Daylighting Program

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Bldg-Sim Group:
Are there daylighting design programs that interface with Google
SketchUp Pro?
Mark Zoeteman

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Mark,

DAYSIM tutorial has information on how it can utilize a SketchUp model for
daylight analysis.

I don't think the choice of materials that can be assigned from within
SketchUp is that comprehensive yet. I haven't tried that route in a while so
unless it can already be done, I'd be interested in hearing from Christoph,
the author of DAYSIM, on when we'll be able to assign user created materials
to surfaces within SketchUp before exporting to DAYSIM.

RAMANA KOTI 

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Hi Mark,

You could use the IES VE plugin for Sketchup Pro which will allow you to
bring your model into the and use modules like
FlucsDL or Radiance to help you optimise your building for daylighting
and glare control. Please go to www.iesve.com for more details or call
the office at 1 617 426 1890.

Regards

Pete Murray

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If you have 3DS max, you could export a sketchup file to it. Max now has
a daylight simulation engine similar to Daysim (in fact I think
Christoph Reinhart was involved with its development)

Vikram Sami, LEED AP

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Rob Guglielmetti's picture
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Gidday All

There are two lighting programs that I am aware of that 'interface' with Google SketchUp (standard or Pro):

ONE: Radiance
Daysim (http://irc.nrc-cnrc.gc.ca/ie/lighting/daylight/daysim_e.html ) which models the annual availability of daylight inside buildings using the rigorously validated (http://lrt.sagepub.com/cgi/content/abstract/27/4/181 ) render engine Radiance (http://radsite.lbl.gov/radiance/ ) as its underlying calculation engine. However, it should be pointed out that 'integration' means that IF you have the Pro version of SU, THEN you can export to the .3ds file format that the Daysim program will import. The author, Christoph Reinhart, has referred recently to Daysim 3 being in the process of validation and incorporating some of the newer daylight performance metrics - but no reference to greater integration with SU.

Radiance in its raw form can be used simply on a file exported by Thomas Bleicher's su2rad (https://www.ohloh.net/p/su2rad ) exporter. Saved scenes become saved viewpoints in Radiance. Materials and skies can be defined within SU prior to export. There is as yet no render control 'button' within the exporter interface, but everything else is there. Running Radiance of course requires a knowledge of Unix (see http://luminance.londonmet.ac.uk/learnix/ ) or having a copy of Ecotect's Radiance Control Panel (www.ecotect.com ) and the Windows executables for Radiance (http://www.bozzograo.net/radiance/modules.php?op=modload&name=Downloads&file=index&req=viewdownload&cid=4 - the MinGW version) This works with both the versions of SU.

IES has a plugin (http://www.iesve.com/content/default.asp?page=s156 ) which will export from SU to their Virtual Environment format. If you have bought their full product, then you will again have access to Radiance, which as I understand it is distributed as the render engine for IES. I understand this works with both the versions of SU.

TWO: 3DS Max
mentalray within the 3DS Max software from Autodesk (http://usa.autodesk.com/adsk/servlet/index?id=5659302&siteID=123112 ) has been validated recently (http://images.autodesk.com/adsk/files/3ds_max_design-exposure_validation.pdf ) by Christoph Reinhart. To transfer files from SU again you will need the Pro version.

Michael Donn

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Dear Mark and others,

Interesting threat. Michael listed a series of workflows that one can
use to analyze a SketchUp scene using either Radiance or 3ds Max
Design/Mental Ray. Michael also pointed out that these two simulation
engines have been successfully validated based on measured indoor
illuminances. Before picking any of these workflows I recommend that you
first carefully decide what you actually want to calculate using
daylight simulations.

* For a LEED 8.1 Daylighting Credit compliance simulation most
of the work flows described by Michael should work since the 'old' CIE
clear sky as well as the CIE overcast sky (for daylight factor
calculations) are supported by Radiance and 3ds Max. If this is your
objective it is worthwhile mentioning that there are many designs that
fail the LEED glazing/daylight factor requirement according to
simulations but meet it via the spreadsheet method from the LEED
technical manual (see p.32:
www.gsd.harvard.edu/people/faculty/reinhart/documents/DiffuseDaylighting
DesignSequence.pdf) .

* For physically based images both engines can be used (pay
attention that you actually use Mental Ray as the engine for your 3ds
Max simulations). Mental Ray tends to be faster than Radiance but
Radiance offers richer analysis capabilities including various glare
indices (if one is willing to use Radiance via the command line).

* Climate-based daylighting metrics have been proposed to be
superior design measures than the daylight factor
(http://irc.nrc-cnrc.gc.ca/pubs/fulltext/nrcc48669/nrcc48669.pdf
) and
IESNA and CIE are currently working on benchmark levels for these
metrics. To calculate a climate-based metric you can use Daysim, SPOT
and (in principal) even 3ds Max. The caveat for 3ds Max is that the
calculations would currently take a long time (page 29
www.autodesk.com/us/3dsmaxdesign/B3241.MentalRayValidation_v3.pdf
).

* For integrated lighting-thermal simulations one can either use
a build-in method (e.g. in EnergyPlus or DOE2.1) or link the thermal
simulation program with externally calculated annual illuminance
profiles. The latter methods tends to be more accurate.

assigned from within SketchUp is that comprehensive yet ... I'd be
interested in hearing from Christoph ... when we'll be able to assign
user created materials to surfaces within SketchUp before exporting to
DAYSIM.

We once had a good workflow from Sketchup 4 to Daysim via the 3ds format
that allowed the user to use a custom material library in SketchUp to
automatically assign materials in Daysim. The 3ds export file format in
SketchUp 5 was unfortunately slightly changed so that this workflow is
not valid any more. I am now using Thomas Bleicher's earlier mentioned
SketchUp to Radiance exporter. I find the only 'hiccup' with this
approach to be that the exporter writes out all layers into separate
files which have to be individually imported into Daysim. I also have to
manually assign the materials, i.e. there is still room for improvement.

A general warning for any daylight simulations based on a SketchUp scene
is that SketchUp allows to assign different material properties to the
two surfaces of a polygon. This leaves room for errors since Radiance
only recognizes one material type per polygon.

Christoph Reinhart, Dr. Ing.

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