ArrayMeshの使用¶
This tutorial will present the basics of using an ArrayMesh.
そのためには、関数 add_surface_from_arrays() を使用します。これは最大4つのパラメーターを取ります。最初の2つは必須ですが、残りの2つはオプションです。
The first parameter is the PrimitiveType, an OpenGL concept that instructs the GPU
how to arrange the primitive based on the vertices given, i.e. whether they represent triangles,
lines, points, etc. See Mesh.PrimitiveType for the options available.
The second parameter, arrays, is the actual Array that stores the mesh information. The array is a
normal Godot array that is constructed with empty brackets []. It stores a Pool**Array
(e.g. PoolVector3Array, PoolIntArray, etc.) for each type of information that will be used to build the surface.
The possible elements of arrays are listed below, together with the position they must have within arrays.
See also Mesh.ArrayType.
インデックス |
Mesh.ArrayType Enum |
Array type |
|---|---|---|
0 |
|
|
1 |
|
|
2 |
|
PoolRealArray of groups of 4 floats. First 3 floats determine the tangent, and the last the binormal direction as -1 or 1. |
3 |
|
|
4 |
|
|
5 |
|
|
6 |
|
PoolRealArray of groups of 4 floats or PoolIntArray of groups of 4 ints. Each group lists indexes of 4 bones that affects a given vertex. |
7 |
|
PoolRealArray of groups of 4 floats. Each float lists the amount of weight an determined bone on |
8 |
|
The array of vertices (at index 0) is always required. The index array is optional and will only be used if included. We won't use it in this tutorial.
All the other arrays carry information about the vertices. They are also optional and will only be used if included. Some of these arrays (e.g. ARRAY_COLOR)
use one entry per vertex to provide extra information about vertices. They must have the same size as the vertex array. Other arrays (e.g. ARRAY_TANGENT) use
four entries to describe a single vertex. These must be exactly four times larger than the vertex array.
For normal usage, the last two parameters in add_surface_from_arrays() are typically left empty.
ArrayMesh¶
In the editor, create a MeshInstance and add an ArrayMesh to it in the Inspector. Normally, adding an ArrayMesh in the editor is not useful, but in this case it allows us to access the ArrayMesh from code without creating one.
次に、MeshInstanceにスクリプトを追加します。
_ready() 下に、新しい配列を作成します。
var surface_array = []
This will be the array that we keep our surface information in - it will hold
all the arrays of data that the surface needs. Godot will expect it to be of
size Mesh.ARRAY_MAX, so resize it accordingly.
var surface_array = []
surface_array.resize(Mesh.ARRAY_MAX)
次に、使用する各データ型の配列を作成します。
var verts = PoolVector3Array()
var uvs = PoolVector2Array()
var normals = PoolVector3Array()
var indices = PoolIntArray()
データ配列にジオメトリを入力したら、各配列を surface_array に追加し、メッシュにコミットすることでメッシュを作成できます。
surface_array[Mesh.ARRAY_VERTEX] = verts
surface_array[Mesh.ARRAY_TEX_UV] = uvs
surface_array[Mesh.ARRAY_NORMAL] = normals
surface_array[Mesh.ARRAY_INDEX] = indices
mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, surface_array) # No blendshapes or compression used.
注釈
この例では、Mesh.PRIMITIVE_TRIANGLES を使用しましたが、メッシュから利用可能な任意のプリミティブタイプを使用できます。
Put together, the full code looks like:
extends MeshInstance
func _ready():
var surface_array= []
surface_array.resize(Mesh.ARRAY_MAX)
# PoolVector**Arrays for mesh construction.
var verts = PoolVector3Array()
var uvs = PoolVector2Array()
var normals = PoolVector3Array()
var indices = PoolIntArray()
#######################################
## Insert code here to generate mesh ##
#######################################
# Assign arrays to mesh array.
surface_array[Mesh.ARRAY_VERTEX] = verts
surface_array[Mesh.ARRAY_TEX_UV] = uvs
surface_array[Mesh.ARRAY_NORMAL] = normals
surface_array[Mesh.ARRAY_INDEX] = indices
# Create mesh surface from mesh array.
mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, surface_array) # No blendshapes or compression used.
The code that goes in the middle can be whatever you want. Below we will present some example code for generating a sphere.
ジオメトリの生成¶
球体を生成するためのサンプルコードを次に示します。コードはGDScriptで表示されますが、コードを生成する方法についてGodot固有のものはありません。この実装は、ArrayMeshとは特に関係がなく、球体を生成するための一般的なアプローチです。理解に問題がある場合、または手続き型ジオメトリ全般について詳しく知りたい場合は、オンラインで見つけたチュートリアルを使用できます。
extends MeshInstance
var rings = 50
var radial_segments = 50
var height = 1
var radius = 1
func _ready():
# Insert setting up the PoolVector**Arrays here.
# Vertex indices.
var thisrow = 0
var prevrow = 0
var point = 0
# Loop over rings.
for i in range(rings + 1):
var v = float(i) / rings
var w = sin(PI * v)
var y = cos(PI * v)
# Loop over segments in ring.
for j in range(radial_segments):
var u = float(j) / radial_segments
var x = sin(u * PI * 2.0)
var z = cos(u * PI * 2.0)
var vert = Vector3(x * radius * w, y, z * radius * w)
verts.append(vert)
normals.append(vert.normalized())
uvs.append(Vector2(u, v))
point += 1
# Create triangles in ring using indices.
if i > 0 and j > 0:
indices.append(prevrow + j - 1)
indices.append(prevrow + j)
indices.append(thisrow + j - 1)
indices.append(prevrow + j)
indices.append(thisrow + j)
indices.append(thisrow + j - 1)
if i > 0:
indices.append(prevrow + radial_segments - 1)
indices.append(prevrow)
indices.append(thisrow + radial_segments - 1)
indices.append(prevrow)
indices.append(prevrow + radial_segments)
indices.append(thisrow + radial_segments - 1)
prevrow = thisrow
thisrow = point
# Insert committing to the ArrayMesh here.
保存¶
Finally, we can use the ResourceSaver class to save the ArrayMesh. This is useful when you want to generate a mesh and then use it later without having to re-generate it.
# Saves mesh to a .tres file with compression enabled.
ResourceSaver.save("res://sphere.tres", mesh, ResourceSaver.FLAG_COMPRESS)