LiVi is the component of the VI-Suite that acts as a pre/post-processor for the Radiance lighting simulation suite. An installation of Radiance is therefore required. Radiance installers for Windows, OS X and Linux can be found at https://openstudio.nrel.gov/getting-started-developer/getting-started-radiance (registration required). In addition on Linux Radiance may be available to install through the distribution’s package management system. LiVi assumes that the Radiance installation is situated in the following locations:
- Windows – C:\Program Files (x86)\Radiance (64bit system) or C:\Program Files\Radiance (32bit system)
- OS X – /usr/local/radiance
- Linux – /usr/share/radiance or /usr/local/radiance
Radiance is a very advanced set of lighting simulation tools that permit the calculation of almost any lighting metric. A basic LiVi analysis can calculate illuminanace, irradiance and daylight factors. In addition, using the evalglare package included with the VI-Suite, glare can be predicted.
A basic LiVi analysis requires a minimum of three nodes: LiVi Geometry, LiVi Basic, and LiVi Simulation. A VI Location node may also be required. A typical node set-up is shown below.
LiVi Geometry exports Blender geometry and materiality to Radiance format, LiVi Basic creates a basic sky context, and LiVi Simulation runs the Radiance simulation. Display of the results is controlled from the VI Display tab in the 3D view properties panel.
A short video showing the set-up of a basic LiVi analysis can be watched below.
How can I access the calculated values of irradiation at a face center using the Atrribute node (in a material) or in python? I tried digging through the code but my current python skills fail me.
I want to feed it as the strength of emission shader on a window pane in order to reduce the noise in the cycles render for an interiors scene.
I find your work very useful in my architectural practice. Thank you.
Sorry Sal.
I’ve only just seen your post. I’m not really sure how to do this. The LiVi results are held within the mesh which can be accessed with the bmesh modules. If each face of your surface had a different material assigned you could simply write the LiVi result to the emission strength value of the material. You would not get any light directionality that way.
A better option might be the new light portal feature a Blender user has developed, which should do what you’re after. There is a discussion on BlenderArtists forum about it.
Regards
Ryan