Digital Painting On An IPad With Real Brushes

December 10, 2021 by Lewin Day 8 Comments

Drawing tablets are a great way to make digital art, and iPads and other tablets are similarly popular in this area. However, they all typically involve using some sort of special stylus for input. [Richard Greene] developed another method, with Light Strokes for the iPad letting one “paint” with real paint brushes instead!

The system uses a Fresnel prism in view of the iPad’s camera. This allows the camera to see only the parts of a paint brush, sponge, or other implement, as they make contact with the surface of the prism itself. This is via the principle known as total internal reflection.

Thus, simply wetting a paintbrush, sponge, or even a finger, allows one to paint quite authentically on the surface of the prism. The corresponding Light Strokes app on the iPad turns this into the pretty pixels of your creation. The app also allows one to experiment with all manner of fancy brush effects, too.

The build requires some finesse, with the lamination of the special Fresnel film onto glass using liquid optically clear adhesive, or LOCA. A series of mirrors are then assembled in an enclosure, allowing the iPad to be mounted with the camera having a good view of the glass painting area.

The project takes advantage of a simple physical effect in order to create a great artistic tool. Alternatively, if you prefer to draw directly, consider whipping up your own screen-based drawing tablet. Video after the break.

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Improved Graphics-to-Drawing Tablet Conversion

May 7, 2021 by Chris Lott 7 Comments

[Akaki Kuumeri] had an old Wacom Intuos digitizing graphics tablet collecting dust, and figured out how to non-destructively transform it into a drawing tablet. He was inspired by an old Hackaday post of a similar hack, but it required literally hacking a big hole into your Wacom tablet. Not wanting to permanently ruin the Wacom tablet, [Akaki] instead designed a 3D printed frame which he holds in place with a pair of straps. The design files are available on Thingiverse. He names the project, incorrectly as he later points out, WacomOLED (it rhymes with guacamole, we think).

As for the screen, he buys an old third-generation iPad and removes its Retina display panel and the foil backing, which would otherwise block the stylus’s connection to the tablet. Toss in an HDMI driver board to connect the display to your computer, and presto — you have made your own a drawing tablet. Even if you don’t need a drawing tablet, [Akaki]’s hack is still interesting, if only to remind us that we can put custom HDMI displays into any project for $65 using this technique.

In the end, [Akaki] notes that unless you already have a non-graphical digitizing tablet laying around, it’s probably cheaper to just buy a iPad. This is not [Akaki]’s first go at user input devices — we wrote about his Smash Brothers game controller and flight controller yoke project last year.

Do any of you use a graphics tablet in your day to day workflow? Let us know in the comments below.

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Back To The Drawing Board

January 28, 2016 by Al Williams 26 Comments

Ever try signing your name with a mouse or a trackball? Not so easy. You could buy a graphics tablet with a pen. [Rahul Ramakrishnan] has a different approach. He took two 10-turn pots, and attached some strings and a washer. A pencil goes through the washer, and a BeagleBone Black reads the pots to determine what it is drawing on the paper. A couple of retractable badge lanyards keep tension on the string.

This ingenious design would be easy enough to replicate with any microcontroller that can read the two pots. The only awkward part is the need to press a button down when you want the device to treat the pencil as down (see the video below). It would probably be easy to rig up some switch on the pencil to make operation a little smoother.

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