Godot Version
4.5
Question
I am currently working on a hexagonal tile that is able to change height by specific increments when given a number. The issue I am having is that I am not able to map the UV coordinates of the vertices so that the texture for the sides uses the same texture for each segment.
I want to use the CylinderMesh to create the tile. However, the CylinderMesh does not have built-in methods for adjusting the UVs of the vertices. To that end, I create an ArrayMesh based on the desired CylinderMesh shape and then adjust the UVs using MeshDataTool.
@tool
class_name ScalingHexMesh
extends MeshInstance3D
## Enables a MeshInstance3D to be adjustable by outside factors.
## The UV coordinates for the top vertices of the mesh.
const UV_TOP: PackedVector2Array = [
Vector2(0.98, 0.39),
Vector2(0.74, 0.01),
Vector2(0.26, 0.01),
Vector2(0.02, 0.39),
Vector2(0.26, 0.76),
Vector2(0.74, 0.76),
Vector2(0.98, 0.39),
Vector2(0.5, 0.39), # center vertex
]
## The UV coordinates for the side of the mesh. Each side segment uses the same
## texture (or is at least supposed to).
const UV_SIDE: PackedVector2Array = [
Vector2(0.26, 0.79), # top left
Vector2(0.72, 0.98), # bottom right
Vector2(0.26, 0.98), # bottom left
Vector2(0.72, 0.79), # top right
]
## The mesh used to represent a hex tile.
var _hex_mesh: ArrayMesh:
get:
return mesh as ArrayMesh
## Updates the shape mesh so that it reflects the current height.
func _update_tile_shape_height(height: int) -> void:
# Move the shape so that the bottom is always at -0.25
mesh = _create_base_mesh(height)
var y_translate: float = (HexUtil.HEX_TILE_UNIT_HEIGHT / 2) * (height - 1)
set_position(Vector3(0.0, y_translate, 0.0))
_update_uvs()
## Update the UV map of the mesh to align with the base texture:
## res://art/hex_base_texture.png
func _update_uvs() -> void:
var mesh_data := MeshDataTool.new()
mesh_data.create_from_surface(_hex_mesh, 0)
var vertex_count: int = mesh_data.get_vertex_count()
## Set the UVs for the top cap of the mesh.
for i: int in UV_TOP.size():
mesh_data.set_vertex_uv(vertex_count - i - 1, UV_TOP[i])
## Set the UVs for the side segments of the mesh.
var even_row: int
var even_vertex: int
for i: int in vertex_count - UV_TOP.size():
even_row = i % 2
even_vertex = i % 7 % 2
mesh_data.set_vertex_uv(i, UV_SIDE[even_row * 2 + even_vertex])
mesh_data.commit_to_surface(_hex_mesh)
## Creates an array mesh for the hex tile of the specified height.
func _create_base_mesh(height: int) -> ArrayMesh:
var cylinder_mesh := CylinderMesh.new()
cylinder_mesh.top_radius = HexUtil.HEX_TILE_RADIUS
cylinder_mesh.bottom_radius = HexUtil.HEX_TILE_RADIUS
cylinder_mesh.height = HexUtil.HEX_TILE_UNIT_HEIGHT * (1 + height)
cylinder_mesh.radial_segments = 6
cylinder_mesh.rings = height
cylinder_mesh.cap_bottom = false
var array_mesh := ArrayMesh.new()
array_mesh.add_surface_from_arrays(
Mesh.PRIMITIVE_TRIANGLES,
cylinder_mesh.get_mesh_arrays()
)
return array_mesh
## Triggers an update to the shape height.
func _on_HeightSource_height_changed(height: int) -> void:
_update_tile_shape_height(height)
I am using this image as the texture. It will serve as a baseline for all other textures I will be making for the tiles.
The logic for creating the ArrayMesh works, but there is a problem with the UVs. The top UVs are good, but the UVs for the side vertices are not able to be set in such a way to allow for the side texture to be in the same orientation across all segments.
I’ve created a variant of the hex tile using some Blender models that I made, which has the desired texture pattern.
What I want to know is if there is a way to set up the UVs of a CylinderMesh so that the texture looks like the above.
