Draw a debug visualization of LowLevelPhysics2D API objects

Note: This documentation is about writing C# scripts using the LowLevelPhysics2D API. To use 2D physics in the Unity Editor using components like the Rigidbody 2D component, refer to 2D physics instead.

To help you visualize 2D physics objects during development, Unity automatically draws the shapes you create with the LowLevelPhysics2D API.

Unity draws the shapes automatically in the Unity Editor. You can also enable Unity drawing the shapes in development buildsA development build includes debug symbols and enables the Profiler. More info
See in Glossary.

Configure debug drawing

Unity draws your shapes automatically in the SceneA Scene contains the environments and menus of your game. Think of each unique Scene file as a unique level. In each Scene, you place your environments, obstacles, and decorations, essentially designing and building your game in pieces. More info
See in Glossary view, the Game view, and when you enter Play mode.

To configure debug drawing, follow these steps:

1. Select the GameObjectThe fundamental object in Unity scenes, which can represent characters, props, scenery, cameras, waypoints, and more. A GameObject’s functionality is defined by the Components attached to it. More info
   See in Glossary with a public PhysicsWorldDefinition component. For more information, refer to Create a physics world.
2. In the InspectorA Unity window that displays information about the currently selected GameObject, asset or project settings, allowing you to inspect and edit the values. More info
   See in Glossary window, configure the properties that start with Draw. For example Draw Options selects which features to draw, and Draw Colors sets the colors Unity uses.

To set a different color for a specific shape, follow these steps:

1. Select a GameObject with a public PhysicsShapeDefinition component. For more information, refer to Create a physics object.
2. In the Inspector window, set Custom Color.

To configure the properties in your C# script instead, adjust the similarly named properties of your PhysicsWorldDefinition, PhysicsBodyDefinition, or PhysicsShapeDefinition objects.

Enable debug drawing in a development build

To draw in a Player build, follow these steps:

1. Make sure your target build platform supports compute shaders.
2. Create a Physics Low Level Settings 2D asset. For more information, refer to Configure global 2D physics settings.
3. In the Inspector window of the asset, enable Draw In Build.

Draw your own shapes

To draw your own shapes, use the Draw methods of the world object. For example:

// Get the main physics world.
PhysicsWorld world = PhysicsWorld.defaultWorld;

// Draw a line from the origin to (30, 40) in "cornflower blue".
world.DrawLine(Vector2.zero, new Vector2(30f, 40f), Color.cornflowerBlue);

// Draw a circle from the origin to (30, 40) in "forest green".
world.DrawCircle(new Vector2(30f, 40f), 2f, Color.forestGreen);

// Draw a point with a 3 pixel radius at (-5, 10) in "gold".
world.DrawPoint(new Vector2(-5f, 10f), 3f, Color.gold);

Shapes only last for one frame. To draw them for longer, use the lifetime property.

// Set lifetime as 5 seconds.
const float lifeTime = 5f;

// Draw a circle at a specific position in blue for 5 seconds.
world.DrawGeometry(circleGeometry, physicsTransform, Color.cornflowerBlue, lifeTime);

Additional resources

• Creating physics objects with the LowLevelPhysics2D API
• PhysicsCore2D repository on GitHub
• World definition reference for the LowLevelPhysics2D API
• Physics Low Level Settings 2D asset Inspector window reference