The Unity script below demonstrates how to create a Mesh (in this case a Cube) purely through code.
Simply, create a new Scene, add this script to the Main Camera, and run.
I’ve tested this script using the ‘PC, Mac & Linux Standalone’ Platform option, in ‘Build Settings’ (it should however, work fine on other platforms).
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//Create Mesh in code using UnityEngine; using System.Collections; public class UnityMeshCreator : MonoBehaviour { GameObject _cube; void Start () { //1) Create an empty GameObject with the required Components _cube = new GameObject("Cube"); _cube.AddComponent<MeshRenderer>(); MeshFilter meshFilter = _cube.AddComponent<MeshFilter>(); Mesh mesh = meshFilter.mesh; //Create a 'Cube' mesh... //2) Define the cube's dimensions float length = 1f; float width = 1f; float height = 1f; //3) Define the co-ordinates of each Corner of the cube Vector3[] c = new Vector3[8]; c[0] = new Vector3(-length * .5f, -width * .5f, height * .5f); c[1] = new Vector3(length * .5f, -width * .5f, height * .5f); c[2] = new Vector3(length * .5f, -width * .5f, -height * .5f); c[3] = new Vector3(-length * .5f, -width * .5f, -height * .5f); c[4] = new Vector3(-length * .5f, width * .5f, height * .5f); c[5] = new Vector3(length * .5f, width * .5f, height * .5f); c[6] = new Vector3(length * .5f, width * .5f, -height * .5f); c[7] = new Vector3(-length * .5f, width * .5f, -height * .5f); //4) Define the vertices that the cube is composed of: //I have used 16 vertices (4 vertices per side). //This is because I want the vertices of each side to have separate normals. //(so the object renders light/shade correctly) Vector3[] vertices = new Vector3[] { c[0], c[1], c[2], c[3], // Bottom c[7], c[4], c[0], c[3], // Left c[4], c[5], c[1], c[0], // Front c[6], c[7], c[3], c[2], // Back c[5], c[6], c[2], c[1], // Right c[7], c[6], c[5], c[4] // Top }; //5) Define each vertex's Normal Vector3 up = Vector3.up; Vector3 down = Vector3.down; Vector3 forward = Vector3.forward; Vector3 back = Vector3.back; Vector3 left = Vector3.left; Vector3 right = Vector3.right; Vector3[] normals = new Vector3[] { down, down, down, down, // Bottom left, left, left, left, // Left forward, forward, forward, forward, // Front back, back, back, back, // Back right, right, right, right, // Right up, up, up, up // Top }; //6) Define each vertex's UV co-ordinates Vector2 uv00 = new Vector2(0f, 0f); Vector2 uv10 = new Vector2(1f, 0f); Vector2 uv01 = new Vector2(0f, 1f); Vector2 uv11 = new Vector2(1f, 1f); Vector2[] uvs = new Vector2[] { uv11, uv01, uv00, uv10, // Bottom uv11, uv01, uv00, uv10, // Left uv11, uv01, uv00, uv10, // Front uv11, uv01, uv00, uv10, // Back uv11, uv01, uv00, uv10, // Right uv11, uv01, uv00, uv10 // Top }; //7) Define the Polygons (triangles) that make up the our Mesh (cube) //IMPORTANT: Unity uses a 'Clockwise Winding Order' for determining front-facing polygons. //This means that a polygon's vertices must be defined in //a clockwise order (relative to the camera) in order to be rendered/visible. int[] triangles = new int[] { 3, 1, 0, 3, 2, 1, // Bottom 7, 5, 4, 7, 6, 5, // Left 11, 9, 8, 11, 10, 9, // Front 15, 13, 12, 15, 14, 13, // Back 19, 17, 16, 19, 18, 17, // Right 23, 21, 20, 23, 22, 21, // Top }; //8) Build the Mesh mesh.Clear(); mesh.vertices = vertices; mesh.triangles = triangles; mesh.normals = normals; mesh.uv = uvs; mesh.Optimize(); //mesh.RecalculateNormals(); _cube.transform.Translate(0f, 1f, -8f); //9) Give it a Material Material cubeMaterial = new Material(Shader.Find("Standard")); cubeMaterial.SetColor("_Color", new Color(0f, 0.7f, 0f)); //green main color _cube.GetComponent<Renderer>().material = cubeMaterial; } // Update is called once per frame void Update () { //Rotate the cube _cube.transform.Rotate(5f * Time.deltaTime, 15f * Time.deltaTime, 3f * Time.deltaTime); } } |