Merging hollow meshes for 3D Printing

[drumrboy44]

Ok, this is part of a project to 3D print models of cities using data extracted from public sources.  I have extracted the model data for cities, but cannot get models that will print correctly.  From the attached file, you will see that I created a simple standard primitive rectangular base, but there are also sorts of holes in the meshes of the cities. Do you 3DS wizards know any way to :

1) combine the solid rectangular primitive so that it will be solid through the meshes that it intersects; and/or 

2) fill the sometimes hollow 3d building models so that I can print them (regardless of the interiors)

Any help would be GREATLY appreciated!

-Drumrboy44

Below are links to the .max and .dwf files (both were too big for uploading)

city models

[PROH]

Hi Drumrboy44

Took a look at your 3ds file. First of all, it's is not because of the files size that you couldn't attach them. You need to zip them. You didn't upload a *.max file, instead you uploaded a *.3ds file. That's not the same.

To make things printable, they normally need to "solid". In Max that means a "waterthight mesh" or a "Body-element". In Max the same applies to everything that is going to be exported to *.stl. Your model (3ds version) containes lots of open meshes, single sided objects and meshes with holes. There's no automatic way to clean these things up, you simply need to do some serious modeling work.

As for how to "combine" the buildings with the ground, I believe it should be enough to make shure there is an overlap between them - meaning that the buildings should proceed into the ground, instead of "stopping" right above the ground. If you really need to make the whole model into one clean solid, then export the model to AutoCAD (after cleaning it up), convert the waterthight meshes to Solids and then use the Boolean Union command.

Hope it helps.

[samab]

There is an "STL Check" modifier you can apply to an object which will highlight any problems with the mesh.