PhysicsWorld.transformPlane

Description

Controls the transform plane that the world uses when writing transforms. See PhysicsWorld.transformWriteMode.

Set this property to run 2D physics in 3D space, for example to lay a 2D world flat on the ground.

 using Unity.Collections;
 using UnityEngine;
 using Unity.U2D.Physics;

 public class CreateXZPlane : MonoBehaviour
 {
     public PhysicsWorld world;

     private void Start()
     {
         // Create a world with a transform plane of XZ, which is the floor in 3D space.
         PhysicsWorldDefinition worldProperties = new PhysicsWorldDefinition
         {
             transformPlane = PhysicsWorld.TransformPlane.XZ,
             gravity = Vector2.zero
         };
         world = PhysicsWorld.Create(worldProperties);

         // Create a square boundary.
         PhysicsBody boundary = world.CreateBody();
         using NativeList<Vector2> extentPoints = new NativeList<Vector2>(Allocator.Temp)
         {
             new(-4f, 4f),
             new(4f, 4f),
             new(4f, -4f),
             new(-4f, -4f)
         };
         ChainGeometry boundaryWalls = new ChainGeometry(extentPoints.AsArray());
         boundary.CreateChain(boundaryWalls, PhysicsChainDefinition.defaultDefinition);

         // Create a body and set it moving.
         PhysicsBodyDefinition bodyDefinition = new PhysicsBodyDefinition();
         bodyDefinition.type = PhysicsBody.BodyType.Dynamic;
         bodyDefinition.linearVelocity = new Vector2(7.3f, 5.7f);
         bodyDefinition.angularVelocity = 0f;
         PhysicsBody body = world.CreateBody(bodyDefinition);

         // Add a shape with a bouncy material.
         body.transformObject = transform;
         PhysicsShapeDefinition shapeDefinition = new PhysicsShapeDefinition();
         shapeDefinition.surfaceMaterial = new PhysicsShape.SurfaceMaterial { bounciness = 1f, friction = 0f };
         body.CreateShape(new CircleGeometry { radius = 1f }, shapeDefinition);
     }

     private void OnDisable()
     {
         world.Destroy();
     }
 }