[Radiance-general] Re: radiance question
Lars O. Grobe
grobe at gmx.net
Fri Aug 20 13:33:58 CEST 2004
Hi,
just three ways:
Use dxf. This makes sense if you are e.g. working with AutoCAD. Get
Georg Mischlers dxf2rad (www.schorsch.com), which is available for a
lot of platforms. When exporting, take care of the units (I have always
1unit=1meter, so the same as in most radiance apps). Use different
layers for materials. dxf2rad will use the layernames as modifiers in
the exported rad-model. Than write a material-mapping file, using
aliases. That way, you can use ONE material file, that you will re-use
for all your projects (simply adding new materials when needed) and put
all the layer-to-material information into the mapping-file, that will
be valid just for the model. If you are working on Mac or Unix, make
sure to encode the (ascii)-dxf file in the ms-dos world format.
Use obj. This is available as an export option for different
3d-packages. It is supported by obj2rad and the new mesh primitive in
Radiance. Be careful, the coordinate system in radiance is with the
z-achis up! Many of these modeler use other coordinate systems! The
obj-export will often be triangulated, but you can use surface normals
(e.g. for smoothing) and texture coordinates. As such, I would always
prefer it for the not-so-classic architectural models containing lots
of curved surfaces.
Use 3ds. This means that you first convert to mgf, than to rad. You can
get "smoothed" surfaces like with obj, and 3ds is available in many
3d-modelers, too. You can get some simple material definitions based on
the 3ds-file, so you should be able to view the exported rad-file
without changes by objview (the other formats' importers don't use the
material / color information). However, some of the advanced features
radiance offers with obj now are not available with 3ds (tecture
coordinates).
If you have a big model, and used some kind of blocks (symbols,
references, however your cad calls them), you can try to import them as
instances or by using xform. This might help to reduce the memory
needed during rendering a lot, however, it adds complexity to the
import. Maybe we will have a converter that can handle blocks and
export them as such to radiance without user interaction (I read that
an early radout release was able to do so?).
Be careful with some CAAD apps. Archicad e.g. tends to include all
details in the model, and if you want to render the overview of a large
building, you won't want all the door-locks and furniture in your
model. So try to control the details as needed (use layers etc,
assigning the void modifier can switch off objects, right?).
What applications are you working with?
I use dxf for most architectural models, obj for free-forms (curved
surfaces, smooth surfaces). U used radiance with AutoCAD, ArchiCAD,
FormZ, Vectorworks.
Good luck, CU Lars.
--
Lars O. Grobe
grobe at gmx.net
More information about the Radiance-general
mailing list