Static Mesh的Simple Collision & Complex Collision：
Simple Collision surrounds Static Meshes with relatively simple collision bodies for collision detection; Complex Collision uses the triangular faces of Static Meshes directly as collision bodies, which is more complicated and accurate in collision detection;
Among the related properties of StaticMesh, there are settings for Simple Collision and Complex Collision:
The Project Default here refers to directly using the relevant settings in Project Settings:
Then in the default setting, both Simple and Complex collision bodies are added at the same time. In the case of a player walking and colliding, Simple collision is used, and in the case of a bullet hitting an object, Complex collision is used; this switching depends on Parameters such as TraceComplex in the node are completed:
