How to film a walkthrough for a 3D model
A 3D scan with your phone, no laser scanner involved: you walk through the space once and film while you do. Out of that video comes a walkable 3D model — a Gaussian splat, metric, one unit per metre. This page is how to film so that it works.
The rules are written for rooms, not for single objects. You orbit an object; you walk through a room — every rule here is about the second case. And every rule comes with the reason it exists, measured rather than guessed.
The one rule that decides everything: 0.5×
If your phone has an ultra-wide lens — Apple since the iPhone 11, many mid-range Android phones as well — then film with it, all of the time. Not "when it gets tight", but for the whole walk.
The evidence is one and the same walkthrough, filmed once at 0.5× and once at 1×: at 0.5× the loop closed with 1.47 px of error; at 1× the camera path could not be solved at all. That is not a difference in polish — it is the difference between a result and no result.
The reason is plain: a wide field of view sees more of the room in every single frame. Consecutive frames overlap more, and when you pass a spot again later, the reconstruction recognises it. At 1× you look through a narrower window; through a tele lens, through a keyhole. For rooms, tele is useless.
No ultra-wide on your device? Then film at 1× — but slower, with more overlap, and close the loop without fail. It can work. We would not rely on it.
The rules, in order
Seven of them, 0.5× first. The order is the order of their effect, not the order of your walk.
1. 0.5× — ultra-wide
Never 1× or tele: 1.47 px loop error measured at 0.5×, while the same walkthrough stayed unsolved at 1×.
2. 4K60, HDR and action mode off
Resolution and frame rate high; everything that smooths, stabilises or lifts contrast afterwards, off.
3. Lock exposure and focus, lights on
Set the AE/AF lock before you start — and do not film into the sun or a window.
4. Walk slowly, never just pan
Keep the phone at the same height and walk a curve instead of turning on the spot. A short pause is fine, standing still for minutes is not: it only yields duplicates and pushes the revisits out of the memory of the pose solver.
5. Close the loop
Walk 3–5 m past your starting point so the loop closes unambiguously.
6. Pause briefly in doorways
Show every passage twice — from both sides — and on white, featureless walls keep an edge in the frame.
7. One pass per room, halls in sections
One dedicated pass per room; split large halls into 3–5-minute sections instead of one long take.
Checklist, right before you start
- 0.5× — ultra-wide
- 4K60, HDR and action mode off
- Lock exposure and focus, lights on
- Walk slowly, never just pan
- Close the loop
- Pause briefly in doorways
- One pass per room, halls in sections
The same list on one page, to print and take along: print card.
Frequently asked questions
Does this work on iPhone and on Android?
On both. What matters is not the brand but whether your phone has a 0.5× ultra-wide lens and records 4K at 60 frames per second. iPhones from the 11 onwards do, and so do most mid-range and flagship Android phones.
How long may the video be?
Three to five minutes per section. A flat is done in one go; a hall you split into several sections and upload separately. Longer is not better — a very long video mostly adds more frames of the same places.
Do 360° cameras work?
Not yet. We do not accept raw 360° camera files (.insv, .360), and a full spherical video is not a usable source here either. What does work today: export a flat video with the "Linear" field of view from Insta360 Studio and upload that. Real 360° support is planned, not built — we would rather say so up front.
Do I need a scale marker or a tape measure?
No. The scale comes out of the depth estimate of the walk, and the delivery is metric: one unit is one metre. How accurate that is in a given case is something we are still measuring — until we have a number we can stand behind, we quote none.
White walls, glass and mirrors — do they work?
White, smooth walls are the hardest spot in any room, because there is nothing there to recognise again. Keep an edge, a door frame or the floor in the frame and the reconstruction has something to hold on to. Glass and mirrors stay unreliable: whatever is reflected in them travels with the camera.
How do I get access?
Splatastic is a closed service — access is granted on request. Tell us briefly what you want to capture and what you film with, and we will get back to you by email.
Got a space you want to show as a walkable model?
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