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;
}