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.
Additional resources: MultiplyPoint, MultiplyVector.
using UnityEngine;
public class ExampleScript : MonoBehaviour { // Stretch a mesh at an arbitrary angle around the X axis.
// Angle and amount of stretching. float rotAngle; float stretch;
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 (ie, to 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. 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; } }