pieces in order to import them into UE5. The next step was to generate collision in UE5 - when the collision setting on the whole map was set to "Convex Collision", and the maximum detail was selected all mesh components were highlighted, and it seemed like it would run. However the collision generation was very time consuming and crashed two different machines with blue screen of death in addition to crashing Unreal on numerous occasions before even starting to get the crash.

After trying to fix this problem I realized the issue. Convex collision in UE5 creates separate convex collision shapes for each individual mesh object within a piece of geometry, and the 100 separate meshes I had imported from blender were forcing UE5 to calculate 100 different convex collision meshes simultaneously. It seems this does not compute properly past about ten separate pieces, and even when the collision finally generated it was not accurately enough aligned with the pieces of the geometry for the player to walk on, and they would fall through floors.

I ended up taking a FAB asset pre-built forest terrain level on the UE5 asset store that already had collision defined within it. I then removed all of the nature assets it contained and placed my own models upon the floor with the use of the foliage tool. Although it was the best solution considering the time constraint this drastically altered the appearance of the map from a flat architectural city into rolling terrain which removed the feel of the post-human city and changed it into the forest. For a later project I would use UE5's Landscape tools that handle walkability native without the risky export-import-collision technique that caused issues.