Documentation

Super Crowd — User Manual

1. Overview

Super Crowd is a procedural audience/crowd generation tool provided by SuperStage. It generates non-overlapping randomly distributed crowds within spline-defined enclosed areas using Poisson disk sampling algorithms, and supports terrain snapping.

Core Features

  • Spline boundary — Closed spline defines the crowd distribution area
  • Poisson disk sampling — Bridson algorithm ensures uniform, non-overlapping character spacing
  • Multiple character templates — Supports multiple character meshes + weight-based random assignment
  • Terrain snapping — Ray detection automatically snaps to ground
  • Density/Count dual mode — Controls crowd scale by density or target count

Use Cases

  • Performance venue audience area pre-visualization
  • Event venue crowd density planning
  • Standing audience simulation in front of stage
  • Crowding any arbitrary area

2. Usage

  1. Place a Super Crowd Actor in the scene
  2. After selecting, edit spline control points to enclose a closed area
  3. Adjust density/count parameters
  4. Crowd automatically generated within the enclosed area

Important: The spline must form a closed polygon (end-to-end connected); otherwise the area cannot be calculated.


3. Main Parameters

3.1 Distribution Parameters

Parameter Description
FillMode Fill mode: Density / TargetCount
Density Density (people/m²), used in Density mode
TargetCount Target number of people, used in TargetCount mode
MinSpacing Minimum spacing between characters (cm)
RandomSeed Random seed (same seed produces same distribution)

3.2 Character Templates

Define available character models via the Characters array:

Field Description
Mesh Character Static Mesh (StaticMesh)
Weight Weight (higher = more likely to be selected)
MinScale / MaxScale Random scale range
bRandomYaw Random yaw rotation

3.3 Terrain Parameters

Parameter Description
bSnapToGround Snap to ground
TraceDistance Ray detection distance (cm)
GroundOffset Ground offset (cm)

4. Algorithm Notes

Poisson Disk Sampling (Bridson)

  • Generates uniformly distributed random points within the spline-defined area
  • Ensures distance between any two points is not less than MinSpacing
  • More natural than pure random distribution, no clustering

Area Determination

  • Ray casting method to determine if a point is inside the polygon
  • Shoelace formula for area calculation

Terrain Snapping

  • Cast rays from above each sample point downward
  • Local coordinates → world coordinates → ray detection → world coordinates → local coordinates

5. ISM Components

Uses ISM component pool (up to MAX_CHARACTER_ISM_COUNT components), each character mesh type occupies one ISM component.


6. Usage Tips

  • Recommended density: dense standing 2~4 people/m², spacious 0.5~1 person/m²
  • Character Weight controls proportions, e.g., 70% regular audience + 20% hands up + 10% taking photos
  • Crowd automatically regenerates after modifying spline control points
  • Large crowds (>1000) may affect editor frame rate