VI-Suite v0.6 – Update 2

Dear all.

EnVi has now been transferred over to Blender 2.8, and most of the changes the user will see are within EnVi. The EnVi material system has been converted into a node system to allow up the EnergyPlus maximum of 10 layers in constructions. EnVi now supports the simulation of photovoltaics and phase change materials and you can now save your custom materials and constructions to a JSON database.

An example of EnVi Material node set-up

An example of an EnVi Material node set-up

The other major change in EnVi is that as ‘Layers’ now no longer exist in Blender – ‘Collections’ are used instead – EnergyPlus zones are specified by the Blender objects contained within collections. This allows multiple Blender objects to make up an EnergyPlus zone, and this has some advantages I hope to make use of in the future. I have not yet however finalised the logic of how muliple Blender objects become one EnergyPlus zone.

In other news the VI-Suite is now completely self-contained within the addon zip folder (at least on Windows and Linux). This means that you can install in Blender the git zip directly, and it will hopefully make it easier to get the VI-Suite working on a variety of Linux platforms.

I have general bug fixing still to do and Wind Rose display to finish, but I am hoping to announce a beta release for testing soon.

There is one fly in the ointment. The Blender 2.8 series does not currently allow the keyframing of custom node parameters. As most of the Vi-Suite parameters exposed to the user are custom node parameters, it means that automated parametric analysis is largely not possible.  This has been recognised by the Blender developers and if you want to register your interest in getting this fixed you can do so at The more people asking for it to be fixed the more likely it is to be fixed.



VI-Suite v0.6 – Update

Dear all.

As some people have been asking what my plans are regarding a Blender 2.8 version of the VI-Suite, I thought I would post an update.

The eagle-eyed amongst you may have noticed that the title of this post skips a version. v0.5 was going to be the last VI-Suite version of the 2.7 series but as 2.8 is now out I decided to roll those changes in to v0.6.

Over the last couple of weeks sun path, wind rose, shadow maps, sky view factor and LiVi have all been, at least in part, transfered over. I am in the process of tranferring EnVi over. There are many bugs remaining, and I would not say v0.6 is ready for usage, but good progress is being made. I’m hopeful that early next year an initial release might be ready.

Once things have stabilised a bit I will post the link to the github repository here.



Blender 2.8 - LiVi

LiVi in Blender 2.80


VI-Suite v0.4.13a & Ubuntu 18.04

I have pushed version 0.4.13a to the download links which fixes an EnVi bug to account for syntax changes in EnergyPlus 8.9.

In other news, a couple of users have told me that the VI-Suite works on Ubuntu 18.04. I can confirm that their method does work on a fresh install of 18.04, although I have had problems running it on an 18.04 system that was upgraded from 16.04.

The process is pretty simple.

Make sure there is no existing Blender installation

Install Blender from a PPA with the terminal commands:

sudo add-apt-repository ppa:thomas-schiex/blender

sudo apt-get update

sudo apt-get install blender

This version of Blender should use the system installed Python distribution which will now require the ancillary libraries. To install these use the terminal commands:

sudo apt-get install python3-psutil

sudo apt-get install python3-pyqt5

sudo apt-get install python3-matplotlib

sudo apt-get install python3-kivy

The last command to install kivy should work in future but the current Python 3 version of kivy (1.9.1) is broken on Ubuntu 18.04. To get round this:

sudo add-apt-repository ppa:kivy-team/kivy-daily

sudo apt-get update

sudo apt-get install python3-kivy

I have changed the tar.gz compressed Linux VI-Suite download to a zip compressed one on the main download page. This can be installed directly from the Addons page within Blender’s User Preferences window with the Install-addon-from-file button. Alternatively, decompress and copy the folder to Blender’s Addon directory as before.

VI-Suite v0.4 – Version 0.4.13 and Radiance Images

Irradiance falsecolour image

Irradiance falsecolour  image

I have just uploaded VI-Suite 0.4.13 to the download links at Changes in this version can be seen in the Changelog. One of the main new features of this version is the LIVi image nodes which enables the generation and manipulation of Radiance images for falsecolour metric visualisation and glare analysis.

Images can be generated in parallel on multi-core machines when using OS X and Linux. Unfortunately the methodology employed will not work on Windows.

As ever the tutorial video below explains their operation.


VI-Suite v0.4 – Publication

An article describing the VI-Suite has been published in ‘Open Geospatial Data, Software and Standards’. As the article is open-access, the full text can be accessed from The article was co-authored with Filip Biljecki from TU Delft/National University of Singapore and examines the VI-Suite from a geospatial data perspective.

Southall, R., Biljecki, F.
The VI-Suite: a set of environmental analysis tools with geospatial data applications
Open Geospatial Data, Software and Standards 2(1), Sep 2017, 23
Abstract: The VI-Suite is a free and open-source addon for the 3D content creation application Blender, developed primarily as a tool for the contextual and performative analysis of buildings. Its functionality has grown from simple, static lighting analysis to fully parametric lighting, shadowing, and building energy analyses. It adopts a flexible, mesh geometry based approach to the specification of calculation points and this has made it suitable for certain types of 3D geospatial analyses and data visualisation.


As this is the first paper that describes the VI-Suite the article can be used to cite the VI-Suite. The bibtext formatted citation can be downloaded here.

An image from the paper is shown below.


Annual irradiance on a building facade

VI-Suite v0.4 – Version 0.4.12

I have just released version 0.4.12 of the VI-Suite. Minor changes this time but there was a nasty bug when setting an air layer in an EnergyPlus wall construction and I felt the fix deserved a new release. As part of fixing this bug I introduced a tiny new feature which is to display an indicative U-values in the ‘Material’ tab for exported material associated with layer 2 EnVi geometry. This indicative U-value assumes the material is on an external surface and uses internal and external surface resistances of 0.12 and 0.08 m²K/W respectively.

There is also a new option in the LiVi Geometry node called ‘Fallback’. Turning this on makes LiVi export a pure polygon Radiance geometry description. This is more reliable and is indeed faster to simulate in simple cases but will ignore any specified smooth shading,  textures or normal maps.

VI-Suite v0.4 – Version 0.4.11 & Sky View Factor Calculation

Version 0.4.11 has now been released. This version contains a number of bug fixes and new features,  including the ability to create a sun path with hourly or monthly suns and a new Sky View Factor node. A zip file containing the VI-Suite addon for Blender version 2.7.8 has also been released for Linux 64bit systems. See the changelog page for more details.

The sky view factor (or VI SVF) node operates in a similar manner to the Shadow Map node except that instead of checking if a point can be seen from the perspective of simulated sun positions it is checked if it can be seen from different portions of the sky. The sky can be subdivided into 145 portions (Tregenza) 577 portions (Reinhart 577) or 2305 portions (Reinhart 2305). Accuracy and simulation time increases with each one.

The VI Sky View Factor node can be added through the ‘Analysis Nodes’ menu. An image of the node is shown below. Options are similar as for the Shadow Map node except there is no location input required and no time options, as sky view factor is location and time independent. The ‘Results Out’ socket can be used to save the results to CSV file.

SVF Node

Sky View Factor Node

An example analysis with a 3D city model of the Hague in the Netherlands can be seen below.

SVF analysis

Sky View Factor analysis of the Hague. Model provided courtesy of Filip Biljecki.


VI-Suite v0.4 – Radiance Textures

Normal mapping

Radiance render with multiple normal maps

This tutorial is basically a follow up to the Radiance Patterns tutorial and details how normal maps can be used to specify Radiance textures. Textures in Radiance terminology is a perturbation to the surface normal to give the impression that the surface has detailed physical features. If for example a point on a surface has its normal perturbed towards a light source the point will receive more light than if the surface normal is perturbed away.

Although, like Radiance patterns, textures are not often necessary for numerical lighting simulation, and indeed are ignored if they are on an illuminance sensing surface, they can provide extra realism to visual Radiance renders and there are certain circumstances where they may be useful numerically and/or save time by not requiring the creation of detailed physical geometry.

The video below details the process.

VI-Suite v0.4 – Artificial Lighting Simulation

Lighting simulation of Blender's classroom scene

Radiance visual and falsecolour rendering of Blender’s classroom scene

The VI-Suite can simulate artificial as well as natural lighting. Three main methods are available:

  • Specifying a Radiance light material to mesh elements.
  • Associating an IES file with a Blender lamp.
  • Associating an IES file with a Blender mesh plane to create an array of lights.

IES files, which are text files describing the brightness of a lamp or luminaire from different viewing angles, are released by manufacturers for their specific lighting products and can usually be downloaded from their websites. This gives the opportunity to see how real world products will illuminate a scene visually and with the VI-Suite numerically.

As ever, the video below describes these three methods.