Atlas Textures in 3D

[grand zinc]

I am trying to put an atlas texture onto a MeshInstance3D. The only issue is, is when I try to create a region for the atlas, it doesn't really pay attention to it. The goal is to be able to grab anywhere on the atlas dynamically and put it onto a mesh instance.

Current work I concepted

extends Node3D

@onready var meshparent = $meshparent
@onready var RockMesh = $RockMesh

func _ready():
apply_data()

func apply_data():
if Rockregistry.current_rocks:
var temp = Rockregistry.current_rocks.pick_random()
var data = temp.duplicate()

    var inst = load(data.mesh_path).instantiate()
    meshparent.add_child(inst)
    
    var atlas = AtlasTexture.new()
    atlas.atlas = data.atlas_texture
    var rect = Rect2(data.offset.x, data.offset.y, 16, 16)
    atlas.set_region(rect)
    
    var mat = StandardMaterial3D.new()
    mat.albedo_texture = atlas
    mat.texture_filter = BaseMaterial3D.TEXTURE_FILTER_NEAREST
    
    for i in meshparent.get_children():
        for j in i.get_children():
            if j is MeshInstance3D:
                j.material_override = mat

[bronze condor]

AtlasTexture only works for 2D. for 3D you would just set your UVs accordingly in your mesh.

you could also use Texture2DArray as an option

[grand zinc]

Literally just did that and it worked! was really hoping for atlas textures to translate though.

[bronze condor]

It’s a tricky one to make work with random 3D meshes. I wouldn’t expect to see that supported anytime soon so stick with what you have working now!

[vernal moss]

It's surprisingly easy to make it work with the standard shader with a few tweaks.

1. Calculate the pixel to UV ratio.
2. Calculate number of pixels in selected region.
3. Use this to calculate the new UV ratio.
4. Multiply existing UVs by this ratio (wrap any exceeding 1.0)
   5.. Offset UVs by using region start point and pixel to UV ratio calculated earlier.

[full granite]

what mesh type did you try to put on? It would probably make most sense on a Quad. Or Sprite3D if you want it to be shown as a 2D billboard in a 3D scene