[Radiance-general] Revit to Radiance proof of concept

Mon Feb 29 11:25:16 PST 2016

That's pretty amazing. Thanks.

-- 
Randolph M. Fritz, Lighting Design and Simulation
+1 206 659-8617 || rmfritz3 at gmail.com

On Thu, Feb 25, 2016 at 9:22 AM, Andy McNeil <mcneil.andrew at gmail.com>
wrote:

> Wow! Thanks Schorsch! I've uploaded your email and the python script to
> radiance-online to make it easier to access in the future:
>
> http://www.radiance-online.org/download-install/third-party-utilities/revitradout
>
>
> On Thu, Feb 25, 2016 at 8:02 AM, Guglielmetti, Robert <
> Robert.Guglielmetti at nrel.gov> wrote:
>
>> Also just great to hear from you again, Schorsch!
>>
>> On 2/24/16, 5:58 PM, "Greg Ward" <gregoryjward at gmail.com> wrote:
>>
>> >Wow, Schorsch -- that's quite the unexpected gift!  We were just talking
>> >about a Revit exporter at the last Radiance workshop.  Everyone agreed it
>> >was a good idea, but no one really knew where to start.  Thanks for
>> >giving us the leg up!
>> >
>> >Cheers,
>> >-Greg
>> >
>> >> From: Georg Mischler <schorsch at schorsch.com>
>> >> Subject: [Radiance-general] Revit to Radiance proof of concept
>> >> Date: February 24, 2016 2:53:15 PM PST
>> >>
>> >> Hi all,
>> >>
>> >> I have recently had access to a Revit installation and decided to
>> >>experiment
>> >> a bit with its API. The resulting Python file is attached for anyone to
>> >>try.
>> >> I consider this a proof of concept implementation at the moment. There
>> >>are many
>> >> rough edges, and lots of features missing that would be expected in a
>> >>full blown
>> >> translator. It has been tested on the sample files supplied with Revit,
>> >>but not
>> >> on any other files.
>> >>
>> >> I may or may not have access to Revit in the coming months, so this is
>> >>what
>> >> you get for now...
>> >>
>> >>
>> >> Technical considerations
>> >>
>> >> Revit doesn't have the same geometry primitives as Radiance, but
>> >> uses B-Rep geometry in winged edge representation.
>> >> Surface elements don't close in on themselfes. This eliminates
>> >> ambiguous positioning issues for the software. For an exporter,
>> >> it means that eg. a cylinder is not one surface, but typically
>> >> composed of two half-cylinders. A circle consists of two half
>> >> arcs, etc.
>> >> Recognizing simple volume types requires analyzing and reassembling
>> >> several surface elements. This only seems to make sense for
>> >> circles/rings and cylinders (cones?) which are sufficiently easy.
>> >>
>> >>
>> >> Working features:
>> >>
>> >> * Exports all geometry visible in the active 3D view (minus RPCs)
>> >> * Seperate function for exporting topography meshes.
>> >> * cylinders and circles/rings as Radiance primitives.
>> >> * Planar faces as polygons (including holes)
>> >> * All other surfaces tesselated into triangles (rectangles for
>> >>  partial cylinders.
>> >> * Names based on level and leaf node family name (type name for
>> >>  non-family types) and material
>> >> * Metric or imperial export (configured in code)
>> >>
>> >>
>> >> To do
>> >>
>> >> * Turn into an external add-in
>> >> * Export RPCs in some way
>> >> * Export regions (parts of a surface using different color/material)
>> >> * Alternative primitive naming options (substitution lists?)
>> >> * Possibly split up the output into several files (eg. by level?)
>> >> * Detect cones (are those always coaxial in Revit?)
>> >> * Export unmodified (other than positioning/scaling) Family instances
>> >>  as seperate objects to be included via replmarks.
>> >> * Export (sufficiently large) meshes as Radiance meshes
>> >> * Export normals with curved surfaces for smoothing
>> >> * Export material properties in addition to the names
>> >> * Export light sources
>> >> * Export views
>> >> * Maybe export elements via selection instead of a complete view
>> >> * Dialog box to configure output interactively
>> >> * others?
>> >>
>> >>
>> >> Issues to research
>> >>
>> >> * It's not always easily possible to figure out on which level a
>> certain
>> >>  element resides (assuming they are associated with a level at all).
>> >> * Small objects with fine detail may result in many zero-area polygons.
>> >> * Installing an export function as a macro is clumsy. There may be a
>> >>way to create
>> >>  an external installable via the Revit Python Shell.
>> >>
>> >>
>> >> Installation
>> >>
>> >> Due to my lazyness, I created the exporter as an "Application Macro".
>> >> Not sure if it can be installed as an external add-on without changes
>> >>to the code.
>> >> To install as a macro, select the "Manage" tab, click on "Macros".
>> >> Select the "Application" tab in the opening dialog, and press "Create
>> >>Module".
>> >> Give your new application a name, chose "Python" as a language and
>> >>press "Ok".
>> >> The SharpDevelop IDE should open with a new project containing
>> >>boilerplate
>> >> code. Replace that with the contents of my file and press F8 to
>> compile.
>> >>
>> >> Now open the "Macros" dialog again, and your Module will have sprouted
>> >>two macros
>> >> named "ExportToRadiance" and "ExportTopoToRadiance". Select one of
>> >>those and
>> >> press "Run" (only works if the current view is a 3D-view).
>> >>
>> >>
>> >> Configuration
>> >>
>> >> Currently all relevant configuration happens in the code, near the top
>> >>of
>> >> the file. Configuration options are:
>> >>
>> >> * Metric or Imperial
>> >> * Output file name (default: "revout.rad" on your desktop)
>> >> * Output file name for topography (default: "revout_topo.rad" on your
>> >>desktop)
>> >>
>> >>
>> >> The attached jpg is from one of the Revit samples. The scene file is
>> >>around 50MB.
>> >> Ironically, just in this example, the Brown chair at left shows some
>> >>missing
>> >> faces at the front of the armrest... Not sure if this is my fault or
>> >>Revit's.
>> >>
>> >> Anyone who wants to try improving and extending RRadout, just go ahead
>> >>and share your
>> >> results. Depending on the feedback, I may create a Github project.
>> >>
>> >>
>> >> Have fun!
>> >>
>> >> -schorsch
>> >
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>>
>>
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