2.1: Problems with Scale/Size?
The .3DS format is so old that it does not include the unit type (meters, millimeters, feet, inches, etc), so Lumion cannot re-scale it automatically on import.
In Lumion you can rescale using the Scale slider to decrease/increase the model proportionately by up to a factor of 1000.
Option: if there are any problems with the scale then import it to SketchUp. Use the scale option in the 'Import File' dialog window of SketchUp. Then save as an SKP file for import.
2.2: Textures do not import with the model?
Texture file names in the .3DS format must not exceed 8 characters for the old DOS 8.3 file name convention.
This can prevent some textures that are referred to in the material from being different from the file name. So this requires further conversion to work properly.
For example, a material used a texture file name in Windows 10 with the name 'stone_marble.jpg'. When the .3DS model is exported the texture is saved as 'stone_ma.jpg' or 'stone_m~.jpg' or similar depending on the 3D modeling software used to export the model.
You can change the file name back to 'stone_marble.jpg' to match the texture filename reference for the material.
Alternatively, in Lumion, edit the surface using the Material Editor and change the Color Map for the texture by loading the 'stone_marble.jpg' file.
2.3: Why can't you see the model after importing and placing it in your Project?
- The Insertion Point for the Imported Model in Lumion corresponds to 0,0,0 in the 3D application that created the model.
- If a model is far away from the Insertion Point in Lumion, you need to move the model closer to 0,0,0 in the application that created the model, before exporting it to Lumion.
2.4: Why can't you assign a Lumion material to individual surfaces?
- Lumion will always combine surfaces that use the same material in the application that created the model. If you want to assign a Lumion material to a specific surface, you must assign a unique material to that surface in the application that created the model before importing the model.