Welcome to radbsdf’s documentation!¶
radbsdf is an Python wrapper for the Radiance BSDF library.
Installation¶
Users can install radbsdf through pypi:
pip install radbsdf
You can also download/clone the repository, compile, and install locally:
git clone https://github.com/LBNL-ETA/radbsdf
cd radbsdf
pip install .
User Guide¶
A user can use radbsdf to read and analyze BSDF.
To load a tabular BSDF (.xml) file:
import radbsdf
sd_data = radbsdf.TabularBSDF("venetian_blinds.xml")
Once the BSDF is loaded, one can check BSDF summary:
sd_data.get_summary()
A summary will be printed out:
Materials: VBlinds
Manufacturer: Manufacturer
Width, Height, Thickness (m): 0.0 0.0 0.0
Peak front hemispherical transmittance: 0.026940606546542577
Peak back hemispherical transmittance: 0.029215388356407145
Peak front hemispherical reflectance: 0.1651114347940009
Peak back hemispherical reflectance: 0.16018741824894725
Diffuse Front Reflectance: 0.05820334271141809 0.05820334271141809 0.05820333924222852
Diffuse Back Reflectance: 0.052836873507863834 0.052836873507863834 0.05283687035854076
Diffuse Front Transmittance: 0.0 0.0 0.0
Diffuse Back Transmittance: 0.0 0.0 0.0
One can further examine direct hemispherical results for a given angle of incidence. Before we do that, we need to transform our coordinate systems to cartesian. For example, given an incidence theta=30° and phi=270°, we can transform the pair to Cartesian vector, ivec, like so:
tin = 30
pin = 270
theta = math.radians(tin)
phi = math.radians(pin)
x = math.sin(theta) * math.cos(phi)
y = math.sin(theta) * math.sin(phi)
z = math.cos(theta)
ivec = [x, y, z]
Once we have our angle of incidence in cartesian coordinate, we can obtain various hemispherical results like so.:
hemis_scattering = sd_data.get_direct_hemi(ivec, radbsdf.SFLAGS["Sh"])
hemis_transmittance = sd_data.get_direct_hemi(ivec, radbsdf.SFLAGS["Th"])
hemis_reflectance = sd_data.get_direct_hemi(ivec, radbsdf.SFLAGS["Rh"])
hemis_specular_transmittance = sd_data.get_direct_hemi(ivec, radbsdf.SFLAGS["Ts"])
hemis_diffuse_transmittance = sd_data.get_direct_hemi(ivec, radbsdf.SFLAGS["Td"])
hemis_specular_reflectance = sd_data.get_direct_hemi(ivec, radbsdf.SFLAGS["Rs"])
hemis_diffuse_reflectance = sd_data.get_direct_hemi(ivec, radbsdf.SFLAGS["Rd"])
We can also query the BSDF given a pair of incience and exiting angle. The outgoing angle needs also to be in Cartesian coordinate system:
sd_data.query(ovec, ivec)
In addition, we can also query the projected solid angle for a given angle of incidence:
sd_data.proj_solid_angle(ivec)