Research · Spatial Computing · AR/XR · Gaussian Splatting · Research
Persistent AR: Stateful Spatial Worlds, Built on a Phone
What would it take for anyone to build a spatial world on a phone and find it exactly where they left it? Inside Portals' approach to persistent augmented reality: creation without 3D skills, scenes stored as intent rather than geometry, and real-time Gaussian splats on edge devices.
· Ryan Brant
Most augmented reality is ephemeral. You open an app, place something, and the moment you close it the world forgets. For spatial computing to become a medium people actually build in, AR content has to persist: saved, shared, and waiting exactly where you left it.
That is the question behind Portals, H3M's spatial creation app: what would it take for anyone to build a spatial world on a phone, and find it exactly where they left it?
The constraint is the device itself. A phone has hard compute and thermal limits, and there is no guarantee of a network. Whatever we build has to run on the edge.
Creation without 3D skills
The first barrier to spatial creation is skill. Traditional 3D tools assume you can model, rig, and light. Portals assumes you can speak, paint, and place.
On an iPhone, creators work with spatial brushes, particles, Gaussian-splat worlds, and templates. You can paint light trails through your bedroom, drop a splat environment into a room, or start from a template and change it with your voice.
Store the intent, not the geometry
The deeper problem is what a saved world actually is. Storing raw geometry makes scenes heavy, hard to edit, and tied to the device that made them.
Portals takes a different approach. XRAI stores a scene as the rules that produced it, so the file is compact, portable, and replayable. The same small file rebuilds the same scene, for you or for anyone you share it with. XRAI is Ryan Brant's concept, co-developed with James Tunick.
Persistence
A Portals scene saves as one file, placed relative to an anchor you tap, and reopens intact. Open it somewhere else and it unfolds around a new anchor. Share it and it opens the same way for someone else. GPS puts scenes on the map, so worlds can live in real places.
Real-time craft on mobile
Persistence only matters if the worlds are worth returning to. Portals is designed to run Gaussian-splat environments, live VFX, and volumetric performers on a phone, which is the same visual vocabulary as high-end immersive production, brought to an edge device.
In the field, Portals experiences include world-scale anchoring of building-sized structures, portal doorways that join a real shop floor to a full AR world, animated characters with particle effects, live puppeteering, and location-based gameplay.
Where it stands
The work behind Portals is published as a CVPR 2026 workshop paper on persistent, editable 4D world models (Tunick, Brant, Pennock, Kasowski), and the approach is patent pending as Systems and Methods for Intent-Based Persistent Spatial World Models on Edge Devices. Portals is currently in beta.
Store the intent, not the output. Then a world can travel across sessions, devices, and people.
That principle is what turns augmented reality from a moment into a place.