Sponza Scene

This example shows how to load the Sponza scene. To run it, you have to have access to the sponza demo scene, which you can get using:

git clone https://github.com/KhronosGroup/glTF-Sample-Models

The current implementation assumes that you cloned that repo in this directory, or any of its parent directories.

from pathlib import Path

from wgpu.gui.auto import WgpuCanvas, run
import pygfx as gfx


# Note: __file__ is the relative path from cwd when called as "__main__". Hence,
# we need to resolve() to allow calling from anywhere in the repo.
# Note: if we want a better way to find that repo, let's use an env var ...
path = Path(__file__).resolve().parent
while True:
    gltf_samples_repo = path / "glTF-Sample-Models"
    if gltf_samples_repo.is_dir():
        break
    try:
        path = path.parents[0]
    except IndexError:
        raise RuntimeError("Could not find 'glTF-Sample-Models' directory.")


gltf_path = gltf_samples_repo / "2.0" / "Sponza" / "glTF" / "Sponza.gltf"

# Init
canvas = WgpuCanvas(size=(640, 480), title="gltf viewer")
renderer = gfx.renderers.WgpuRenderer(canvas)
scene = gfx.Scene()

# Create camera and controller
camera = gfx.PerspectiveCamera(45, 640 / 480)
camera.local.position = -10, 1.8, -0.3
camera.show_pos((0, 0, 0))
controller = gfx.FlyController(camera, register_events=renderer, speed=2)


def configure(obj):
    obj.receive_shadow = True
    obj.cast_shadow = True


# Load scene
scene.add(*gfx.load_mesh(gltf_path.as_posix()))
scene.traverse(configure)

# Add ambient light
scene.add(gfx.AmbientLight(intensity=0.1))

# Add the sun, midday direction
sunlight = gfx.DirectionalLight()
sunlight.local.position = -14.5, 31, 4.5
sunlight.target.local.position = 5.3, -1.4, -2.5
sunlight.cast_shadow = True
sunlight.shadow.camera.depth_range = (0, 250)
sunlight.shadow.camera.update_projection_matrix()
scene.add(sunlight)

# Add torches
for pos in [
    [-5.0, 1.12, -1.75],
    [-5.0, 1.12, 1.15],
    [3.8, 1.12, -1.75],
    [3.8, 1.12, 1.15],
]:
    torch = gfx.PointLight("#ff7700", decay=2.5)
    torch.local.position = pos
    torch.cast_shadow = True
    torch.shadow.camera.depth_range = (0.01, 200)
    torch.shadow.camera.update_projection_matrix()
    torch.shadow.cull_mode = "none"
    torch.shadow.bias = 0.001
    # torch.add(gfx.PointLightHelper(size=0.01))
    scene.add(torch)


stats = gfx.Stats(viewport=renderer)


def animate():
    with stats:
        renderer.render(scene, camera, flush=False)
    stats.render()


if __name__ == "__main__":
    renderer.request_draw(animate)
    run()