Here's how I would do it:
I have a single building made up of three polygons that I would like to be a single 3D feature when I convert it to a collada file.
- I add a text field called "Description" to the polygon multipatch attribute table.
- I select all three records, use the field calculator to change their "Description" to "Building1".
- I open up the "Multipatch To Collada" tool, fill in the "Input" and "Output" information and then, where it asks for the "Use Field Name", choose "Description" from the dropdown list.
- Click "OK".
From my experience, when I open the collada file in SketchUp the three polygons have now become one file. If I were to look in the folder I designated as the output location and I saw one file called "Building1.dae" then I know it worked.
Now, let's suppose that you have a number of features in the multipatch file with a variety of "Description" values (i.e., Building1, Building2, Building3). When you run the conversion to collada you will have one .dae file for each "Description" (i.e., Building1.dae, Building2.dae, Building3.dae).
Hope this helps.
Julie
