Note
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Look At (Instanced Mesh)
This example shows how the look_at function can be used with instanced mesh.
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()
instance_count = 100
mesh = gfx.InstancedMesh(geometry, material, instance_count)
mesh.cast_shadow = mesh.receive_shadow = True
for i in range(instance_count):
mesh.set_matrix_at(
i,
la.mat_compose(
np.random.rand(3) * 4000 - 2000, (0, 0, 0, 1), np.random.rand() * 4 + 2
),
)
scene.add(mesh)
dummy = gfx.objects.WorldObject() # dummy object to calculate look_at
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 i in range(instance_count):
m = mesh.get_matrix_at(i)
dummy.world.matrix = m
dummy.look_at(sphere.world.position)
m = dummy.world.matrix
mesh.set_matrix_at(i, m)
if __name__ == "__main__":
disp = gfx.Display()
disp.before_render = animate
disp.show(scene)
Total running time of the script: (0 minutes 14.548 seconds)