Geometry Collection

Modularity and Best Practices

1.A Watertight Modules

Geometry should be watertight and, where
possible, non-intersecting.

Separation of hulls allows more flexibility and control
when Fracturing, while assembly within Blueprints
keeps assets manageable.

• 버튼을 누르면 각 건물 부분들이 애니메이션 처럼 되는데 그 안에서 움직여도 서로 부딪칠때 서로 영향 안 주는 그런걸 의미 하는거 같다.

2.B Gridded Modules
In the case of building modules, we recommend that
pivots obey Unreal's gridding system.

Standardizing widths and heights with the
grid in mind will make life a lot easier.

• 언리얼 x,y,z 이동하는 gridding 시스템을 사용해라.. 이건 뭐 당연한듯.

3.C Material Assignments
Even if your modules share the same textures, you
should apply a unique material ID per material type.

When fracturing occurs, this will generate a 2nd
ID into which you can assign the appropriate
internal material.

• 재질 유형별로 고유 한 재질 ID를 적용

4.D Material Assignments Building Pack Example
This Geometry Collection was composed of 2 meshes.
It shares the same textures, but has
2 separate material types.

This allows both the Stonework and Concrete
to use a unique material for the internal faces.

• FS_StrikeNode_Trigger_1D_Blueprint 둥근 영역이 있는데 그 안에 GC_Building_SFG_L1_ColumnMid_V2 ( GeometryCollection ) 이 부서진다.
  둥근 영역 밖에 있는 때는 안 부서진다.

• Material 이 두개 있는데 한개인 것처럼 부서진다.

5.E Material Assignments Building Pack Example
5 module packs make up
this building facade. Each pack has
multiple material instances applied.

Converting to a Geometry Collection will
consolidate any shared materials
to a single ID and lower draw calls.

• 빌딩이 5개 합쳐져서 복잡한데 Geometry Collection 으로 변환하면 뭐 좋다.

6. F Single Modules & Combined Building Pack Example

Meshes can be converted into Geometry Collections
in any combination.

Small modules are more flexible in terms of placement, but
risk high draw calls, visible seams, and repetition when duplicated
across a structure. Larger, combined modules are less flexible,
but can be fractured and clustered to hide seams.

• Geometry Collection 합쳐진다.

Geometry Collection

Collision Types

2.A Analytic Collisions Sphere & Cube
3.B Analytic Collisions Simulation
4.C Collision Reduction Percentage Simulation
Analytic collision volumes provide a
simple representation of rigid bodies.

Boxes wrap the body in a similar way to a
bounding box, whereas Spheres and Cylinders
are positioned to fit within the rigid body.

• 콜리전 영역은 구 , 실린더를 사용하는게 쉽다.
• 장점 빠른 계산 , 적은 메모리 반면 부정확성
• box 가 Spheres or Cylinders 보다 빠르다.

5.D Implict Collisions evel Set Volumes
6.E Implicit Collisions Simulation

A Level Set Volume samples a rigid body
using a voxelized grid, and generates a signed
distance field for the geometry.

The resolution of the Level Set Volume can be specified
on the asset's Min/Max Level Set Resolution settings.

• 장점 빠른 속도 , 퍼포먼스 조절 가능 반면 많은 메모리 사용