Picture: Liz Edwards
An artist enters Metropolis 17 with a VR headset and paints scenes from the sport world utilizing one other VR app. How does this work?
Artist Liz Edwards has arrange store in Russell’s lair. Armed with an easel, paintbrush and palette, she paints a portrait of the underground fighter absorbed in his pc.
Does Half-Life: Alyx help digital oil portray? No, by no means. Portray is made attainable by one other VR program that’s introduced into the world of Half-Life: Alyx as an utility overlay: the oil portray simulation Vermillion. So the portray scene reveals a VR world that’s prolonged by one other VR utility in AR trend.
The Vermillion overlay will not be restricted to Half-Life: Alyx and can be utilized in different SteamVR apps as properly. “It’s completely wild with the ability to casually oil paint inside any SteamVR recreation,” Edwards writes.
Beta model now out there
Vermillion creator Thomas van den Berge programmed the import characteristic in lower than every week out of curiosity whether or not it was attainable.
“It’s an overlay that runs on high of SteamVR and could be interacted with individually to the sport. I’ve solely seen 2D home windows earlier than,” Van den Berge wrote on Twitter.
And what occurs in the event you get attacked by Mix or Headcrabs in the course of your contemplative portray session? Don’t fear: In line with Van den Berge, you possibly can at all times change again to the sport’s controls to combat off the invaders.
If you wish to check out the beta characteristic, you’ll have to allow it within the VR app’s launch choices. Digital portray in VR worlds ought to work easily with the HTC Vive and Valve Index, however there should be stuttering in Quest. Van den Berge is engaged on this.
A glimpse into the way forward for the metaverse
The experiment reveals the untapped potential of the metaverse idea.
What in the event you couldn’t solely transfer avatars and objects from one digital world to a different, but in addition open VR purposes in one other? Why ought to a digital world be a last product moderately than infinitely expandable?
The probabilities of extending VR worlds, combining and nesting VR purposes are laborious to think about right now. Van den Berge’s attention-grabbing experiment affords a glimpse into such a future.
How the Vermillion overlay works
Thomas van den Berge defined to me how the expertise works. See his reply under.
A tiny little bit of technical background on how rendering in VR works first: the sport world is rendered for every eye, identical to it might be rendered as soon as for a flat display screen recreation. After this nevertheless, the output for every eye is warped to counteract the distortion of the lenses. This stretches the rendered picture, making it blurry. Because of this it’s essential to render at the next decision than the quantity of pixels in your headset to get a crisp picture, or why standalone VR video games that don’t have the efficiency funds to do that look blurrier than video games on PC.
VR runtimes have the flexibility to overlay textures instantly onto the ultimate picture that’s despatched to the headset’s shows, with out having to be distorted to match the lenses. They should be a selected form: a rectangle, a cylinder, or a 360 panorama. That is the expertise behind the very crisp menu panels you see once you open your VR dashboard. Overlays are additionally utilized by video games to get a extra legible in-game menu.
With OpenVR, the VR runtime behind SteamVR, you possibly can go a step additional: you can begin an utility purely as an overlay moderately than as a recreation, with the intention to have each a recreation and a number of overlay purposes operating concurrently. This has been used up to now by purposes equivalent to LIV or Desktop+ to point out supplemental data in VR, on floating rectangular overlays. OpenVR additionally helps capturing inputs in overlays, with the intention to override the inputs from the sport, stopping recreation actions from taking place once you really need to be interacting with the overlay.
With Vermillion nevertheless, I wanted to point out a complete 3D scene as an overlay, not only a floating panel. The overlay characteristic has virtually no documentation, and from what I learn on Twitter, there wasn’t a technique to get a 3D overlay operating easily. I used to be about to surrender, when somebody talked about Joe Ludwig to me. He’s one of many builders at Valve behind SteamVR, who occurred to have created Aardvark XR in 2020. Aardvark is an overlay utility that pulls a full 3D scene, a person extensible platform for creating spatial widgets. Aardvark is open supply, and whereas it’s a local C++ utility and Vermillion is made with Unity, it had all of the parts I wanted to grasp the right way to create a 3D overlay scene.
It leverages the 360 panorama overlay mode by warping the overlay’s eye outputs to a stereo panorama. The following problem lies in making the digital camera place and rotation match that of the sport that’s being rendered. The overlay is totally separate from the sport, and has no notion of the place the in-game digital camera is positioned. If there’s a mismatch between the digital camera motion in-game and within the overlay, the overlay seems to be “juddering” or lagging behind. As quickly because the framerate of the overlay doesn’t match that of the sport, this turns into very obvious.
To date I’ve been capable of get a really steady end result on SteamVR headsets (equivalent to Vive and Index), utterly promoting the phantasm that the Vermillion easel is a part of the sport. Sadly plainly the extra steps required for gaming on Quest over (Air) Hyperlink trigger a disturbance, as there’s nonetheless judder on there presently. Fingers crossed I can get this sorted out!