Settings

This section covers the authoring you configure once per scene — simulation limits and LOD, the spatial map volume, gravity sources — plus the body types you place in that setup.

All of these use authoring components on GameObjects inside a subscene, then bake into ECS entities. See Getting Started for the setup workflow.

Pages in this section

Page	Covers
Physics settings and LOD	`PhysicsSettingsAuthoring`, capacity limits, LOD tiers, push-out
Spatial map	`SpacialMapAuthoring`, grid bounds, object-to-object collision region
Gravity	Directional and spherical `GravitySourceAuthoring`
Dynamic	Simulated spheres — gravity, friction, collisions, surfaces
Kinematic	Rigid movers and triggers on an update interval
Static	Fixed colliders and triggers baked into the map once
Surface	Ground, walls, and bounds that all dynamics hit every frame

Body types at a glance

Type	Authoring	Shapes	Affected by gravity & friction	Object-to-object collisions	Surface collision
Dynamic	`DynamicBodyAuthoring`	Sphere only	Yes	Yes (inside spatial map)	Yes (every substep)
Kinematic rigid	`KinematicBodyAuthoring` (`IsTrigger = false`)	Sphere, capsule	No	Pushes dynamics; updated in map each substep	Intersection only (no impulse)
Kinematic trigger	`KinematicBodyAuthoring` (`IsTrigger = true`)	Sphere, capsule	No	Intersection checks on `UpdateInterval`	Intersection only
Static rigid	`StaticBodyAuthoring` (`IsTrigger = false`)	Sphere, capsule	No	Pushes dynamics; added to map once	No
Static trigger	`StaticBodyAuthoring` (`IsTrigger = true`)	Sphere, capsule	No	Intersection checks when dynamics/kinematics pair against it	No
Surface	`SurfaceBodyAuthoring`	Sphere, plane, box, reverse sphere	No	No	Collides all non-static bodies each substep

Dynamic bodies are spheres only. Kinematic and static bodies support sphere and capsule. Surfaces use specialized shapes (plane, box, reverse sphere, etc.). See known limitations on the home page.

Scene view

Every body authoring draws its collider shape as a wireframe in the Unity Scene view when the GameObject is selected. The preview updates live as you change ColliderScale, ColliderLocalPosition, Collider, transform scale, and other Inspector fields — so you can align colliders with meshes without entering Play mode.

Body kind	Wireframe color
Rigid (dynamic, kinematic rigid, static rigid, surface)	Yellow
Trigger (kinematic or static)	Blue

Surfaces draw the active shape (plane grid, box cage, or sphere) from the transform. Individual pages below describe shape-specific gizmo behavior.

Rigid vs trigger

Every kinematic and static body is either rigid or trigger, controlled by IsTrigger on the authoring component.

	Rigid	Trigger
Physical response	Applies push-out and velocity changes to dynamic bodies	None — overlap is recorded as intersection data only
Forces	Rigid kinematic/static bodies are not driven by gravity or collision impulses	Same
Typical use	Moving platforms, doors, fixed walls	Pickup zones, proximity checks, gameplay events

Triggers still participate in pair collection and CollisionData slots when overlaps occur. Read results in custom systems via ICollisionJob or inspect CollisionsSingleton.

Spatial map vs surface

Two separate collision paths exist:

Object-to-object — dynamic and kinematic bodies inside the volume defined by SpacialMapAuthoring are inserted into grid cells and tested against neighbors. Outside the map, bodies still get gravity and surface contact, but not pairwise object collisions.
Surface — every dynamic body is tested against the scene surface every substep, regardless of LOD or map cell. Kinematic bodies (including triggers) also get surface intersection tests; triggers receive contact data without physical push-out.

For map internals, see Spatial map and How it works.

Body count limit

Import respects MaxEntitiesCount on PhysicsSettingsAuthoring. Bodies beyond the cap are ignored for the simulation. Plan capacity when spawning large crowds.

What to read next

Topic	Page
First scene setup	Getting Started
Import, fixed step, LOD	How it works
Runtime spawning	Builders
React to collisions and triggers	Custom jobs