Transforms a position by this matrix (fast).

Returns a position `v`

transformed by the current transformation matrix.
This function is a faster version of MultiplyPoint; but it can only
handle regular 3D transformations. `MultiplyPoint`

is slower, but can handle
projective transformations as well.

See Also: MultiplyPoint, MultiplyVector.

// 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; } }