Capture the Space

Before you start

Before you start, confirm the app reads Engine ready, every camera is streaming in Flowbit Capture, and your phone is on the same Wi-Fi with the VPN off, see Install and start Flowbit Calibration.

Choose a world origin

	Use a camera as the reference	Use the marker as the reference
World map
Anchor of the calibration	One of the cameras. Pick which one in Calibrate, or leave it on auto	The printed marker, where you put it on the floor
Print the marker	No	Yes

Which should I choose?

Use the marker for the most accurate result. The board is a ruler of known size, so it gives the strongest metric scale, and the origin lands where you put it. The cost is one extra step: printing and placing the board.

Use a camera to start straight away. Nothing to print, so you go directly to the phone sweep. The origin lands at the reference camera, and scale comes from the cameras' own depth.

NOTE

For where each choice puts the origin, see Coordinate systems. For what each choice does to the size of the result, see Calibration Settings - Metric scale from. If you chose a camera, skip to Capture the Space - Take the phone sweep.

Print and place the calibration board

1. Select ⬇ Download board PDF on Card A.

2. Print it at 100% actual size, with "fit to page" turned off.

3. Measure one square against a ruler to confirm the print scale.

4. Check that the card's settings match the sheet you printed: the dictionary, the Start Id, and the square and marker size in mm.

5. Lay the board flat and face-up on the floor, in view of at least one camera. If the app cannot find the marker when you select Calibrate, the run stops immediately with an error.

   NOTE

   Leave the board in place for both the phone sweep and the camera trigger.

Take the phone sweep

1. Scan the QR code on card B with your phone.

   If several addresses are detected, pick a reachable one from the Address dropdown under the QR.

   

2. Shoot 20 or more overlapping photos of the space on the main wide lens, with no zoom.

   Select Take Photo for one shot at a time, or Gallery to upload a batch you already took with the camera app. Wrong-lens and HEIC photos are rejected with a retake message.

   

3. Include shots taken from near each camera's viewpoint.

4. Keep the page open while the photos upload. You can carry on walking.

   

Verify that you have enough photos

Check that the badge on Card B reads ENOUGH PHOTOS. More coverage is fine.

Capture the fixed-camera frames

Pick a mode at the top of Card C: Trigger live or Load a folder.

Trigger live

1. Check the camera chips at the top of the card. There is one per streaming camera.

   If there are none, connect and stream the cameras in Flowbit Capture. There is nothing to connect or refresh here.

2. Confirm the space is in the same arrangement as during the phone sweep.

3. Select ⚡ Trigger cameras.

   The first captured frame becomes the ★ Calibration frame. To use a different one, select Set for calibration on it.

   

   NOTE

   If Flowbit Capture runs on another PC, set its host and port in ⚙ Settings → Connections. Only Sync works from there.

Load a folder

1. Select Load folder… and pick the folder. It can be a single capture, a flat folder of captures, or a whole captures/ tree.

2. Review the scene grouping the app proposes.

   It groups frames by comparing the images, so folder names and capture times are ignored.

3. Select ✓ Use these scenes to import, or Dismiss to discard.

   If no frame is tagged yet, the first one becomes the calibration frame.

What the scene cards show

Each scene appears as Scene N · M frames, listing its frame timestamps above that scene's camera images.

• 🗑 deletes the scene.

• The card holding the ★ shows a Calibration frame pill. The others offer Set for calibration.

• Only the newest card offers ⚡ Add frame. Older cards read closed.

Add scenes to improve Refine

This step is optional, but strongly recommended.

1. Move objects around the space. Do not move the cameras.

   Use tall, solid objects, roughly knee to chest height. Boxes, chairs, bins, a stepladder or a tripod all work. Each pair of cameras needs to see at least two of them, at different distances.

   NOTE

   Sheets of paper, posters and mats lying on the floor do not count.

   They sit in the same plane as the floor, so to a depth camera they add nothing the floor did not already provide. Refine needs the floor broken up to work out where the cameras are along it.

2. Select ＋ New scene and confirm. The cameras trigger straight away, giving the new scene its first frame.

   

3. Select ⚡ Add frame for any further frames of that arrangement.

4. Repeat until you have two or more scenes. Do not re-shoot the phone photos.

   

The on-site work is done. Now please go to Calibrate, Refine, and Sync.