Boundary Boxes

Demonstrates visualizing object bounding boxes

Warning

An external model is needed to run this example.

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
from importlib.util import find_spec

if not find_spec("open3d"):
    raise ImportError(
        "The `open3d` library is required for this example: pip install open3d"
    )

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:

from open3d import io
import open3d as o3d
import pygfx as gfx
import pylinalg as la

# load teapot with open3d
teapot: o3d.geometry.TriangleMesh = io.read_triangle_mesh(
    str(model_dir / "teapot.stl"), enable_post_processing=True
)

# open3d does not seem to read stl files with normals -> re-compute them
teapot.compute_vertex_normals()

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

mesh = gfx.Mesh(
    gfx.geometries.geometry_from_open3d(teapot),
    gfx.MeshPhongMaterial(),
)
mesh.local.rotation = la.quat_from_euler((0.71, 0.91), order="XY")
scene.add(mesh)

box_world = gfx.BoxHelper(color="red")
box_world.set_transform_by_object(mesh)
scene.add(box_world)

box_local = gfx.BoxHelper(thickness=2, color="green")
box_local.set_transform_by_object(mesh, space="local")
mesh.add(box_local)  # note that the parent is `mesh` here, not `scene`

if __name__ == "__main__":
    disp = gfx.Display()
    disp.show(scene, up=(0, 0, 1))