Использование ArrayMesh

This tutorial will present the basics of using an ArrayMesh.

Для этого мы будем использовать функцию add_surface_from_arrays(), которая принимает до четырех параметров. Первые два являются обязательными, а вторые два - необязательными.

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.

Индекс	Mesh.ArrayType Enum	Array type
0	ARRAY_VERTEX	PoolVector3Array or PoolVector2Array
1	ARRAY_NORMAL	PoolVector3Array
2	ARRAY_TANGENT	PoolRealArray of groups of 4 floats. First 3 floats determine the tangent, and the last the binormal direction as -1 or 1.
3	ARRAY_COLOR	PoolColorArray
4	ARRAY_TEX_UV	PoolVector2Array or PoolVector3Array
5	ARRAY_TEX_UV2	PoolVector2Array or PoolVector3Array
6	ARRAY_BONES	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	ARRAY_WEIGHTS	PoolRealArray of groups of 4 floats. Each float lists the amount of weight an determined bone on ARRAY_BONES has on a given vertex.
8	ARRAY_INDEX	PoolIntArray

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.

Затем добавьте скрипт в MeshInstance.

Ниже _ready() создайте новый массив.

GDScript

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.

GDScript

var surface_array = []
surface_array.resize(Mesh.ARRAY_MAX)

Затем создайте массивы для каждого типа данных, который вы будете использовать.

GDScript

var verts = PoolVector3Array()
var uvs = PoolVector2Array()
var normals = PoolVector3Array()
var indices = PoolIntArray()

После того, как вы заполнили свои массивы данных своей геометрией, вы можете создать сетку, добавив каждый массив в surface_array, а затем зафиксировав его в сетке.

GDScript

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.

Примечание

В этом примере мы использовали Mesh.PRIMITIVE_TRIANGLES, но вы можете использовать любой примитивный тип, доступный из сетки.

Put together, the full code looks like:

GDScript

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.

Generating geometry

Здесь приведен пример кода для генерации сферы. Хотя код представлен на GDScript, в подходе к генерации сферы нет ничего специфичного для Godot. Эта реализация не имеет ничего общего с ArrayMeshes и является просто общим подходом к генерации сферы. Если у вас возникли трудности с пониманием или вы хотите узнать больше о процедурной геометрии в целом, вы можете воспользоваться любым учебником, который найдете в Интернете.

GDScript

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.

Сохранение

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.

GDScript

# Saves mesh to a .tres file with compression enabled.
ResourceSaver.save("res://sphere.tres", mesh, ResourceSaver.FLAG_COMPRESS)