MeshCollider

Description

The MeshCollider class implements a collision volume that precisely matches the shape of a 3D mesh. It provides the most accurate collision detection for complex shapes but is typically more computationally expensive than primitive colliders like Box, Sphere, or Capsule.

Namespace

Universe.Core

Properties

Property	Type	Description
trigger	bool	When true, the collider acts as a trigger that detects overlaps but doesn’t create physical collisions
convex	bool	When true, the mesh is treated as a convex shape, allowing it to be used as a dynamic collider
attitude	Attitude	The physical material properties of the collider (affects bounce, friction, etc.)

Methods

OnInit

void OnInit()

Called when the script initializes. Registers the mesh collider with the physics system.

Example Usage

// Create a detailed terrain collider
MeshCollider terrainCollider = new MeshCollider();
terrainCollider.trigger = false; // Solid physical collider
terrainCollider.convex = false; // Complex concave shape
terrainCollider.attitude = Attitude.Natural; // Standard physics properties

// Create a convex collider for a rock
MeshCollider rockCollider = new MeshCollider();
rockCollider.trigger = false;
rockCollider.convex = true; // Make it suitable for physics interactions
rockCollider.attitude = Attitude.SemiBouncing; // Slightly bouncy

// Create a trigger zone with complex shape
MeshCollider triggerZone = new MeshCollider();
triggerZone.trigger = true; // Just for overlap detection
triggerZone.convex = false; // Can be any shape when used as trigger

Technical Details

• For non-trigger colliders, the collision mesh uses the same geometry as the visual mesh of the object
• When convex is true, the mesh is treated as if it were a convex hull of the original shape
• Convex mesh colliders can be used with dynamic physics objects (those with Physics component)
• Concave (non-convex) mesh colliders can only be used with static objects unless they’re triggers
• Mesh colliders provide the most accurate collision detection but at a higher performance cost

Use Cases

• Complex terrain or level geometry
• Detailed props and environment objects
• Custom-shaped trigger areas
• Static world objects with irregular shapes
• Convex dynamic objects when primitive colliders aren’t sufficient

Notes

• For performance reasons, use simpler colliders (Box, Sphere, Capsule) when possible
• Very high-poly meshes should be simplified for collision to improve performance
• For characters and most dynamic objects, Capsule or Box colliders are recommended
• Concave mesh colliders with many polygons can significantly impact physics performance
• Using many mesh colliders can increase memory usage and physics computation cost

Related Components

• Alternative to BoxCollider.cs, SphereCollider.cs, and CapsuleCollider.cs
• Works with Physics.cs for physical interactions

Dependencies

• Uses ColliderUtil.AddMeshCollider() to register with the physics system