Google’s Tilt Brush is one of the best VR painting apps for the Oculus Rift and HTC Vive. Since its release in 2016, artists have drawn magnificent ships, jaw-dropping mountain ranges and imaginative fight scenes in immersive 3D. Most of the app’s brushes, however, mimic the real world with flat, ribbon-like strokes. For years, you’ve had to move around and paint, or ‘color in’ every surface of a 3D object like a cube or cone.
It was pretty time consuming. Thankfully, the team behind Tilt Brush noticed and introduced a solution, called the hull brush, toward the end of June.
The new tool allows you to paint volumetrically. Normally, the app follows your movements in mid-air and creates a series of control points. These are supplemented with secondary points and then converted into colorful brush strokes. The hull brush, however, uses the control points to create a 3D mesh. The outermost points dictate the final size and shape, which for now has to be convex (curving outward, rather than inward). “The simplest way to think of a convex hull is as if you were ‘gift wrapping’ the points with geometry,” Jeremy Cowles, the technology lead for Tilt Brush explained.
In practice, you simply move the Rift or Vive controller through 3D space and watch as an abstract object is ‘filled in.’ With a single gesture, you can create a slab-like blob that is clearly visible from every angle. Now, people are embracing the hull brush as a way to quickly build characters and scenes. Steve Teeple, a concept artist who has worked with Marvel, Google and The Weeknd, among others, used the tool to create a dark and mysterious astronaut on June 29th. It’s a wonderful creation that could easily pass for some new Mass Effect or Destiny artwork.
“It’s a bit of a game changer in the Tilt Brush world,” he explained, “because while technically all the brushes create geometry of some kind when exported, usually a flat plane, it’s the first real 3D like brush we’ve seen added to the app.”
Steve Teeple: Visitor
Roscoe Studio: Woman by the Pool
The hull brush was made in response to user feedback (including a Pixar employee) who wanted a simpler way to create 3D objects. “If you’ve ever tried to create a solid sphere Tilt Brush without using any guides, the need is painfully obvious,” Cowles said. At first, the developer experimented with concave (inward facing curves) hulls because they were easier to implement “and mathematically well defined.” The user experience was unnatural, and for a while, Cowles considered abandoning the idea. He showed the team a couple of prototypes, though, which led to the convex-based tool available today.
“It quickly became clear that it was worth keeping,” he said.
Artists are profiting from that decision. Cesar ‘3Dominus‘ Ortega, for instance, used