This Converter reads and writes object and scene files for NewTek's LightWave modeling and animation program. It adds two entries to the conversion lists:

LightWave object *.lw;*.lwo
LightWave scene *.scn;*.lws

LightWave objects are given the extension ".lwo" although LightWave does not require this addition to the filename.

Geometry
Each polygon can have between one and 65,535 points. LightWave renders a polygon with just one point as a dot. Polygons with just two points (like a line) are always shown as a line. Dots and lines are always visible, regardless of distance.

Orientation of polygons is important to LightWave. Normally, LightWave polygons are only visible from one side, as determined by the order in which the polygon's points are listed. Looking at the polygon from the outward visible side, points are listed in a counter-clockwise direction around the polygon, starting from any convex point.

When reading LightWave objects, detail polygons are translated as ordinary polygons. Note that these detail polygons might not render correctly unless they are elevated slightly above the plane of the parent polygon. Detail polygons are not created on export.

LightWave has a loosely-enforced standard for object dimensions, with value 1.0 meaning one meter.

Material attributes
LightWave and Interchange have similar methods for representing material attributes.

When reading LightWave objects with texture-mapped materials, Interchange will create per-point UV values that can be passed to other formats.

However, LightWave doesn't support the explicit per-point UV values used in most other 3D programs. When Interchange exports a texture-mapped material, a default spherical map will be added to the LightWave surface definition. This sets the correspondence to the proper texture bitmap, but may not reflect the correct mapping.

LightWave scene files
LightWave objects are a single object in a single file. LightWave uses scene files to represent hierarchies, as well as settings for the camera, lights, etc. Scene files are ASCII text and can be edited in a text editor.

This Converter reads LightWave scene files, loading all the objects and translating the scene to other formats. Translating a scene preserves the hierarchy if the destination format supports it.

When "LightWave scene" is the destination format, Interchange creates a scene file. The objects are converted to separate LightWave objects, each referenced in the scene file.

If you want to share a scene and its objects with someone, be sure to send them all the objects as well as the scene file, and that you've specified the object filenames in a portable way, as described below.

Note that this Converter only exchanges the geometry information of scenes. Cameras, lights, and other scene-specific details are not translated.

Options dialog

Import section
Content directory lets you set the location of your LightWave content directory. This aids in the loading and saving of objects and images from LightWave scenes.

If Don't load scenes in batch conversion is set, then LightWave scene files will not be recognized. This makes it easier to select all files for conversion in a directory containing both scene and object files, and to only convert the object files and ignore the scenes.

Export section
Make DOS filenames sets whether sub-object names will be forced to conform with MS-DOS-style "8.3" filenames when writing out scene files.

Double-sided surfaces sets whether LightWave surfaces will be forced to have the double-sided surface attribute, eliminating the need to properly orient all polygons in an object.

Center objects determines whether exported LightWave objects (not in scene files) are re-centered to reflect their center of rotation. Un-check this if you want all objects to retain their original positions when manually merging objects into a single scene.

Max 64K polygons per object enforces the limit of 65,530 polygons per LightWave object file found in earlier versions of LightWave.

Make surface name from object and material names creates Lightwave surfaces with expanded names that make it easier to distinguish materials used on specific objects.

If Flip normals of polygons is set, the orientation of polygons will be reversed.

If Max polygon sides is set, then polygons with more than the given number of sides will be reduced to polygons and triangles in the same shape as the original polygon. LightWave 1.0 and 2.0 recommended using less than 80 points per polygon, even though they allowed more than 200 points per polygon. In these versions, polygons with a greater number of points cause bugs. LightWave 3.0 and beyond allow up to 65,535 points per polygon.

Make point polygons and Make line polygons control whether Interchange will search for and write out any one- or two-point polygons.

Scenes section
The Add light to scene works around a bug in the Amiga version of LightWave 3.5 that required at least one light in a scene file. If this is not set, then no lights are added to the scene file.

Export to Objects and Scenes directories means that Objects and Scenes directories will be created in the destination directory. All ".lwo" object files will be placed in the Objects directory and the ".lws" scene file will be in the Scenes directory. This matches the way LightWave naturally stores object and scene files.

Make scene in its own directory creates a new directory for the scene. This directory name is derived from the base filename of the original object. This becomes the new destination directory for purposes of the above Export to Objects and Scenes directories option.

Common Questions

When I ask to convert a scene, Interchange reports it can't open some of the object files.
Be sure all the objects are present in the locations described in the scene file, and that you have set the "Content directory" option to your LightWave installation directory. Verify the scene file by loading it into a text editor, and be sure all object files are present in the proper directories. Objects are listed in scene files with either relative or absolute paths and filenames.

When I load objects into LightWave, it resets all my surfaces.
Be aware of how LightWave will change surface definitions when you load objects. If you load an object file with the same surface names as any surfaces already present in LightWave, then the newly loaded surface definitions will replace the old surfaces. To prevent this collision and the replacement of the surfaces you've already defined, be sure to rename any existing surfaces before loading a new object that might have similar surface names.

For example, to insure that each object retains its own unique surface names as you load it into LightWave, rename the new surfaces after you load them. Change each new surface to something more descriptive that reminds you of both the object and the surface. LightWave is sensitive to "case" in surface names. "BLUE" and "blue" and "Blue" are considered different surfaces.

In early versions of LightWave, you can completely erase the surface name leaving a null, empty name. If Interchange encounters a null surface name when reading an object, a unique surface name will be created instead, such as "(null surface 2)".

Background
LightWave is made by:
NewTek, Inc.
1200 SW Executive Drive
Topeka, KA 66615
(913) 228-8000
(913) 228-8001 FAX
www.newtek.com