Detached Bind Mode

This example demonstrates how to sharing a skeleton across multiple skinned meshes with detached bind mode.

Note

To run this example, you need a model from the source repo’s example folder. If you are running this example from a local copy of the code (dev install) no further actions are needed. Otherwise, you may have to replace the path below to point to the location of the model.

import os
from pathlib import Path

try:
    # modify this line if your model is located elsewhere
    model_dir = Path(__file__).parents[1] / "data"
except NameError:
    # compatibility with sphinx-gallery
    model_dir = Path(os.getcwd()).parent / "data"

Once the path is set correctly, you can use the model as follows:

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

gltf_path = model_dir / "Michelle.glb"

canvas = WgpuCanvas(size=(640, 480), max_fps=-1, title="Skinnedmesh", vsync=False)

renderer = gfx.WgpuRenderer(canvas)
camera = gfx.PerspectiveCamera(75, 640 / 480, depth_range=(0.1, 1000))
camera.local.position = (0, 100, 200)
camera.look_at((0, 100, 0))
scene = gfx.Scene()

scene.add(gfx.AmbientLight(), gfx.DirectionalLight())


gltf = gfx.load_gltf(gltf_path, quiet=True)

# gfx.print_scene_graph(gltf.scene) # Uncomment to see the tree structure

# Group[Scene]
# - WorldObject[Character]
# - - SkinnedMesh[Ch03]
# - - Bone[mixamorig:Hips]
# - - - ...

model_obj = gltf.scene.children[0]
model_obj.local.scale = (1, 1, 1)
scene.add(model_obj)

skinnedmesh = model_obj.children[0]
skeleton = skinnedmesh.skeleton

skinnedmesh1 = gfx.SkinnedMesh(skinnedmesh.geometry, skinnedmesh.material)
skinnedmesh1.local.x = -80
skinnedmesh1.bind_mode = gfx.BindMode.detached
skinnedmesh1.bind(skeleton, np.eye(4))

scene.add(skinnedmesh1)

skinnedmesh2 = gfx.SkinnedMesh(skinnedmesh.geometry, skinnedmesh.material)
skinnedmesh2.local.x = 80
skinnedmesh2.bind_mode = gfx.BindMode.detached
skinnedmesh2.bind(skeleton, np.eye(4))

scene.add(skinnedmesh2)

skeleton_helper = gfx.SkeletonHelper(model_obj)
scene.add(skeleton_helper)

gfx.OrbitController(camera, register_events=renderer)

stats = gfx.Stats(viewport=renderer)

clock = gfx.Clock()
mixer = gfx.AnimationMixer()

action_clip = gltf.animations[0]
action = mixer.clip_action(action_clip)
action.play()


def animate():
    dt = clock.get_delta()
    mixer.update(dt)

    skeleton.update()
    skeleton_helper.update()

    with stats:
        renderer.render(scene, camera, flush=False)
    stats.render()
    canvas.request_draw()


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