Radiance’s Photon Mapping capability can really help a backwards raytracer like Radiance achieve good results in situations where it is difficult for backwards rays fired from the camera or sensor point to find a light source e.g. interior scenes with small windows or small artificial lights.
The video below shows how to turn on and use photon mapping in the VI-Suite. The current implementation in the VI-Suite only works with natural lighting. When I have it working with artificial lights I’ll update this post.
If you’re doing building modelling outside of Blender and importing the geometry into Blender for analysis with the VI-Suite there are some things to bear in mind, especially if the other application is not a mesh modeller like Blender e.g. Rhino, Sketchup.
If possible export the model from the other application with the unit as metres as Blender will interpret the unit as Blender units which are equivalent to 1m in the VI-Suite. Also make sure that your model is situated appropriately relative to the origin point in the other application. If importing 1 building for example put the building near the origin point before exporting.
For most types of analyses with the VI-Suite exporting the geometry as one OBJ or 3ds object can be useful as it makes manipulation of the geometry in Blender a bit easier. If doing an EnergyPlus simulation with EnVi, exporting an object for each thermal zone you wish to simulate is optimal.
Applications like Rhino and Sketchup also have to convert their native geometry for export to 3ds or OBJ files for import into Blender, and this conversion can lead to very messy mesh geometry. The Blender tools ‘Remove Doubles’ and ‘Limited Dissolve’ can help you clean up this geometry.
The video below shows how to prepare imported geometry in Blender for simulation with the VI-Suite.
Below is a video showing how to conduct a simple lighting analysis with Radiance using the LiVi component of the VI-Suite. A simple analysis allows the prediction of Lux, Daylight Factor, Visible Irradiance and Full Irradiance.
The video below details how to conduct a shadow mapping analysis with the VI-Suite. In this context shadow mapping is the prediction of how often points in space are in direct sunlight when the sun is above the horizon. Simulations with the VI-Suite can be done for any portion of the year and use any mesh geometry within the scene as the calculation points. The example image below shows an annual shadow map, with 4 calculations per hour, using the urban building geometry as the calculation points. One of the advantages of this approach is that once the simulation is complete the results are fully navigable in Blender.
I’ve just updated the VI-Suite to version 0.4.2. This version contains various bug fixes and an update to this version is recommended by downloading the complete zip file from http://arts.brighton.ac.uk/projects/vi-suite/downloads for your operating system.
One user-facing change is that if specifying a custom EPW weather file in the VI-Suite settings the Manual/EPW menu needs to be toggled in the location node to update the weather file list.
A couple of changes have been made to the wind rose creation capabilities in version 0.4. The colour mapping of the created wind rose can now be selected within the wind rose node and wind metrics can now be displayed within the 3D scene using the VI-Suite’s new display framework.
There have been a couple of changes to the sun path capabilities in version 0.4. Sun paths can now be rotated, some sun characteristics can now be overlaid onto the 3D view in addition to the sun path hours and summer/equinox/winter sun azimuth ranges are now included in the sun path object.
The VI Chart node can accept data from the VI Location, LiVi Simulation, EnVi Simulation, and Shadow Study nodes and offers 2D plotting of weather/results metrics with matplotlib. The tutorial video below details the options and operation of this node.
I am very happy to announce the general availability of VI-Suite version 0.4. Some user-preferences have been added in this version and the tutorial video below details these changes along with activating the VI-Suite and creating your first node. The video assumes you have downloaded the zip file for your platform from the main VI-Suite website and extracted the folder within to somewhere on your computer. Remember that the destination for the folder should not have any spaces in it so ‘/Users/ryan/Desktop’ would be fine but ‘/Users/ryan/My Folder’ would not.
In this, probably the last version 0.3 video tutorial, I cover parametric Radiance analysis with LiVi. As parametric analysis in the VI-Suite is done using Blender’s animation system I cover the very basics of setting up animation in Blender and the export, simulation and visualisation of the Radiance analyses.
Although it will a while before I release version 0.4 I will soon start putting up sneak-peak videos of what to expect in the next version.
