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PBR Rendering 2
This example shows the lighting rendering affect of materials with different metalness and roughness. Every second sphere has an IBL environment map on it.

import math
from time import perf_counter
import imageio.v3 as iio
from wgpu.gui.auto import WgpuCanvas, run
import pygfx as gfx
import pylinalg as la
# Init
canvas = WgpuCanvas(size=(640, 480), title="gfx_pbr")
renderer = gfx.renderers.WgpuRenderer(canvas)
scene = gfx.Scene()
# Lights
scene.add(gfx.AmbientLight("#fff", 0.2))
directional_light = gfx.DirectionalLight("#fff", 3)
directional_light.local.position = la.vec_normalize((1, 1, 1))
scene.add(directional_light)
point_light = gfx.PointLight("#fff", 3)
scene.add(point_light)
point_light.add(gfx.PointLightHelper(4))
# Read cube image and turn it into a 3D image (a 4d array)
env_img = iio.imread("imageio:meadow_cube.jpg")
cube_size = env_img.shape[1]
env_img.shape = 6, cube_size, cube_size, env_img.shape[-1]
# Create environment map
env_tex = gfx.Texture(
env_img, dim=2, size=(cube_size, cube_size, 6), generate_mipmaps=True
)
# Apply env map to skybox
background = gfx.Background(None, gfx.BackgroundSkyboxMaterial(map=env_tex))
scene.add(background)
# Now create spheres ...
cube_width = 400
numbers_per_side = 5
sphere_radius = (cube_width / numbers_per_side) * 0.8 * 0.5
step_size = 1.0 / numbers_per_side
geometry = gfx.sphere_geometry(sphere_radius, 32, 16)
index = 0
alpha = 0.0
while alpha <= 1.0:
beta = 0.0
while beta <= 1.0:
gamma = 0.0
while gamma <= 1.0:
material = gfx.MeshStandardMaterial(
color=gfx.Color.from_physical(
*gfx.Color.from_hsl(alpha, 0.5, gamma * 0.5 + 0.1)
),
metalness=beta,
roughness=1.0 - alpha,
)
if index % 2 != 0:
material.env_map = env_tex
mesh = gfx.Mesh(geometry, material)
mesh.local.position = (
alpha * 400 - 200,
beta * 400 - 200,
gamma * 400 - 200,
)
scene.add(mesh)
index += 1
gamma += step_size
beta += step_size
alpha += step_size
# Create camera and controls
camera = gfx.PerspectiveCamera(45, 640 / 480)
camera.show_object(scene, view_dir=(-2, -1.5, -3), scale=1.2)
controller = gfx.OrbitController(camera, register_events=renderer)
t0 = perf_counter()
def animate():
t = perf_counter() - t0
t = t * 0.25
point_light.local.position = (
math.sin(t * 7) * 300,
math.cos(t * 5) * 400,
math.cos(t * 3) * 300,
)
renderer.render(scene, camera)
renderer.request_draw()
if __name__ == "__main__":
renderer.request_draw(animate)
run()
Total running time of the script: (0 minutes 54.461 seconds)