A simple simulation in a shoebox room¶
A shoebox room built from scratch, one material per surface, simulated with image sources and ray tracing and analysed. It is the Python twin of the Grasshopper definition simple_simulation_shoebox.ghx.
The same example in Grasshopper.
"""A simple simulation in a shoebox room.
A shoebox room built from scratch, one material per surface, simulated with image sources and ray tracing
and analysed. It is the Python twin of the Grasshopper definition simple_simulation_shoebox.ghx.
"""
import compas_acoustics as ca
########### create a source and a receiver
source_1 = ca.Source(x=4.0, y=3.0, z=1.5, name="source_1")
source_2 = ca.Source(x=3.0, y=2.0, z=1.5, name="source_2")
receiver_1 = ca.Receiver(x=2.0, y=2.0, z=1.6, name="receiver_1")
receiver_2 = ca.Receiver(x=1.0, y=1.0, z=1.1, name="receiver_2")
########### create a scene
scene = ca.Scene(name="Demo Scene", description="This is a demo scene.")
########### add the sources and receivers to the scene
scene.add_source(source_1)
scene.add_source(source_2)
scene.add_receiver(receiver_1)
scene.add_receiver(receiver_2)
########### create acoustic materials
concrete = ca.AcousticMaterial(name='concrete', absorption_coefficients=[0.01, 0.01, 0.02, 0.02, 0.02, 0.05, 0.05], scattering_coefficients=[0.01, 0.01, 0.03, 0.05, 0.1, 0.1, 0.1])
brickwall = ca.AcousticMaterial(name='brickwall', absorption_coefficients=[0.01, 0.02, 0.02, 0.03, 0.03, 0.04, 0.04], scattering_coefficients=[0.01, 0.01, 0.03, 0.05, 0.2, 0.25, 0.3])
carpet = ca.AcousticMaterial(name='carpet', absorption_coefficients=[0.07, 0.31, 0.49, 0.81, 0.66, 0.54, 0.48], scattering_coefficients=0.2)
acoustic_plaster = ca.AcousticMaterial(name='acoustic_plaster', absorption_coefficients=[0.17, 0.36, 0.66, 0.65, 0.62, 0.68, 0.80], scattering_coefficients=0.2)
########### create a shoebox room, one material per surface, and add it to the scene
room = ca.AcousticObjectsLibrary.shoebox_room(length=5, width=4, height=3, materials={
'floor': carpet,
'left_wall': brickwall,
'front_wall': acoustic_plaster,
'right_wall': acoustic_plaster,
'back_wall': brickwall,
'ceiling': concrete,
})
scene.add_acoustic_objects(room)
########### run a ray tracing simulation
# Image sources plus ray tracing
rirs = scene.simulate(ca.Mono(ray_tracing=True, n_rays=10000, air_absorption=True))
########### analyze one RIR (they are keyed '<receiver guid>_<source guid>')
ir = next(ir for ir in rirs.values() if ir.receiver.name == "receiver_2" and ir.source.name == "source_2")
analyser = ca.Analyser(ir)
results = analyser.analyse()
########### print the results
analyser.print_table()
########## plot results
# analyser.plot_rir()
# analyser.plot_frequency_response(smooth=3)
analyser.plot('T30')
Output¶
125 250 500 1000 2000 4000 8000
----------------------------------------------------------------------
EDT 1.64 0.62 0.31 0.18 0.24 0.22 0.18
T20 1.26 0.78 0.25 0.22 0.22 0.20 0.18
T30 1.46 1.01 0.30 0.22 0.23 0.20 0.18
C50 -4.21 2.99 8.93 13.80 13.24 15.46 16.57
C80 2.20 6.93 20.99 22.78 20.47 23.87 27.63
D50 27.49 66.54 88.66 96.00 95.48 97.23 97.84
DRR -23.11 -7.71 -4.79 -5.89 -4.71 -5.75 -4.10
Ts 0.11 0.05 0.02 0.01 0.02 0.01 0.01
STI 0.54 0.67 0.84 0.89 0.87 0.88 0.90
G 30.04 23.35 21.51 20.08 19.86 20.84 18.87
SPL 130.04 123.35 121.51 120.08 119.86 120.84 118.87
LF nan nan nan nan nan nan nan
LFC nan nan nan nan nan nan nan