Rayfront-Announce Newsletter Archive

Issue Nr. 1
Mar. 19th 2000.

Contents:

• Rayfront Extension for Daylight Redirection Systems
• Rayfront Presented at Otti Symposion on Innovative Lighting Technology in Buildings
• Daylight Redirection Systems Illustrated
• Further Plans and Short News
• Other Newsletter Issues

Rayfront Extension for Daylight Redirection Systems

I have started a very promising collaboration with Thomas Schmidt of Exergia (http://www.exergia.de/, currently in german only). Thomas has written an extension for Radiance, which allows to integrate most daylight redirection systems into a simulation. As a first step, the 2D forward raytracer Osim computes the exact behaviour of the elements for every incident angle of light. This data is then used by the preprocessor Mktis, which can be used in a way similar to mkillum, but takes precise account of solar as well as diffuse irradiance.

I have adapted Rayfront to use Mktis, so that the user can select one of the redirection elements in the library and "apply" it to a window. The simulation will then take all the necessary steps to run the program with the right data. This feature will be available as a plug-in module to Rayfront, at a yet undetermined price. To the best of my knowledge, this will make Rayfront the only software package available on the global market that offers such a general possibility to compute the effects of daylight redirection systems.

The simulations can include all translation-invariant structures (aka. extrusion profiles) with mirrored or refracting internal surfaces. The most obvious examples are all kinds of mirrored surface louver systems, within glazings or open. The other class of elements includes prism panels, lasercut panels and curved acrylic strips that are stapled within insulation glazings and are currently becoming more and more popular in europe.

Rayfront Presented at Otti Symposion on Innovative Lighting Technology in Buildings

End of january we could demostrate Rayfront and Osim/Mktis at the "6th Otti Symposion on Innovative Lighting Technology in Buildings", a yearly convention that brings together most innovative lighting specialists from the german speaking contries and beyond. We were able to talk with many important personalities from the industry and were generally met with positive interest. The contacts we could initiate there will make it much easier to collect the data needed for bundling as many daylight systems as possible for your simulations.

All in all, those two days reassured me a lot that there is a real demand for a tool like Rayfront. It was interesting to see that almost one out of three posters in the poster exhibition had some kind of Radiance simulation on display. This demonstrates that, at least in the research community, Radiance is an established tool, even if not all users are happy with its useability. Many people approached me with descriptions of the troubles they had to fight in their projects, asking if Rayfront would make their job easier. In the majority of the cases I was very happy to confirm that!

Daylight Redirection Systems Illustrated

As a byproduct of the demonstration above and an article I'm just publishing about daylighting in banks, I ended up with a number of diagrams depicting many of the currently available daylighting systems. I have made the full collection available with short explanations. This display will be enhanced with more details about the actual products as soon as I have collected more information from each manufacturer. Some brand new systems are not mentioned yet, but I'll add them soon. And of course, if you know of anything that I might have missed, please tell me and if it can be simulated with Radiance, I'll include it in this presentation.

As an interesting side note: My perspective may be biased here, but I have yet to see an industrially manufactured daylighting system for the vertical facade that was developed outside europe, or even outside of germany, austria or switzerland. Is there really such an enormous lack of ingeniosity elsewhere, have I been blind to things happening in the rest of the world, or what is going on here? Yes, I know about solatube and similar systems, but usually those only handle sunlight. In contrast to that, most industrialized countries are located in moderate climatic zones, where diffuse daylight from the sky or cloud cover should be much more important. I'd be highly interested in what people in other places know about this!

Further Plans and Short News

The Rayfront developement currently revolves around the following topics:

Job scheduling
The mechanics for scheduling simulation jobs for sequential execution are in place. I'll invent a good user interface for actually using this very soon. The general model for scheduling jobs is pretty simple and convenient, wich will be good enough for most cases. For more complex environments, there is a good chance that I'll be able to offer another extension module for Rayfront, which solves every conveivable job distribution problem. More details about this later, when/if the license negotiations show first results.

Autocad integration
First experiments at embedding Rayfront as an ARX application within Autocad have been a success. Spinning off from this work, I'll make a Python wrapper of the ADS API available as an open source project. If none of those acroyms means anything to you, don't worry. Only a certain strange kind programmers needs to waste their mental energy on this.

Luminaire selection
A better user interface for luminaire data import and selection is needed soon. More about that hopefully in the next issue of this newsletter.

Speaking of luminaire data:
I am considering to offer a luminaire data format conversion service on www.schorsch.com. Since I already have the code to read IES, Eulumdat and CIBSE TM14 format data, the additional effort to also write those formats shouldn't be too daunting. Creating a useful web interface to this functionality will be harder, so it may as well take a few weeks until I find the time to implement this. While all the formats involved are fairly simple, they are sufficiently different to make this a nontrivial task. The service will have to offer lots of configuration options to become really useful.

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