From LightWiki

One of the many reasons for new users to get into LightWave is its excellence at architectural visualisation, however most of the major formats for this application are not supported directly by LightWave, or require costly plug-ins. In this tutorial I would like to show you how it can be done natively, or at a minimal cost.

Contents 1 Importing files 1.1 2D 1.2 3D 2 Scale issues 3 Remodelling 4 Editing

Importing files

Before we go further, you should know that neither .DWG nor .max files can be brought into LightWave without external conversion. Even file converters that reckon they can handle .max files can only do so if there is a licence of 3ds max present on the same machine. This means that importing files to LightWave will be restricted to EPS, OBJ, 3DS or DXF. Most architectural CAD packages can export as .3DS or .DXF files, but be aware that you need to be careful on what you export. The safest way is to make sure you only export polygonal entities, no lines, splines, arcs, NURBS, etc.

2D

Floorplans and the like come under the heading 2D files. These can be exported from many applications as straightforward EPSF files that can be read by LightWave. Make sure you save files (or translate them) to version 8 or older of the EPSF standard since post-8 EPS files use PDF for encoding that LightWave does not support. Also, make sure you do not include blends or fills, since they will not be appreciated by Modeler.

3D

The formats that LightWave natively understands are .3DS, .DXF and .OBJ. In all instances, it's best to use the simplest version of each format you can, bearing in mind that

• .3DS only supports triangles, and only up to 64,000 polygons. Materials are reasonably well converted.
• .DXF only supports triangles and polygonal entities, no materials, but layers can be preserved (with LWCAD / Accutrans)
• .OBJ is an old format that supports both triangles, quads and UV maps. Materials are imported using a separate material file, that can be loaded using Mark Greene's free MTL importer plugin : [1].

There are alternatives to the built-in formats.

• LWCAD, offered with LightWave v9.0 and as part of the VizCAD deal offered by NewTek Europe, has a superb DXF importer in v2.1 of the plug-in.
• Accutrans3D [2], a general purpose affordable stand alone 3D object converter and toolset is very adept at converting a large variety of files to the Lightwave format, including DXF, STL, VRML, MA and a large variety of landscape digital elevation data (DEM's)
• Chief Importer by BinaryArts will bring in Chief Architect files http://www.binaryartsinc.com/ChiefImporter.htm
• A variety of packages can export in .STL format and there is a shareware .STL importer for LightWave from Sean Hyde-Moyer http://www.chromecow.com/Lscriptsource.htm

Scale issues

Often CAD packages use an arbitrary scale. LightWave always refers to "1 unit = 1 metre", which means that more often than not your client's models come in way too big or way too small. As long as you know the units that your client uses, conversion is easy to manage. The best way to get a consistent scale is ask your client for an object at a fixed size - a cube at 1m per side is the easiest - and give them one you've made yourself. That way, you'll know what scale multiplier to use when you bring in geometry they send you. There are also a few plugins available to make your life easier concerning scale. Just make sure you have a line or box of a size you know in the object, and use any of the fixed scale plugins available on www.flay.com todo a one-step scale.

Remodelling

Occasionally, especially when the architect you are working with is inexperienced with their CAD package, it can be quicker to remodel from scratch inside Modeler, using the imported model as background if necessary.

Editing

If the file does come in at a strange scale, make sure it's correctly scaled using Absolute Size in the Modify tab and, as is often the case, if you are presented with a mass of triangles, convert those you can to quads (polygons with four points) or higher point polygons using the internal Reduce Polygons tool and the free external plug-in MergeTrigonsX (the author's website is broken, so herewith a link form which you can find the plug-in for your platform: http://www.flay.com/GetDetail.cfm?ID=1394). Learn the habits of the Reduce Polygons command well, as it can both save you hours of work, and wreck the model at the same time. Experiment and save various versions often if you are unfamiliar.

Also, you might do a 'merge points' (shortcut 'm') and a 'unify polygons' operation to clean up the model and use the statistics panel (shortcut 'w') to clean up stray points and 2 point polygons. This usually yields a much cleaner model. Keep in mind though that 2 point polygons might actually be needed to give you the data you need (from 2D cad files for instance).