Depth Overlay 1

Example (and test) for behavior of the depth buffer w.r.t. overlays, implemented by multiple render calls. The overlay should always be on top.

import numpy as np
from wgpu.gui.auto import WgpuCanvas, run
import pygfx as gfx
import pylinalg as la


# Create a canvas and renderer

canvas = WgpuCanvas(size=(500, 300))
renderer = gfx.renderers.WgpuRenderer(canvas)

# Compose a scene with a 3D cube at the origin

scene1 = gfx.Scene()

cube1 = gfx.Mesh(
    gfx.box_geometry(),
    gfx.MeshPhongMaterial(color="#ff0"),
)
rot = la.quat_from_euler((0.2, 0.3), order="XY")
cube1.local.rotation = la.quat_mul(rot, cube1.local.rotation)
scene1.add(cube1)

# Compose a scene with a 2D square at the origin, in the xy plane

scene2 = gfx.Scene()

positions = np.array(
    [
        [-1, -1, 0.0],
        [-1, +1, 0.0],
        [+1, +1, 0.0],
        [+1, -1, 0.0],
        [-1, -1, 0.0],
        [+1, +1, 0.0],
    ],
    np.float32,
)
line2 = gfx.Line(
    gfx.Geometry(positions=positions * 0.5),
    gfx.LineMaterial(thickness=5.0, color="#f0f"),
)
scene2.add(line2)

# Camera

camera = gfx.OrthographicCamera(2, 2)
scene1.add(camera.add(gfx.DirectionalLight()))


def draw():
    renderer.render(scene1, camera, flush=False)
    renderer.render(scene2, camera, flush=False)
    renderer.flush()


canvas.request_draw(draw)

if __name__ == "__main__":
    print(__doc__)
    run()