Working with imported geometry.

How do I know what type it is?

If your supplier sends you a file that imports as loads of triangles, it is a mesh file and in most cases will be difficult to work with. These are most commonly found in STL files and Inventor has limited editing tools for this. 

If you have access to Fusion 360, this program is much better equipped to deal with mesh files and I would recommend that route over Inventor. 

If the file is a solid model, you are good to go, but if it's a surface you may need to do some extra work on it. 

The easiest way to tell the difference is to look in the browser. Solid bodies will appear under the Solid Bodies folder and surfaces in the Surface Bodies folder. A surface will also have an orange icon whilst a solid is usually blue. 

Another way to check is to use the half section view command on the view tab. A solid model with have a mottled texture inside:

Whilst a surface model will be hollow:

How do I make it into a solid?

Solid models are usually much easier to work with, so it is advantageous to convert it to solid. If your file supplier can't give you this, it's time to do it yourself. 

Inventor will automatically turn a fully bounded item into a solid. 

For instance, this cube has a face missing so it displays as a surface.

If we close the face by, for instance using a boundary patch, we can turn it into a solid. 

Applied boundary patch

The cube is still hollow at this stage so we need to use the stitch tool to join it to the other sides. 

When a section view is applied, you can see it is now converted to solid. 

And in the case of the robot:

Repairing Surfaces

If you have a blue exclamation mark, you may need to repair the surfaces first. Errors can occur during the translation process when the part is converted from STEP to Inventor. You can normally work fine with these errors but sometimes they can stop you creating a solid as shown above and can also lead to bigger file sizes. 

Right click the Composite showing the error and choose 'repair bodies.'

You'll be presented with the repair environment: 

I'm not going to go into detail here as there are a lot of tools. But a good place to start is to hit the 'find errors' button.

After selecting the body with an error and clicking OK, Inventor will find the problem areas of the part. 

'Heal Errors' will now be active and clicking this button will make Inventor try it's best to fix the errors. It's not a silver bullet, but you will usually get some benefit from doing this.

Turning Surfaces Opaque

One final tip for importing surface geometry is to make them opaque. 

To make the transparent components opaque, open the file at part level, right click the composite part and turn off translucency. 

The part will now look opaque and appearances can be applied.

To make all imported geometry opaque, tick the box in the application options.