Matrix4x4.MultiplyPoint3x4

function MultiplyPoint3x4 (v : Vector3) : Vector3

Description

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.

JavaScript
    // 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 example : 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;
}
}

import UnityEngine
import System.Collections

class example(MonoBehaviour):

public rotAngle as single

public stretch as single

private mf as MeshFilter

private origVerts as (Vector3)

private newVerts as (Vector3)

def Start():
mf = GetComponent[of MeshFilter]()
origVerts = mf.mesh.vertices
newVerts = array[of Vector3](origVerts.Length)

def Update():
rot as Quaternion = Quaternion.Euler(rotAngle, 0, 0)
m as Matrix4x4 = Matrix4x4.TRS(Vector3.zero, rot, Vector3.one)
inv as Matrix4x4 = m.inverse
i as int = 0
while i < origVerts.Length:
pt as Vector3 = m.MultiplyPoint3x4(origVerts[i])
pt.y *= stretch
newVerts[i] = inv.MultiplyPoint3x4(pt)
i++
mf.mesh.vertices = newVerts