Learning how to VR with Tilt Brush, HTC Vive’s killer app

History shows that if you want to impress the world with a brand-new way of computing, you better pack in some painting software. MacPaint made us believe in the Macintosh's GUI and mouse. Educational, art-driven software like Hypercard, Hyperstudio, and Kid Pix dominated school computer labs for years. Even the pre-installed sensation that is Microsoft Paint gets mileage to this day, if mostly for comical effect.

These applications weren't just fun to mess with, they also made it fun to learn how to use a mouse—that thing you use pretty much every day. That, above all else, is why Tilt Brush can safely be called the HTC Vive's killer app. It serves the same educational role for motion-tracked controllers.

Like Ars Gaming Editor Kyle Orland said in his Vive hardware review, we've been teased with motion-based systems like Nintendo's Wii and Xbox's Kinect for years. The Vive doesn't tease. Its mix of a headset, two precisely tracked handheld controllers, and two tracking beacons delivers a convincing method for accurately tracing patterns in 3D space. This is a significant, 3D step-up from the mouse of old, so we'd best get to painting with it.

Rather than offer a straight-up review of Tilt Brush (which comes as a free pack-in with every HTC Vive pre-order), I'm going to chronicle what it was like to learn the app's ins and outs. It's time to tap into the little second-grader in me—the one who flipped his lid in the '80s after his first computer lab experience.

Geez, there's a whole third dimension right over there

Having watched a lot of newcomers test my copy of Tilt Brush over the past month, I still crack up every time new users do the exact same thing I did in my first session. With the headset on and Tilt Brush's default, dark-canvas zone loaded, everyone defaults to drawing a two-dimensional image. It's as if the empty space in front of them is a giant, flat sheet of paper.

Your right-hand wand defaults as your paint brush (you can swap this if you're a leftie), and the app starts you off with a simple, shiny, blue brushstroke. Perhaps it's because new users are unfamiliar with the deeper possibilities of VR, or perhaps it's because the brushstroke looks like a marker as opposed to some sort of clay, putty, or other sculpture-friendly material. Whatever the reason, new Tilt-Brushers always start by drawing flat shapes or writing words.

Eventually, the mental gear will turn over. In my first use at a trade show demo, that moment happened once I stepped to the side and found that the thing I'd drawn looked very strange from an oblique angle. As I kept walking around my so-called art, I was amazed at how different my 2D creation looked in 3D. My brush strokes were hanging in mid-air exactly where I'd placed them.

This changes things.

The next time I got a chance to stick my face into an HTC Vive, I demanded Tilt Brush be loaded—I'm sure I did so rudely, looking to Veruca Salt as the ultimate "gimme gimme gimme" role model. I was told I only had a few minutes. Fine, I thought. I drew a bicycle.

With little time to spare, I didn't play with the giant "palette" block of brush, color, and design options hiding in my left hand. Instead, I focused on creating basic, readable forms, as if I were the first caveman to scrawl on a VR wall. Handlebars were my framing form, and from there, I could draw other parts perpendicular, parallel, and in proportion, including the front wheel, back wheel, triangle base, pedals, gears, and spokes. It was all drawn with great haste, but once it was finished, I could walk all the way around this thing and see it like a real bike. This was my bike. (With a moment to spare, I scribbled in a basket on the back and a Trader Joe's grocery back. My bike!)

Mostly, I wanted to prove to myself that this was easy to do. I'm an adequate sketch artist, but I'm not a sculptor by any means. Yet there I was, paint-sculpting an object faster than a balloon artist could make a puppy. I retold this story time and time again at parties, surely wearing my friends out—"Guys! In VR, you can make a bike"—and started really believing in my future Tilt Brush prowess.

Boxing day

The trouble began once I actually had a Vive in my home.

The time constraints of past experiences were now gone, as was the thrill of showing off my nascent sculpting skills to whoever was manning that day's demo booth. ("Yeah, I consider myself a Tilt Brush expert. I've used it three times already.")

Though I had history with the app, I'd never really considered its limitations and missing features until I finally had more time to plot something out. I soon had to face the app's biggest quirk: its reliance on flat brush strokes.

Tilt Brush offers 24 brush stroke types in all, and some of them are clearly meant to punctuate your creations' general forms, including smoke and falling snow. Most of them change the intensity, shading, and texture effects of a standard brush stroke, meaning your next stroke could look like a lit-up wire, a shiny piece of paper, a messy splot of paint, and more.

I started by drawing a box. That's easy enough, right? Well, not exactly. Tilt Brush doesn't offer 3D shapes, so the only way to make a box is by drawing its outline. Thankfully, Tilt Brush's "straight line" lets painters draw directly from a start point to an end point anywhere in 3D space, using any available paint brush style. (In one nice touch, you can draw a perfectly angled line up and down the X or Y axis by moving your line guide until its indicator changes from blue to orange.)

Once I'd completed the outline, however, there was the matter of filling it in. None of the strokes really offer a way to fully coat the side of a cube so that it seals up like the material of a box. You can use the paper and duct tape brush strokes to approximate this idea, but you still have to perfectly layer a few flat strokes that are drawn at just the right angles and positions. Worse, while you can very easily shrink or grow the brush stroke size by gliding your finger on the HTC Vive's circle pad, you can't overpaint a blocked-out square and then manually delete any overflow. In its current iteration, Tilt Brush's erase function deletes full lines, not individually chosen chunks of a given line.

I was pretty frustrated by this combination of factors at first. How the heck do I make 3D things with nothing more than 2D linework? Then I went back into Tilt Brush's "gallery," which contains about a dozen creations by other talented people who used the app's early beta. One of these, drawn by former Disney animator Glen Keane, fills the "canvas" (as in, the empty sculpting room) with over 20 human forms. These forms felt totally alive, even though they weren't fully blocked out and filled in. Instead, Keane used deliberate line work to specify obvious parts of the body—heads, arms, breasts, butts, and legs—and then used color and more abstract line work to suggest the rest of the forms and their motion. This looked like a giant dance, and the abstract construction and bold color choices made it feel truly alive.

Seeing this creation convinced me that Tilt Brush's lack of major 3D forms (spheres, cubes, etc.) was wholly intentional. Up until now, the domain of "3D construction" has been dominated by game creators and sandbox-game players who build virtual worlds one polygon or pre-defined structure at a time. Tilt Brush, hand-in-virtual-hand with the HTC Vive, is unlocking this kind of functionality for a whole new market, and they've done a very keen thing in simultaneously giving the games side of the audience something astounding, refreshing, and confusing.