godot-physics

1# Godot Physics (4.x, 2D + 3D)
2 
3Pick the right physics body, wire up collision layers/masks, detect overlaps, and cast
4rays. Concepts apply to both 2D and 3D (swap the `2D`/`3D` suffix). Targets
5**Godot 4.7**. In 3D, projects created with Godot 4.6 or later run **Jolt Physics** by
6default; older projects keep **GodotPhysics3D** unless someone switched them. 2D always
7uses Godot's own 2D engine.
8 
9## When to use
10 
11- Use when choosing between body types, setting collision layers/masks so the right
12  things collide, detecting overlaps (triggers, hurtboxes) with `Area`, applying
13  forces/impulses to a `RigidBody`, or casting rays for line-of-sight/ground checks.
14 
15**When *not* to use:** kinematic character controllers (`move_and_slide`) →
16`godot-2d-movement`; tile collision setup → `godot-tilemap`; tuning the *feel* of physics
17(timestep, mass, jitter) → `physics-tuning`.
18 
19## Core workflow
20 
211. **For 3D, check which engine runs** before debugging behavior: Project Settings >
22   Physics > 3D > Physics Engine (`[physics]` `3d/physics_engine="Jolt Physics"` in
23   `project.godot`). Projects created in 4.6+ get Jolt written there by default; with no
24   such line (`DEFAULT`) the engine is GodotPhysics3D. The API is the same, but joints,
25   ray-cast face indices, kinematic contacts, and collision margins behave differently
26   (see Pitfalls).
272. **Choose the body type:**
28   - `StaticBody` — never moves (floors, walls). Collides, no simulation.
29…