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Usando o ArrayMesh

This tutorial will present the basics of using an ArrayMesh.

To do so, we will use the function add_surface_from_arrays(), which takes up to five parameters. The first two are required, while the last three are optional.

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 Packed**Array (e.g. PackedVector3Array, PackedInt32Array, etc.) for each type of information that will be used to build the surface.

Common elements of arrays are listed below, together with the position they must have within arrays. See Mesh.ArrayType for a full list.

Índice

Mesh.ArrayType Enum

Tipo de matriz

0

ARRAY_VERTEX

PackedVector3Array or PackedVector2Array

1

ARRAY_NORMAL

PackedVector3Array

2

ARRAY_TANGENT

PackedFloat32Array or PackedFloat64Array of groups of 4 floats. The first 3 floats determine the tangent, and the last float the binormal direction as -1 or 1.

3

ARRAY_COLOR

PackedColorArray

4

ARRAY_TEX_UV

PackedVector2Array or PackedVector3Array

5

ARRAY_TEX_UV2

PackedVector2Array or PackedVector3Array

10

ARRAY_BONES

PackedFloat32Array of groups of 4 floats or PackedInt32Array of groups of 4 ints. Each group lists indexes of 4 bones that affects a given vertex.

11

ARRAY_WEIGHTS

PackedFloat32Array or PackedFloat64Array of groups of 4 floats. Each float lists the amount of weight the corresponding bone in ARRAY_BONES has on a given vertex.

12

ARRAY_INDEX

PackedInt32Array

In most cases when creating a mesh, we define it by its vertex positions. So usually, the array of vertices (at index 0) is required, while the index array (at index 12) is optional and will only be used if included. It is also possible to create a mesh with only the index array and no vertex array, but that's beyond the scope of this tutorial. In fact, we won't use the index array at all.

All the other arrays carry information about the vertices. They are 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 three parameters in add_surface_from_arrays() are typically left empty.

Setting up the ArrayMesh

In the editor, create a MeshInstance3D 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.

Next, add a script to the MeshInstance3D.

Em ''_ready()'', crie uma nova Array.

var surface_array = []

Esta será a matriz na qual manteremos nossas informações de superfície - ela conterá todas as matrizes de dados que a superfície necessita. Godot espera que ela seja do tamanho Mesh.ARRAY_MAX, portanto, redimensione-a de acordo.

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

Em seguida, crie as matrizes para cada tipo de dado que você usará.

var verts = PackedVector3Array()
var uvs = PackedVector2Array()
var normals = PackedVector3Array()
var indices = PackedInt32Array()

Uma vez que você tenha preenchido suas matrizes de dados com sua geometria, você pode criar uma malha adicionando cada matriz a surface_array e, em seguida, comitando para a malha.

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

# No blendshapes, lods, or compression used.
mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, surface_array)

Nota

Neste exemplo, utilizamos Mesh.PRIMITIVE_TRIANGLES, mas você pode utilizar qualquer tipo primitivo disponível na malha.

Juntos, o código completo se parece com:

extends MeshInstance3D

func _ready():
    var surface_array = []
    surface_array.resize(Mesh.ARRAY_MAX)

    # PackedVector**Arrays for mesh construction.
    var verts = PackedVector3Array()
    var uvs = PackedVector2Array()
    var normals = PackedVector3Array()
    var indices = PackedInt32Array()

    #######################################
    ## Insert code here to generate mesh ##
    #######################################

    # Assign arrays to surface 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.
    # No blendshapes, lods, or compression used.
    mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, surface_array)

O código que vai no meio pode ser o que você quiser. A seguir apresentaremos um exemplo de código para gerar uma esfera.

Gerando geometria

Aqui está uma amostra de código para gerar uma esfera. Embora o código seja apresentado no GDScript, não há nada de específico do Godot sobre a abordagem para gerá-lo. Esta implementação não tem nada em particular a ver com ArrayMeshes e é apenas uma abordagem genérica para a geração de uma esfera. Se você estiver tendo problemas para compreendê-la ou quiser aprender mais sobre a geometria de procedimentos em geral, você pode usar qualquer tutorial que encontrar on-line.

extends MeshInstance3D

var rings = 50
var radial_segments = 50
var radius = 1

func _ready():

    # Insert setting up the PackedVector**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 * radius, 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.

Salvando

Finalmente, podemos usar a classe :ref:'ResourceSaver<class_resourcesaver>' para salvar a ArrayMesh. Isso é útil quando você deseja gerar uma malha e, em seguida, usá-la mais tarde sem ter que gerá-la novamente.

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