inverse
The inverse of this matrix. (Read Only)
Read time 1 minuteLast updated 11 days ago
Definition
- Type: Property
- Namespace: UnityEngine
- Assembly: UnityEngine.CoreModule
public readonly Matrix4x4 inverse { get; }
Remarks
Inverted matrix is such that if multiplied by the original would result in Matrix4x4.identity matrix.
If as matrix transforms vectors in a particular way, then the inverse matrix can transform them back. For example, Transform's Transform.worldToLocalMatrix and Transform.localToWorldMatrix are inverses of each other.
For regular 3D transformation matrices, it can be faster to use Matrix4x4.Inverse3DAffine method.
You can not invert a matrix with a Matrix4x4.determinant of zero. If you attempt this, returns Matrix4x4.zero instead.
inverseusing UnityEngine;// Stretch a mesh at an arbitrary angle around the X axis[RequireComponent(typeof(MeshFilter))]public class ExampleScript : MonoBehaviour{ // Angle and amount of stretching public float rotAngle = 30; public float stretch = 3; MeshFilter mf; Vector3[] origVerts; Vector3[] newVerts; void 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]; } void Update() { // Create a rotation matrix from a Quaternion Quaternion rot = Quaternion.Euler(rotAngle, 0, 0); Matrix4x4 m = Matrix4x4.TRS(Vector3.zero, rot, Vector3.one); // Get the inverse of the matrix: undo the rotation Matrix4x4 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 Vector3 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); } // Assign the transformed vertices to the mesh mf.mesh.vertices = newVerts; }}
Additional Resources: Matrix4x4.Inverse3DAffine, Matrix4x4.determinant.