Rendering with instanced geometries

This test demonstrates rendering with multi-level instancing.

%load_ext autoreload
%autoreload 2

# Imports
import os
import traceback
import imageio
import pandas as pd
import numpy as np
%matplotlib inline
import matplotlib.pyplot as plt
from mpl_toolkits.axes_grid1 import make_axes_locatable
import lmfunctest as ft
import lmscene
import lightmetrica as lm

os.getpid()

979

%load_ext lightmetrica_jupyter

# Initialize Lightmetrica
lm.init()
lm.log.init('logger::jupyter')
lm.progress.init('progress::jupyter')

lm.comp.loadPlugin(os.path.join(ft.env.bin_path, 'accel_embree'))
lm.comp.loadPlugin(os.path.join(ft.env.bin_path, 'accel_nanort'))

[I|0.018|179@compon] Loading plugin [name='accel_embree']
[I|0.019|197@compon]   Successfully loaded
[I|0.019|179@compon] Loading plugin [name='accel_nanort']
[I|0.019|197@compon]   Successfully loaded

True

# Create a sphere geometry with triangle mesh
r = 1
numTheta = 10
numPhi = 2*numTheta
vs = np.zeros((numPhi*(numTheta+1), 3))
ns = np.zeros((numPhi*(numTheta+1), 3))
ts = np.zeros((numPhi*(numTheta+1), 2))
for i in range(numTheta+1):
    for j in range(numPhi):
        theta = i*np.pi/numTheta
        phi = j*2*np.pi/numPhi
        idx = i*numPhi+j
        ns[idx,0] = np.sin(theta)*np.sin(phi)
        ns[idx,1] = np.cos(theta)
        ns[idx,2] = np.sin(theta)*np.cos(phi)
        vs[idx,0] = r*ns[idx,0]
        vs[idx,1] = r*ns[idx,1]
        vs[idx,2] = r*ns[idx,2]

fs = np.zeros((2*numPhi*(numTheta-1), 3), dtype=np.int32)
idx = 0
for i in range(1,numTheta+1):
    for j in range(1,numPhi+1):
        p00 = (i-1)*numPhi+j-1
        p01 = (i-1)*numPhi+j%numPhi
        p10 = i*numPhi+j-1
        p11 = i*numPhi+j%numPhi
        if i > 1:
            fs[idx,:] = np.array([p10,p01,p00])
            idx += 1
        if i < numTheta:
            fs[idx,:] = np.array([p11,p01,p10])
            idx += 1

# Scene setup
def scene_setup():
    lm.reset()
    lm.asset('mesh_sphere', 'mesh::raw', {
        'ps': vs.flatten().tolist(),
        'ns': ns.flatten().tolist(),
        'ts': ts.flatten().tolist(),
        'fs': {
            'p': fs.flatten().tolist(),
            't': fs.flatten().tolist(),
            'n': fs.flatten().tolist()
        }
    })
    lm.asset('camera_main', 'camera::pinhole', {
        'position': [0,0,50],
        'center': [0,0,0],
        'up': [0,1,0],
        'vfov': 30
    })
    lm.asset('material_white', 'material::diffuse', {
        'Kd': [1,1,1]
    })
    lm.primitive(lm.identity(), {
        'camera': lm.asset('camera_main')
    })

# Rendering
def render_and_visualize():
    lm.build('accel::nanort', {})
    lm.asset('film_output', 'film::bitmap', {'w': 1920, 'h': 1080})
    lm.render('renderer::raycast', {
        'output': lm.asset('film_output'),
        'visualize_normal': True,
        'bg_color': [1,1,1]
    })
    img = np.copy(lm.buffer(lm.asset('film_output')))
    f = plt.figure(figsize=(15,15))
    ax = f.add_subplot(111)
    ax.imshow(np.clip(np.power(img,1/2.2),0,1), origin='lower')
    plt.show()

Without instancing

scene_setup()
for y in np.linspace(-10,10,10):
    for x in np.linspace(-10,10,10):
        p = lm.primitiveNode({
            'mesh': lm.asset('mesh_sphere'),
            'material': lm.asset('material_white')
        })
        t = lm.transformNode(lm.translate(np.array([x,y,0])))
        lm.addChild(t, p)
        lm.addChild(lm.rootNode(), t)

[I|0.111|48@assets ] Loading asset [name='mesh_sphere']
[I|0.112|48@assets ] Loading asset [name='camera_main']
[I|0.113|48@assets ] Loading asset [name='material_white']

render_and_visualize()

[I|0.133|246@scene ] Building acceleration structure [name='accel::nanort']
[I|0.133|38@accel_n]   Flattening scene
[I|0.138|68@accel_n]   Building
[I|0.190|48@assets ] Loading asset [name='film_output']
[I|0.279|151@user  ] Starting render [name='renderer::raycast']

Single-level

scene_setup()

# Instance group
g = lm.instanceGroupNode()
lm.addChild(g, lm.primitiveNode({
    'mesh': lm.asset('mesh_sphere'),
    'material': lm.asset('material_white')
}))

# Transformed instanced group
for y in np.linspace(-10,10,10):
    for x in np.linspace(-10,10,10):
        t = lm.transformNode(lm.translate(np.array([x,y,0])))
        lm.addChild(t, g)
        lm.addChild(lm.rootNode(), t)

[I|2.590|48@assets ] Loading asset [name='mesh_sphere']
[I|2.590|48@assets ] Loading asset [name='camera_main']
[I|2.590|48@assets ] Loading asset [name='material_white']

render_and_visualize()

[I|2.611|246@scene ] Building acceleration structure [name='accel::nanort']
[I|2.612|38@accel_n]   Flattening scene
[I|2.615|68@accel_n]   Building
[I|2.664|48@assets ] Loading asset [name='film_output']
[I|2.752|151@user  ] Starting render [name='renderer::raycast']

Multi-level

scene_setup()

# Initial group
g1 = lm.instanceGroupNode()
lm.addChild(g1, lm.primitiveNode({
    'mesh': lm.asset('mesh_sphere'),
    'material': lm.asset('material_white')
}))

# Second group using initial group as chilren
g2 = lm.instanceGroupNode()
for y in np.linspace(-10,10,10):
    t = lm.transformNode(lm.translate(np.array([0,y,0])))
    lm.addChild(t, g1)
    lm.addChild(g2, t)

# Add transformed second group to the root node
for x in np.linspace(-10,10,10):
    t = lm.transformNode(lm.translate(np.array([x,0,0])))
    lm.addChild(t, g2)
    lm.addChild(lm.rootNode(), t)

[I|5.034|48@assets ] Loading asset [name='mesh_sphere']
[I|5.035|48@assets ] Loading asset [name='camera_main']
[I|5.035|48@assets ] Loading asset [name='material_white']

render_and_visualize()

[I|5.055|246@scene ] Building acceleration structure [name='accel::nanort']
[I|5.055|38@accel_n]   Flattening scene
[I|5.058|68@accel_n]   Building
[I|5.107|48@assets ] Loading asset [name='film_output']
[I|5.198|151@user  ] Starting render [name='renderer::raycast']