frinky-engine

Physics

Physics is powered by BepuPhysics 2.

Use This When

Use the physics system when you need:

• rigidbody simulation
• trigger volumes
• collisions and collision callbacks
• a built-in character controller
• raycasts or shape queries

Common Setups

Static world geometry

Use:

• a collider on the entity
• optionally a RigidbodyComponent with MotionType = Static

Collider-only entities are supported as true static collidables and triggers.

Dynamic physics object

Use:

• RigidbodyComponent with MotionType = Dynamic
• an appropriate collider

This is the normal setup for movable simulated props.

Kinematic mover

Use:

• RigidbodyComponent with MotionType = Kinematic
• an appropriate collider

Use this for scripted moving platforms or objects that should push dynamic bodies without being force-driven themselves.

Character controller

Use:

• RigidbodyComponent with MotionType = Dynamic
• CapsuleColliderComponent
• CharacterControllerComponent

Add SimplePlayerInputComponent if you want the built-in input-driven movement path.

Important:

• the CapsuleColliderComponent must be the first enabled collider on the entity

Minimal Trigger Example

using FrinkyEngine.Core.ECS;

public class PickupZone : Component
{
    public override void OnTriggerEnter(Entity other)
    {
        FrinkyLog.Info($"{other.Name} entered the zone");
    }
}

To make this work:

1. Add a collider to the entity.
2. Set IsTrigger = true.
3. Make sure another collider can overlap it.

Rigidbodies

Motion Type	Use it for
Dynamic	fully simulated objects
Kinematic	scripted movers that still affect dynamic bodies
Static	immovable collision surfaces

Scene gravity

Scene gravity comes from Scene.PhysicsSettings.Gravity. Runtime gravity changes apply immediately, including changes made through the physics_gravity console CVar.

Colliders

Collider	Use it for
BoxColliderComponent	boxes, walls, rectangular triggers
SphereColliderComponent	radial triggers and simple round objects
CapsuleColliderComponent	characters and capsule-like actors
MeshColliderComponent	static or kinematic triangle-mesh collision

All colliders support:

• Center offset from the entity origin
• IsTrigger for overlap-only behavior

MeshColliderComponent builds a triangle mesh from MeshPath or, if UseMeshRendererWhenEmpty is enabled, from the sibling MeshRendererComponent.

Raycasting

Use raycasts to check what is under a cursor, in front of an entity, or between two points.

using FrinkyEngine.Core.Physics;

if (Physics.Raycast(origin, direction, 100f, out var hit))
{
    FrinkyLog.Info($"Hit {hit.Entity.Name} at {hit.Point}");
}

Use RaycastAll when you need every hit instead of the closest one.

Editor Workflow

The editor includes physics helpers:

• Add Physics shortcuts in the hierarchy and inspector
• F8 collider wireframe preview
• F9 collider edit mode for resizing and repositioning collider shapes

Notes

• Dynamic mesh colliders are not supported.
• MeshColliderComponent is best for static or kinematic collision.
• The built-in character controller expects the capsule collider setup described above, with the capsule as the first enabled collider.

See Also

• Choosing Components for setup selection
• Editor Guide for collider editing and quick-add flow

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