Mesh

Description

A class that allows creating or modifying meshes from scripts.

Meshes contain vertices and multiple triangle arrays. See the Procedural example project for examples of using the mesh interface.

The triangle arrays are simply indices into the vertex arrays; three indices for each triangle.

For every vertex there can be a normal, two texture coordinates, color and tangent. These are optional though and can be removed at will. All vertex information is stored in separate arrays of the same size, so if your mesh has 10 vertices, you would also have 10-size arrays for normals and other attributes.

There are probably 3 things you might want to use the modifyable mesh interface for:

1. Building a mesh from scratch: should always be done in the following order: 1) assign vertices 2) assign triangles.

var newVertices : Vector3[];
var newUV : Vector2[];
var newTriangles : int[];
function Start () {
	var mesh : Mesh = new Mesh ();
	GetComponent(MeshFilter).mesh = mesh;
	mesh.vertices = newVertices;
	mesh.uv = newUV;
	mesh.triangles = newTriangles;
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Vector3[] newVertices;
    public Vector2[] newUV;
    public int[] newTriangles;
    void Start() {
        Mesh mesh = new Mesh();
        GetComponent<MeshFilter>().mesh = mesh;
        mesh.vertices = newVertices;
        mesh.uv = newUV;
        mesh.triangles = newTriangles;
    }
}

import UnityEngine
import System.Collections

public class ExampleClass(MonoBehaviour):

	public newVertices as (Vector3)

	public newUV as (Vector2)

	public newTriangles as (int)

	def Start() as void:
		mesh as Mesh = Mesh()
		GetComponent[of MeshFilter]().mesh = mesh
		mesh.vertices = newVertices
		mesh.uv = newUV
		mesh.triangles = newTriangles

2. Modifying vertex attributes every frame: 1) get vertices, 2) modify them, 3) assign them back to the mesh.

function Update () {
	var mesh : Mesh = GetComponent(MeshFilter).mesh;
	var vertices : Vector3[] = mesh.vertices;
	var normals : Vector3[] = mesh.normals;
	for (var i = 0; i < vertices.Length; i++)
		vertices[i] += normals[i] * Mathf.Sin(Time.time);
	mesh.vertices = vertices;
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    void Update() {
        Mesh mesh = GetComponent<MeshFilter>().mesh;
        Vector3[] vertices = mesh.vertices;
        Vector3[] normals = mesh.normals;
        int i = 0;
        while (i < vertices.Length) {
            vertices[i] += normals[i] * Mathf.Sin(Time.time);
            i++;
        }
        mesh.vertices = vertices;
    }
}

import UnityEngine
import System.Collections

public class ExampleClass(MonoBehaviour):

	def Update() as void:
		mesh as Mesh = GetComponent[of MeshFilter]().mesh
		vertices as (Vector3) = mesh.vertices
		normals as (Vector3) = mesh.normals
		i as int = 0
		while i < vertices.Length:
			vertices[i] += (normals[i] * Mathf.Sin(Time.time))
			i++
		mesh.vertices = vertices

3. Continously changing the mesh triangles and vertices: 1) call Clear to start fresh, 2) assign vertices and other attributes, 3) assign triangle indices.

It is important to call Clear before assigning new vertices or triangles. Unity always checks the supplied triangle indices whether they don't reference out of bounds vertices. Calling Clear then assigning vertices then triangles makes sure you never have out of bounds data.

var newVertices : Vector3[];
var newUV : Vector2[];
var newTriangles : int[];
function Update () {
	var mesh : Mesh = GetComponent(MeshFilter).mesh;
	mesh.Clear();
	// Do some calculations...
	mesh.vertices = newVertices;
	mesh.uv = newUV;
	mesh.triangles = newTriangles;
}

using UnityEngine;
using System.Collections;

public class ExampleClass : MonoBehaviour {
    public Vector3[] newVertices;
    public Vector2[] newUV;
    public int[] newTriangles;
    void Update() {
        Mesh mesh = GetComponent<MeshFilter>().mesh;
        mesh.Clear();
        mesh.vertices = newVertices;
        mesh.uv = newUV;
        mesh.triangles = newTriangles;
    }
}

import UnityEngine
import System.Collections

public class ExampleClass(MonoBehaviour):

	public newVertices as (Vector3)

	public newUV as (Vector2)

	public newTriangles as (int)

	def Update() as void:
		mesh as Mesh = GetComponent[of MeshFilter]().mesh
		mesh.Clear()
		mesh.vertices = newVertices
		mesh.uv = newUV
		mesh.triangles = newTriangles

Variables

bindposes	The bind poses. The bind pose at each index refers to the bone with the same index.
blendShapeCount	Returns BlendShape count on this mesh.
boneWeights	The bone weights of each vertex.
bounds	The bounding volume of the mesh.
colors	Vertex colors of the mesh.
colors32	Vertex colors of the mesh.
isReadable	Returns state of the Read/Write Enabled checkbox when model was imported.
normals	The normals of the mesh.
subMeshCount	The number of submeshes. Every material has a separate triangle list.
tangents	The tangents of the mesh.
triangles	An array containing all triangles in the mesh.
uv	The base texture coordinates of the mesh.
uv2	The second texture coordinate set of the mesh, if present.
vertexCount	Returns the number of vertices in the mesh (Read Only).
vertices	Returns a copy of the vertex positions or assigns a new vertex positions array.

Constructors

Mesh	Creates an empty mesh.

Functions

Clear	Clears all vertex data and all triangle indices.
CombineMeshes	Combines several meshes into this mesh.
GetBlendShapeName	Returns name of BlendShape by given index.
GetIndices	Returns the index buffer for the submesh.
GetTopology	Gets the topology of a submesh.
GetTriangles	Returns the triangle list for the submesh.
MarkDynamic	Optimize mesh for frequent updates.
Optimize	Optimizes the mesh for display.
RecalculateBounds	Recalculate the bounding volume of the mesh from the vertices.
RecalculateNormals	Recalculates the normals of the mesh from the triangles and vertices.
SetIndices	Sets the index buffer for the submesh.
SetTriangles	Sets the triangle list for the submesh.

Inherited members