Version: 2023.1
LanguageEnglish
  • C#

Matrix4x4.Perspective

Suggest a change

Success!

Thank you for helping us improve the quality of Unity Documentation. Although we cannot accept all submissions, we do read each suggested change from our users and will make updates where applicable.

Close

Submission failed

For some reason your suggested change could not be submitted. Please <a>try again</a> in a few minutes. And thank you for taking the time to help us improve the quality of Unity Documentation.

Close

Cancel

Declaration

public static Matrix4x4 Perspective(float fov, float aspect, float zNear, float zFar);

Parameters

fov Vertical field-of-view in degrees.
aspect Aspect ratio (width divided by height).
zNear Near depth clipping plane value.
zFar Far depth clipping plane value.

Returns

Matrix4x4 The projection matrix.

Description

Create a perspective projection matrix.

Projection matrices in Unity follow OpenGL convention, i.e. clip space near plane is at z=-1, and far plane is at z=1.

The returned matrix embeds a z-flip operation whose purpose is to cancel the z-flip performed by the camera view matrix. If the view matrix is an identity or some custom matrix that doesn't perform a z-flip, consider multiplying the third column of the projection matrix (i.e. m02, m12, m22 and m32) by -1.

Note that depending on the graphics API used, projection matrices in shaders can follow different convention, for example the D3D-style clip space has near plane at zero and far plane at one; and "reversed Z" projection has near plane at one and far plane at zero. To calculate projection matrix value suitable for passing to shader variables, use GL.GetGPUProjectionMatrix.

using UnityEngine;

public class ExampleScript : MonoBehaviour { void Start() { // create projection matrix: 60 FOV, square aspect, // near plane 1, far plane 100 var matrix = Matrix4x4.Perspective(60, 1, 1, 100); // will print: // 0.20000 0.00000 0.00000 0.00000 // 0.00000 0.20000 0.00000 0.00000 // 0.00000 0.00000 -0.02020 -1.02020 // 0.00000 0.00000 0.00000 1.00000 Debug.Log("projection matrix\n" + matrix);

// get shader-compatible projection matrix value var shaderMatrix = GL.GetGPUProjectionMatrix(matrix, false); // on a Direct3D-like graphics API, will print: // 0.20000 0.00000 0.00000 0.00000 // 0.00000 0.20000 0.00000 0.00000 // 0.00000 0.00000 0.01010 1.01010 // 0.00000 0.00000 0.00000 1.00000 Debug.Log("shader projection matrix\n" + shaderMatrix); } }