Create New Object/Layer from Empty Areas

[MarkN -]

I have a project - a map - which has a ton of background and roads. It turns out that the entire map was created with objects between the roads - in other words, the roads are actually not objects, just remaining spaces not covered by objects. I need to somehow create an object (or group of objects) in a layer that is just the roads. It would seem that I'd need to select all the objects and create an object of the inverse space.

I come from photoshop, where I would just do the selection, invert it, and fill in the space. I have no idea how to create the vector object(s) in illustrator. 

Ideas?

[Ton Frederiks]

If you just want to color the empty space you could create a rectangle, fill it with a color an send it to the back, behind the map.

If you want, you could select both the map and rectangle, click Divide in the Pathfinder panel and ungroup the result.

[MarkN -]

I need to create an object with just the roads. It's not about the "color" of the roads - it's about sending the road layer to a laser cutter so that I can cut the roads as a single element in a layered map. The road layer has to be on top. Thanks!

[Monika Gause · Accepted solution]

You would need to do some cleaning up, but then Ton's method will give you what you want. Make that background rectangle a different color than what you currently have.

Remember that there are the Select > Same items in the menu.

And hope that your computer has enough power to handle the Pathfinder operations.

Also: you won't get strokes paths with the method, but shapes.

[MarkN -]

followup as i work to understand this. 

1. I have created a background layer and filled it with a different color. 

2. do I "unify" the top components into a single element?  I can select them all. 

3. then do I select the unified layer and the background layer? right now I have a ton of differeent elements. 

Thanks- I think I'm almost there - 

[Ton Frederiks · Accepted solution]

Just select both the map and the background rectangle, click Divide in the Pathfinder panel and ungroup the result.

[MarkN -]

Thank you Monika!  This worked!

[MarkN -]

Thank you!  It worked. I sure appreciate it!

[Kurt Gold]

There may be several ways to do that (fore example Live Paint).

Can you share your Illustrator file for inspection?

[MarkN -]

Sure - here is the file. 

[Kurt Gold]

Thanks for the sample file.

No offense intended, but forget about it. That's not a map. That's an incredible mess that probably has been traced automatically.

Do yourself a favour and immediately throw it to the trash can. Your laser cutter would probably wreak havoc anyway. And Illustrator's Live Paint would almost certainly crash if you were using it to create the roads.

Try to get a properly designed map of that region.

[MarkN -]

No offense taken. This is the same map offered on Adobe Stock, iStock and other sites. It turns out that this is the way that many of them are delivered- so while this is not yet a well-designed map, that's the direction I'm trying to go. The only "properly designed map" of LA that I've found has combined the roads into odd groups with everything too identical in width so it is not interesting. Either way, I do need to solve the problem. Open to your suggestions for a source for properly designed maps.

That said, anyone know how to create an object from the "negative" areas of an image?

[Kurt Gold]

In case you have purchased that "map" from Adobe Stock or any other professional vendor, I would definitely complain about it and call for a refund.

Again, that's not a map. It's a horrible disaster and you can clearly see it by zooming in closely. Not only some cleaning up would be necessary, as Monika suggests. Everything in that file would have to be rebuilt, hence my suggestion to just trash it. Remember, you said that you want to use that with a laser cutter!

Do a search for some serious vector map vendors and don't waste your time with that file. Unless you are really looking for that kind of loose woodcut style.

[Monika Gause]

Again, that's not a map. It's a horrible disaster and you can clearly see it by zooming in closely. Not only some cleaning up would be necessary, as Monika suggests. Everything in that file would have to be rebuilt, hence my suggestion to just trash it.

By @Kurt Gold

What I wrote has to be read in the context I put it in. Just to remind you about what I wrote:

"You would need to do some cleaning up, but then Ton's method will give you what you want. "

What Mark wanted: "I need to create an object with just the roads."

And that is what my post is about: Cleaning up so you just get the roads.

I know what a clean map looks like.

[Kurt Gold]

Yes, I know that you know it, Monika.

I think there is no need to clarify it. I was just wondering about the clement suggestion considering the mess that is going to be sent to a laser cutter. Cleaning up in that remarkable file actually means to rebuild the entire construction from the ground up. Or just trash it and get something cleaner.

But in the meantime it turned out that it may just be an experiment. That's ok.

[Kurt Gold]

Mark, please don't get me wrong. Usually, I would have suggested the same or a similar method as Ton did.

But considering your sample file with all those tiny snippets, I still think that you will have a hard time to reasonably do a proper laser cut with that template.

May I ask what material(s) you are going to use to create your product?

[MarkN -]

That's no worries. I really don't know what it will look like till I give it a go. The LA map is pretty boring without a shoreline or anything so I may actually cut it on black acrylic and put it on top of white acrylic and backlight it. I may experiment with engraving instead on wood. If it doesn't work then I'll keep trying other options. Thanks Kurt!

[Kurt Gold]

Thanks for reporting back, Mark.

Probably I was just considering realistic and reasonable cuts from a technical point of view. Certainly I did not consider experimental cuts.

Anyway, good luck with your plans!

[MarkN -]

It's not an "experiment" - it's a wall piece that needs to look great - and is artistic in how this is accomplished. I'm not sure if you have any suggestions for where to get maps  - most sites for map building do not produce vector maps and this is looking way better than any map I've traced. 

[Monika Gause]

You could try if this map is included in the free ArcGIS maps which are a part of this plugin https://www.esri.com/en-us/arcgis/products/maps-for-adobecc/overview

You could try if you could download a map from openstreetmap. But: the roads are just lines, they are not shapes. And it might need a lot of construction work to get it into a shape you want. But since the files are well structured at least the part of deleting what you don't need might work out well.

I don't know what kind of input your laser needs, so you can just try it.

[Kurt Gold]

OK, let's call it artistic now.

Your initial post did not explain your intentions and my assumption was that you just want to get a clean map without any "artistic" impression. Obviously, I was wrong. Sorry for that.

As for your question about vector maps: Please just do a search for "buy professional vector maps". You will then find appropriate vendors.