How to open 3DM file?

Hi!

The result is a 3d house. At the moment I have plans of the house. Those are 3DM files.

  1. I choose the file plans.3DM
  2. and try to open the file in Blender
  3. Blender itself openes BUT I cannot see those plans.

What should I do to make them visible?

Many thanks to helpers.

Kirke

Blender cannot by default open .3dm files. What importer are you using ?

It doesn’t, does it! I had those plans as DGN files. Then they were converted to 3DS.
The sign or picture next to the file name shows blender logo. I am sorry that I do not know where to find which is the importer that I am using. Maybe You could explain?

The sign or picture next to the file name shows blender logo.
Just means you have set the default application to open that file type to be blender. Does not mean it will open. The only file that blender will open are .blend files. Any other file types require an importer addon. The current ones are http://wiki.blender.org/index.php/Extensions:2.6/Py/Scripts#Import-Export_Scripts. Some come already with the blender install, some you will have to download separately. Any addon you will need to activate in the File / User Preferences / Addons panel and then you will get a new option in the File / Import menu.

I need to convert them into other format. Thank You!
Cheers

ONLY

After all this text I have not mentioned that I have opened first floor plans.
Due to the fact that it was not me who did it, I do not know what does this file consists of. Are there only first floor plans or other floors also?

Is it possible that the other floors are right there - I just need to make a tick to somewhere? Where?