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Matrix4x4.inverse

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public var inverse: Matrix4x4;
public Matrix4x4 inverse;

Description

The inverse of this matrix (Read Only).

Inverted matrix is such that if multiplied by the original would result in identity matrix.

If some matrix transforms vectors in a particular way, then the inverse matrix can transform them back. For example, Transform's worldToLocalMatrix and localToWorldMatrix are inverses of each other.

	// Stretch a mesh at an arbitrary angle around the X axis.
	
	// Angle and amount of stretching.
	var rotAngle: float;
	var stretch: float;
	
	
	private var mf: MeshFilter;
	private var origVerts: Vector3[];
	private var newVerts: Vector3[];
	
	
	function Start () {
		// Get the Mesh Filter component, save its original vertices
		// and make a new vertex array for processing.
		mf = GetComponent.<MeshFilter>();
		origVerts = mf.mesh.vertices;
		newVerts = new Vector3[origVerts.Length];
	}
	
	
	function Update () {
		// Create a rotation matrix from a Quaternion.
		var rot = Quaternion.Euler(rotAngle, 0, 0);
		var m = Matrix4x4.TRS(Vector3.zero, rot, Vector3.one);
		
		// Get the inverse of the matrix (ie, to undo the rotation).
		var inv = m.inverse;
		
		// For each vertex...
		for (var i = 0; i < origVerts.Length; i++) {
			// Rotate the vertex and scale it along its new Y axis.
			var pt = m.MultiplyPoint3x4(origVerts[i]);
			pt.y *= stretch;
			
			// Return the vertex to its original rotation (but with the
			// scaling still applied).
			newVerts[i] = inv.MultiplyPoint3x4(pt);
		}
		
		// Copy the transformed vertices back to the mesh.
		mf.mesh.vertices = newVerts;
	}
using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour { public float rotAngle; public float stretch; private MeshFilter mf; private Vector3[] origVerts; private Vector3[] newVerts; void Start() { mf = GetComponent<MeshFilter>(); origVerts = mf.mesh.vertices; newVerts = new Vector3[origVerts.Length]; } void Update() { Quaternion rot = Quaternion.Euler(rotAngle, 0, 0); Matrix4x4 m = Matrix4x4.TRS(Vector3.zero, rot, Vector3.one); Matrix4x4 inv = m.inverse; int i = 0; while (i < origVerts.Length) { Vector3 pt = m.MultiplyPoint3x4(origVerts[i]); pt.y *= stretch; newVerts[i] = inv.MultiplyPoint3x4(pt); i++; } mf.mesh.vertices = newVerts; } }