vector | The vector to project on the plane. |

planeNormal | The normal which defines the plane to project on. |

**Vector3**
The orthogonal projection of `vector`

on the plane.

Projects a vector onto a plane.

For a given plane described by `planeNormal`

and a given vector `vector`

,
Vector3.ProjectOnPlane generates a new vector orthogonal to `planeNormal`

and parallel to the plane.
Note: `planeNormal`

does not need to be normalized.

''The red line represents `vector`

, the yellow line represents `planeNormal`

, and the blue line represents the projection of `vector`

on the plane.''

The script example below makes `Update`

generate a `vector`

position, and a `planeNormal`

normal. The Vector3.ProjectOnPlane static method receives the arguments and returns the Vector3 position.

using System.Collections; using System.Collections.Generic; using UnityEngine;

// Vector3.ProjectOnPlane - example

// Generate a random plane in xy. Show the position of a random // vector and a connection to the plane. The example shows nothing // in the Game view but uses Update(). The script reference example // uses Gizmos to show the positions and axes in the Scene.

public class Example : MonoBehaviour { private Vector3 vector, planeNormal; private Vector3 response; private float radians; private float degrees; private float timer = 12345.0f;

// Generate the values for all the examples. // Change the example every two seconds. void Update() { if (timer > 2.0f) { // Generate a position inside xy space. vector = new Vector3(Random.Range(-1.0f, 1.0f), Random.Range(-1.0f, 1.0f), 0.0f);

// Compute a normal from the plane through the origin. degrees = Random.Range(-45.0f, 45.0f); radians = degrees * Mathf.Deg2Rad; planeNormal = new Vector3(Mathf.Cos(radians), Mathf.Sin(radians), 0.0f);

// Obtain the ProjectOnPlane result. response = Vector3.ProjectOnPlane(vector, planeNormal);

// Reset the timer. timer = 0.0f; } timer += Time.deltaTime; }

// Show a Scene view example. void OnDrawGizmosSelected() { // Left/right and up/down axes. Gizmos.color = Color.white; Gizmos.DrawLine(transform.position - new Vector3(2.25f, 0, 0), transform.position + new Vector3(2.25f, 0, 0)); Gizmos.DrawLine(transform.position - new Vector3(0, 1.75f, 0), transform.position + new Vector3(0, 1.75f, 0));

// Display the plane. Gizmos.color = Color.green; Vector3 angle = new Vector3(-1.75f * Mathf.Sin(radians), 1.75f * Mathf.Cos(radians), 0.0f); Gizmos.DrawLine(transform.position - angle, transform.position + angle);

// Show the projection on the plane as a blue line. Gizmos.color = Color.blue; Gizmos.DrawLine(Vector3.zero, response); Gizmos.DrawSphere(response, 0.05f);

// Show the vector perpendicular to the plane in yellow Gizmos.color = Color.yellow; Gizmos.DrawLine(vector, response);

// Now show the input position. Gizmos.color = Color.red; Gizmos.DrawSphere(vector, 0.05f); Gizmos.DrawLine(Vector3.zero, vector); } }