Nonexistent function 'surface_set_material' in base 'MeshInstance3D'

SlyPhi

Hi. New to Godot and trying to re-visit something I started years ago. Getting stuck on an error that I can find no explanation for. This code should display an nth frequency truncated icosahedron but keeps throwing errors. No idea how to fix this as no idea what the error message means.

Any help appreciated...


extends MeshInstance3D


func _ready():
	var n = 3
	var phi = (1.0 + sqrt(5.0)) / 2.0  
	
# Define the 12 vertices of a regular icosahedron
var icosahedron_vertices = [
	Vector3(1, phi, 0),
	Vector3(-1, phi, 0),
	Vector3(1, -phi, 0),
	Vector3(-1, -phi, 0),
	
	Vector3(0, 1, phi),
	Vector3(0, -1, phi),
	Vector3(0, 1, -phi),
	Vector3(0, -1, -phi),
	
	Vector3(phi, 0, 1),
	Vector3(-phi, 0, 1),
	Vector3(phi, 0, -1),
	Vector3(-phi, 0, -1)
]

# Define the indices to connect vertices and form faces
var face_indices = [
	0, 1, 4, 0, 4, 8, 0, 8, 5, 0, 5, 2, 0, 2, 1,
	3, 1, 2, 3, 2, 7, 3, 7, 11, 3, 11, 9, 3, 9, 1,
	6, 10, 11, 6, 11, 7, 6, 7, 2, 6, 2, 5, 6, 5, 10,
	4, 10, 5, 4, 8, 10, 4, 9, 11, 4, 11, 8, 4, 1, 9,
	10, 8, 11, 9, 1, 10, 5, 8, 11, 2, 7, 9, 7, 2, 6
]

# Calculate the vertices of the nth-frequency truncated icosahedron
var truncated_icosahedron_vertices = []
for vertex in icosahedron_vertices:
	var length = vertex.length()
	var new_vertex = vertex.normalized() * (length + n)
	truncated_icosahedron_vertices.append(new_vertex)

# Create an ArrayMesh to store the faces
var array_mesh = ArrayMesh.new()

# Convert vertices to an array
var vertices_array = []
for vertex in truncated_icosahedron_vertices:
	vertices_array += [vertex.x, vertex.y, vertex.z]

# Convert indices to an array
var indices_array = []
for index in face_indices:
	indices_array.append(index)

# Add arrays to the ArrayMesh
array_mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, [vertices_array, indices_array])

# Load the "colr" material resource
var colr_material = load("res://colr.tres")

# Create and display the faces of the truncated icosahedron
for i in range(0, len(face_indices), 3):
	var triangle_instance = MeshInstance3D.new()
	triangle_instance.mesh = array_mesh
	triangle_instance.surface_set_material(0, colr_material)
	triangle_instance.surface_set_primitive_type(0, Mesh.PRIMITIVE_TRIANGLES)
	triangle_instance.surface_set_array_index(0, i)
	add_child(triangle_instance)

xyz

SlyPhi surface_set_material() is the method of Mesh, not MeshInstance3D.

SlyPhi

xyz I changed this to Mesh but it didn't work 🙁

AwesomeUnicorn3

Have you tried:
set_surface_override_material ( int surface, Material material )

xyz

SlyPhi Changed what to Mesh, and in what way it didn't work?

award

@SlyPhi

Can you post the error messages, starting from the first one?

SlyPhi

Ok I've got code that doesn't throw error messages but also doesn't display anything 🙁

extends MeshInstance3D

func _ready():
	var n = 3
	var phi = (1.0 + sqrt(5.0)) / 2.0  
	
# Define the 12 vertices of a regular icosahedron
var icosahedron_vertices = [
	Vector3(1, phi, 0),
	Vector3(-1, phi, 0),
	Vector3(1, -phi, 0),
	Vector3(-1, -phi, 0),
	
	Vector3(0, 1, phi),
	Vector3(0, -1, phi),
	Vector3(0, 1, -phi),
	Vector3(0, -1, -phi),
	
	Vector3(phi, 0, 1),
	Vector3(-phi, 0, 1),
	Vector3(phi, 0, -1),
	Vector3(-phi, 0, -1)
]

# Define the indices to connect vertices and form faces
var face_indices = [
	0, 1, 4, 0, 4, 8, 0, 8, 5, 0, 5, 2, 0, 2, 1,
	3, 1, 2, 3, 2, 7, 3, 7, 11, 3, 11, 9, 3, 9, 1,
	6, 10, 11, 6, 11, 7, 6, 7, 2, 6, 2, 5, 6, 5, 10,
	4, 10, 5, 4, 8, 10, 4, 9, 11, 4, 11, 8, 4, 1, 9,
	10, 8, 11, 9, 1, 10, 5, 8, 11, 2, 7, 9, 7, 2, 6
]

# Calculate the vertices of the nth-frequency truncated icosahedron
var truncated_icosahedron_vertices = []
for vertex in icosahedron_vertices:
	var length = vertex.length()
	var new_vertex = vertex.normalized() * (length + n)
	truncated_icosahedron_vertices.append(new_vertex)

# Create and assign the mesh for the truncated icosahedron
var array_mesh = ArrayMesh.new()

var vertex_array = []
for vertex in truncated_icosahedron_vertices:
	vertex_array += [vertex.x, vertex.y, vertex.z]

var indices = []
for i in range(len(truncated_icosahedron_vertices)):
	indices.append(i)

var arrays = []
arrays.append(Mesh.ARRAY_VERTEX)
arrays.append(vertex_array)
arrays.append(Mesh.ARRAY_INDEX)
arrays.append(indices)

array_mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, arrays)

self.mesh = array_mesh  # Set the mesh for this MeshInstance3D


self.material_override = load("res://colr.tres")

SlyPhi

OK I've made a lot of progress. I have code that displays an nth frequency icosahedron.

The problem now is I am unable to individually colour each face. No matter what I do it always just displays in a single colour.

I'm just trying to apply 2 colours at the moment held in 2 materials called colr1 and colr2. Nothing I do works.

Any help appreciated

@tool
extends MeshInstance3D

@export var frequency : int = 0
@export var update : bool = false
@export var radius : float = 6.0 
var phi = (1.0 + sqrt(5.0)) / 2.0
var vertices_data := [
	0, 1, phi,
	0, -1, phi,
	0, 1, -phi,
	0, -1, -phi,
	1, phi, 0,
	-1, phi, 0,
	1, -phi, 0,
	-1, -phi, 0,
	phi, 0, 1,
	-phi, 0, 1,
	phi, 0, -1,
	-phi, 0, -1
]

var indices_data := [
	6, 3, 7,
	3, 6, 10,
	2, 3, 10,
	10, 4, 2,
	3, 2, 11,
	11, 7, 3,
	2, 4, 5,
	2, 5, 11,
	10, 8, 4,
	10, 6, 8,
	8, 6, 1,
	6, 7, 1,
	1, 0, 8,
	8, 0, 4,
	4, 0, 5,
	9, 5, 0,
	9, 0, 1,
	9, 1, 7,
	9, 7, 11,
	9, 11, 5
]

# Add materials for each face
@export var materials : Array = []

func _ready():
	# Load materials and add them to the materials array
	var material1 = load("res://colr1.tres")
	var material2 = load("res://colr2.tres")
	materials.append(material1)
	materials.append(material2)
	gen_mesh()

func gen_mesh():
	var array_mesh = ArrayMesh.new()

var vertices := PackedVector3Array()
var indices := PackedInt32Array()

# Define the 12 vertices of an icosahedron
for j in range(12):
	var vertex = Vector3(vertices_data[j * 3], vertices_data[j * 3 + 1], vertices_data[j * 3 + 2])
	vertices.append(vertex.normalized() * radius) # Scale by the desired radius

# Define the initial triangle indices
for j in range(indices_data.size()):
	indices.append(indices_data[j])

# Subdivide the icosahedron recursively
for j in range(frequency):
	subdivide(vertices, indices)

var arrays = []
arrays.resize(Mesh.ARRAY_MAX)
arrays[Mesh.ARRAY_VERTEX] = vertices
arrays[Mesh.ARRAY_INDEX] = indices

array_mesh.add_surface_from_arrays(Mesh.PRIMITIVE_TRIANGLES, arrays)
array_mesh.surface_set_material(0, materials[0])
array_mesh.surface_set_material(1, materials[1])

mesh = array_mesh

func subdivide(vertices, indices):
	var new_indices := PackedInt32Array()

for i in range(indices.size() / 3):
	var i1 = indices[i * 3]
	var i2 = indices[i * 3 + 1]
	var i3 = indices[i * 3 + 2]

	var v1 = vertices[i1]
	var v2 = vertices[i2]
	var v3 = vertices[i3]

	var v12 = (v1 + v2).normalized()
	var v23 = (v2 + v3).normalized()
	var v31 = (v3 + v1).normalized()

	var i12 = vertices.size()
	var i23 = i12 + 1
	var i31 = i23 + 1

	vertices.append(v12 * radius) # Scale by the desired radius
	vertices.append(v23 * radius) # Scale by the desired radius
	vertices.append(v31 * radius) # Scale by the desired radius

	new_indices.append(i1)
	new_indices.append(i12)
	new_indices.append(i31)

	new_indices.append(i2)
	new_indices.append(i23)
	new_indices.append(i12)

	new_indices.append(i3)
	new_indices.append(i31)
	new_indices.append(i23)

	new_indices.append(i12)
	new_indices.append(i23)
	new_indices.append(i31)

indices.clear()
indices.append_array(new_indices)

func _process(_delta):
	if update:
		gen_mesh()
		update = false

xyz

SlyPhi You should use vertex colors if you want to color each individual face.