Look At

This example shows how the look_at function can be used.

from time import perf_counter
import numpy as np
import pygfx as gfx
import pylinalg as la

scene = gfx.Scene()

sphere = gfx.Mesh(
    gfx.sphere_geometry(100, 20, 20),
    gfx.MeshPhongMaterial(color="#336699"),
)
sphere.receive_shadow = sphere.cast_shadow = True
scene.add(sphere)

plane = gfx.Mesh(
    gfx.plane_geometry(4000, 4000),
    gfx.MeshPhongMaterial(color="#336699"),
)
plane.local.position = (0, -2500, 0)
plane.local.rotation = la.quat_from_euler(-np.pi / 2, order="X")
plane.receive_shadow = True
scene.add(plane)

sun = gfx.DirectionalLight()
sun.local.position = (0, 3000, 0)
sun.cast_shadow = True
sun.shadow.camera.depth_range = (1, 6000)
sun.shadow.camera.width = 4000
sun.shadow.camera.height = 4000
scene.add(gfx.AmbientLight())
scene.add(sun)

geometry = gfx.cylinder_geometry(10, 0, 100, 12)
material = gfx.MeshPhongMaterial(color="#336699")
cones = gfx.Group()

for i in range(100):
    cone = gfx.Mesh(geometry, material)
    cone.local.position = np.random.rand(3) * 4000 - 2000
    cone.local.scale = np.random.rand() * 4 + 2
    cone.receive_shadow = cone.cast_shadow = True
    cones.add(cone)

scene.add(cones)


def animate():
    t = perf_counter() / 0.5
    sphere.local.position = (
        np.sin(t * 0.7) * 2000,
        np.cos(t * 0.5) * 2000,
        np.cos(t * 0.3) * 2000,
    )

    for c in cones.children:
        c.look_at(sphere.world.position)


if __name__ == "__main__":
    disp = gfx.Display()
    disp.before_render = animate
    disp.show(scene)