.. DO NOT EDIT.
.. THIS FILE WAS AUTOMATICALLY GENERATED BY SPHINX-GALLERY.
.. TO MAKE CHANGES, EDIT THE SOURCE PYTHON FILE:
.. "_gallery/feature_demo/skinned_mesh.py"
.. LINE NUMBERS ARE GIVEN BELOW.

.. only:: html

    .. note::
        :class: sphx-glr-download-link-note

        :ref:`Go to the end <sphx_glr_download__gallery_feature_demo_skinned_mesh.py>`
        to download the full example code.

.. rst-class:: sphx-glr-example-title

.. _sphx_glr__gallery_feature_demo_skinned_mesh.py:


Skinned Mesh
============

This example shows the rendering of a skinned mesh with a skeleton and bones.

.. GENERATED FROM PYTHON SOURCE LINES 7-121



.. image-sg:: /_gallery/feature_demo/images/sphx_glr_skinned_mesh_001.webp
   :alt: skinned mesh
   :srcset: /_gallery/feature_demo/images/sphx_glr_skinned_mesh_001.webp
   :class: sphx-glr-single-img





.. code-block:: Python



    import math
    import time
    import numpy as np
    import pygfx as gfx
    import pylinalg as la
    from rendercanvas.auto import RenderCanvas, loop


    def create_geometry(sizing):
        geometry = gfx.cylinder_geometry(
            5, 5, sizing["height"], 8, sizing["segment_height"], open_ended=True
        )
        positions = geometry.positions

        skin_indices = np.zeros((positions.nitems, 4), dtype=np.uint32)
        skin_weights = np.zeros((positions.nitems, 4), dtype=np.float32)

        for i in range(positions.nitems):
            vertex = positions.data[i]
            z = vertex[2] + sizing["half_height"]
            skin_index = z // sizing["segment_height"]
            skin_weight = (z % sizing["segment_height"]) / sizing["segment_height"]

            skin_indices[i] = [skin_index, skin_index + 1, 0, 0]
            skin_weights[i] = [1 - skin_weight, skin_weight, 0, 0]

        geometry.skin_indices = gfx.Buffer(skin_indices)
        geometry.skin_weights = gfx.Buffer(skin_weights)

        return geometry


    def create_bones(sizing):
        bones = []
        prev_bone = gfx.Bone()
        bones.append(prev_bone)

        prev_bone.local.position = (0, 0, -sizing["half_height"])

        for _ in range(sizing["segment_count"]):
            bone = gfx.Bone()
            bone.local.position = (0, 0, sizing["segment_height"])
            bones.append(bone)

            prev_bone.add(bone)
            prev_bone = bone

        return bones


    def create_mesh(geometry, bones):
        material = gfx.MeshNormalMaterial()

        material.flat_shading = True

        mesh = gfx.SkinnedMesh(geometry, material)
        skeleton = gfx.Skeleton(bones)

        mesh.add(bones[0])
        mesh.bind(skeleton)

        mesh.local.rotation = la.quat_from_euler((-math.pi / 2, 0, 0))
        return mesh


    segment_height = 8
    segment_count = 4
    height = segment_height * segment_count
    half_height = height * 0.5

    sizing = {
        "segment_height": segment_height,
        "segment_count": segment_count,
        "height": height,
        "half_height": half_height,
    }

    canvas = RenderCanvas(size=(640, 480), max_fps=60, title="Skinnedmesh")

    renderer = gfx.WgpuRenderer(canvas)

    camera = gfx.PerspectiveCamera(75, 640 / 480, depth_range=(0.1, 200))
    camera.local.position = (0, 30, 30)
    camera.look_at((0, 0, 0))

    scene = gfx.Scene()

    geometry = create_geometry(sizing)
    bones = create_bones(sizing)
    mesh = create_mesh(geometry, bones)

    scene.add(mesh)

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

    gfx.OrbitController(camera, register_events=renderer)


    def animate():
        t = time.time()
        for bone in mesh.skeleton.bones:
            rotation_y = math.sin(t) * 2 / len(mesh.skeleton.bones)
            bone.local.rotation = la.quat_from_euler((0, rotation_y, 0))

        renderer.render(scene, camera)
        canvas.request_draw()


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


.. rst-class:: sphx-glr-timing

   **Total running time of the script:** (0 minutes 10.161 seconds)


.. _sphx_glr_download__gallery_feature_demo_skinned_mesh.py:

.. only:: html

  .. container:: sphx-glr-footer sphx-glr-footer-example

    .. container:: sphx-glr-download sphx-glr-download-jupyter

      :download:`Download Jupyter notebook: skinned_mesh.ipynb <skinned_mesh.ipynb>`

    .. container:: sphx-glr-download sphx-glr-download-python

      :download:`Download Python source code: skinned_mesh.py <skinned_mesh.py>`

    .. container:: sphx-glr-download sphx-glr-download-zip

      :download:`Download zipped: skinned_mesh.zip <skinned_mesh.zip>`


.. only:: html

 .. rst-class:: sphx-glr-signature

    `Gallery generated by Sphinx-Gallery <https://sphinx-gallery.github.io>`_

.. only:: html

    Interactive example
    -------------------

    Try this example in your browser using Pyodide. Might not work with all examples and all devices. Check the output and your browser's console for details.

    .. raw:: html

        <iframe src="./../pyodide.html#skinned_mesh.py"></iframe>