The Resource System

Resource types

The resource system has four different resource types/categories it can load.

  • Programs : Shader programs (vertex, geometry, fragment, tessellation, compute)

  • Textures : Textures of all different variations

  • Scenes: Wavefront, GLTF2 and STL scenes/objects

  • Data: A generic “lane” for everything else

Each of these resource categories have separate search directories, one or multiple loader classes and a ResourceDescription class we use to describe the resource we are loading with all its parameters.

Resource paths

Resources are loaded using relative paths. These paths are relative to one or multiple search directories we register using the resources module.

For simple usage were we have one or multiple resource directories with mixed resource types (programs, textures etc.) we can use the simplified version, register_dir().

from pathlib import Path
from moderngl_window import resources

# pathlib.Path (recommended)

# Strings and/or os.path

A resource finder system will scan through the registered directories in the order they were added loading the first resource found.

For more advanced usage were resources of different types are separated we can register resource type specific search directories:

This can be handy when dealing with larger quantities of files. These search directories are stored in the Settings instance and can for example be temporarily altered if needed. This means you can separate local and global resources in more complex situations. It could even be used to support themes by promoting a theme directory overriding global/default resources or some default theme directory.

Resource descriptions

Resource descriptions are basically just classes acting as bags of attributes describing the resource we are requesting. We have four standard classes.


from moderngl_window.meta import TextureDescription

# We are aiming to load wood.png horizontally flipped
# with generated mipmaps and high anisotropic filtering.

New resource description classes can be created by extending the base ResourceDescription class. This is not uncommon when for example making a new loader class.

Loading resources

Now that we know about the different resource categories, search paths and resource descriptions, we’re ready to actually load something.

Loading resources can in some situation be a bit verbose, but you can simplify by wrapping them in your own functions if needed. The WindowConfig class is already doing this and can be used as a reference.

from moderngl_window.resources import (
from moderngl_window.meta import (


# Load a 2D texture
texture = textures.load(TextureDescription(path='wood.png'))

# Load wood.png horizontally flipped with generated mipmaps and high anisotropic filtering.
textures.load(TextureDescription(path='wood.png', flip=True, mipmap=True, anisotropy=16.0))

# Load a texture array containing 10 vertically stacked tile textures
textures.load(TextureDescription(path='tiles.png', layers=10, mipmap=True, anisotrpy=8.0))


# Load a shader program in a single glsl file
program = programs.load(ProgramDescription(path='fun.glsl'))

# Load a shader program from multiple glsl files
program = programs.load(


# Load a GLTF2 scene
scene = scenes.load(SceneDescription(path="city.gltf'))

# Load a wavefront scene
scene = scenes.load(SceneDescription(path="earth.obj'))

# Load an STL file
scene = scenes.load(SceneDescription(path="apollo_landing_site_18.stl"))


# Load text file
text = data.load(DataDescription(path='notes.txt'))

# Load config file as a dict
config_dict = data.load(DataDescription(path='config.json'))

# Load binary data
data = data.load(DataDescription(path='data.bin', kind='binary))

For more information about supported parameters see the api documentation.