Collaborative drawing with open source

Thanks to applications like

and

, users of open source have all the tools they need to create stunning digital paintings. It's so good that you can see

in some of your

. And it's getting better all the time: GIMP 2.10 adopted the Mypaint brush engine so users can benefit from Mypaint without even bothering to install the whole application.

But what about collaborative illustration? What do two or more artists do when they want to work together on one piece? What does your work team use when you need to whiteboard during a business meeting? Those are the questions, and the answer is

Drawpile

Nyarlathotep by Sophia Eberhard [IMG]

Drawpile is a drawing application for Linux, Windows, and Mac OS. It's got a respectable brush engine and all the basic editorial tools (selection tools, flips and flops, mirror, and so on) to make it a good freehand digital paint application. But its most powerful feature is that its easy multi-user mode. If you have Drawpile installed, you can host a drawing session either from your computer or on a Drawpile server, allowing other users to join you in your virtual studio. This goes well beyond a screen share session, which would just allow other users to *view* your painting, and it's not a remote desktop with just one cursor. Drawpile enables several users, each with their own brush, to work on the same canvas at the same time, over a network that can span the globe.

Installing Drawpile

If you're using Linux, Drawpile is available as a [Flatpak](LINK TO MY FLATPAK ARTICLE) from

Flathub.org

On Windows and Mac OS, download and install Drawpile from

drawpile.net/download

. On Mac, when you first launch it, you must right-click on its icon and select **Open**, accepting that it hasn't been signed by a registered Apple developer.

Drawing with Drawpile

The Drawpile interface is simple and minimal. Along the right side of the application window are docked palettes, and along the top is a toolbar. Most of the tools available to you are visible: paint brushes, paint buckets, lines, bezier curves, and so on.

For quick access to brushes, Drawpile allows you to assign a unique brush, along with all of its settings (including colour), to the number keys **1** through **5** on your keyboard. It's an efficient and easy way to quickly move between drawing tools, and **6** holds an eraser.

Drawpile also has layers, so you can keep different parts of your painting separate from one another until combining them for your final render. If you're an animator, you can even use Drawpile's onion skin and flipbook features (both available in the **Layer** menu) to do rudimentary frame-by-frame animation. Unlike Krita, Drawpile doesn't feature an

animation timeline

, but it's enough for quick and fun animations.

Custom brushes

Drawpile isn't Krita or Mypaint, so its brush engine is comparatively simple. The preset brushes have the usual properties, though, including:

**opacity** adjusts how your strokes blends with existing paint
**hardness** defines the edges of your stroke
**smudging** allows existing strokes to be affected by your brush
**colour pickup** allows your paint to pick up colour from existing strokes
**spacing** controls how often the full brush cursor is sampled during a stroke

Most of these are pressure sensitive, so if you're using a drawing tablet (Wacom, for instance), then your brush strokes are dynamic depending upon pen pressure. The tablet support is borrowed from Krita, in fact, and it makes a big difference (although it's probably overkill for mock-ups or whiteboarding sessions).

When you find a brush setting you like, you can add it to your brush set so you can use it again later. To add a brush, click the **Menu** button in the top right corner of the docked **Brushes** palette and select **Add brush**.

Adding a brush in Drawpile [IMG]

If the **Brushes** palette isn't visible, go to the **View** menu in the top menu bar and select **Brushes** from the **Docks** submenu.

Collaborative drawing

To start a shared drawing session, go to the **Session** menu and click either **Host** to host a session or **Join** to join in on an existing one.

If you're joining a session, you need to know either the URL or the IP address of the session you're trying to join. An URL is like a website address, such as syntheticdreams.net/listing. An IP address is the numerical version of an URL, such as 93.184.216.34. Some IP addresses are internal to your building, while others exist out on the Internet. To join a session, you need the URL or the IP address of the session. If you haven't been invited to a drawing session, you might be able to find a public group on

drawpile.net/communities

If you're hosting a session, give your session a title and an optional password (or leave it blank to allow anyone in). In the **Server** section, set whether you're hosting the session from your computer or from someone else's server. You can host sessions on `pub.drawpile.net` for free, but all of your data is sent out to the Internet in that case, which could affect performance. If you have a good Internet connection, the lag is negligible, but if you're not confident in your Internet speed, or else there's no reason to go out to the Internet because your collaborators are in the same building as you, then you can host your session locally.

If you host locally, you must provide your IP address or computer name (ending in `.local`) to your collaborators so their Drawpile apps can find your computer. You can find your computer name in the **Sharing** preferences of the GNOME desktop, if you're on Linux:

[IMG]

You must enable Remote Login, and possibly adjust your

firewall settings

to allow other users to get through.

On Mac OS and Windows, you may or may not be running a firewall, and you may need to provide additional sharing permissions in your control panel or system settings.

Drawing with friends

Open source has always been about sharing. Drawpile is not only software you can share with your friends and colleagues, it's software that allows you to work with them in a fun and creative way. Try Drawpile for your next project or exciting boardroom meeting!