Lightmap

This example demonstrates the lightmap effects for MeshBasicMaterial, MeshPhongMaterial, and MeshStandardMaterial.

Note

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

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:

import imageio.v3 as iio
from wgpu.gui.auto import WgpuCanvas, run
import pygfx as gfx


# Init
canvas = WgpuCanvas(size=(1200, 400), title="lightmap")
renderer = gfx.renderers.WgpuRenderer(canvas)

meshes = gfx.load_gltf_mesh(model_dir / "lightmap" / "scene.gltf", materials=False)

light_map = iio.imread(model_dir / "lightmap" / "lightmap-ao-shadow.png")
light_map_tex = gfx.Texture(light_map, dim=2)

# Create camera and controller
camera = gfx.PerspectiveCamera(45, 1)
camera.local.position = 500, 1000, 1500
camera.look_at((0, 0, 0))
controller = gfx.OrbitController(camera, register_events=renderer)

# Text
text_scene = gfx.Scene()
text_camera = gfx.OrthographicCamera(12, 4)


def create_scene(material, x_pos):
    scene = gfx.Scene()
    m = meshes[0]
    material.light_map = gfx.TextureMap(light_map_tex, uv_channel=1)
    mesh = gfx.Mesh(m.geometry, material)
    mesh.local.scale = 100
    scene.add(mesh)

    t = gfx.Text(text=material.__class__.__name__, screen_space=True, font_size=20)
    t.local.position = (x_pos, 1.5, 0)
    text_scene.add(t)

    return scene


vp1 = gfx.Viewport(renderer, (5, 0, 390, 400))
scene1 = create_scene(gfx.MeshBasicMaterial(), -4)

vp2 = gfx.Viewport(renderer, (405, 0, 390, 400))
scene2 = create_scene(gfx.MeshPhongMaterial(), 0)

vp3 = gfx.Viewport(renderer, (805, 0, 390, 400))
scene3 = create_scene(gfx.MeshStandardMaterial(), 4)

vp4 = gfx.Viewport(renderer, (0, 0, 1200, 400))


def animate():
    vp1.render(scene1, camera)
    vp2.render(scene2, camera)
    vp3.render(scene3, camera)
    vp4.render(text_scene, text_camera)
    renderer.flush()


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