3DS known issues and limitations

      NOTICE: SketchUp 2015 is here! When you look at this Knowledge Center article, be sure to pick "SketchUp 2015" from the red box above to see the 2015 version of that content. If there is no version picker, this content applies to all versions of SketchUp.

This is a Pro only feature.

If you're receiving an error message, SketchUp SDK error: An error has occurred resulting in an invalid output file ... See this forum thread for additional details.

2 Sided Faces

Faces are only visible from the front in some programs while both sides of a face are always visible in SketchUp. These two-sided faces can appear to be missing in other applications if not facing the correct direction. You an manually reorient your faces in SketchUp using the Reverse command or the Orient Faces command to make face directions uniform for a given set of connected geometry.

Additionally, you can use the 'Export two-sided' checkbox to correct this issue.

Flipped Textures

Textures and materials exported with the two-sided/geometry checkbox can appear flipped in certain applications (such as, Maya version 6.0 and 6.5). A 3DS mesh does not store any normal data so normals must be computed by the target system. Some importers might compute the normals incorrectly resulting in the appearance of flipped textures.

Texture Map Names

The 3DS format was designed in an era when DOS-based systems were prevalent. Therefore, 3DS is not capable of storing texture filenames that exceed the 8.3 DOS character limit. This issue can be a limitation to anyone who uses modern OS filename capabilities to manage large, complex projects or file libraries.

SketchUp creates unique names for each texture by adding unique suffixes to file names. For example, a file named 'corrugated metal.jpg' will be described in the 3DS file as 'corrugat.jpg". Any other files that use the same first six letters is truncated and the suffix "01," 02," and so on, are added.

Visibility

Only entities that are currently visible in SketchUp are output to the 3DS file. Rendering display options are not taken into account, which means that faces are output even if SketchUp is in wireframe mode. Faces are not output, however, if they are hidden or if they reside on a layer that is hidden.

Multiple Cameras

3DS format can not store an orthographic camera. This format will be simulated through a perspective camera with a very small field of view or a very large lens length. The eye point will be moved as far away as is possible to yield the same width and height of the projection plane. Certain applications might have problems with a small field of view. For example, Maya does not read the field of view at all and only lets it become as small as 2.5.

Layers

The 3DS format does not support layers. Any layers you assign in SketchUp will be lost. The DWG format might be a better solution if you need layers to export. Alternately, you can export with the 'Color by Layer materials' option enabled, which might allow you to easily select and organize geometry in your model based on SketchUp layers once your model is imported into another application.

Units

SketchUp exports 3DS files at the units specified in the 3DS export options dialog box. This setting can affect the way geometry is described within the 3DS file. For example, a 1 meter cube in SketchUp will export to 3DS with sides of length 1 when units are set to meters. If you change the export units to centimeters, the same cube will export to 3DS with a length of 100.

The 3DS format contains extra information that indicates the original units using a scale factor. This information allows an application that reads 3DS to automatically adjust the size of 3DS models to the correct 'real world' size.

Unfortunately, many applications ignore this extra unit scale information meaning that the centimeter cube imports as 100 times larger than the 1 meter cube, instead of at the same size. Worse, it is not always clear in which unit 3DS files are saved, resulting in considerable trial and error. In these cases, the best work-around is simply to export files at the units setting expected by the 3DS importing application.