Calibration Troubleshooting

Cameras that will not connect or stream at all are a Flowbit Capture problem, so see Flowbit Capture - troubleshooting. Physical causes, such as a camera that was knocked, are in Install Your Devices - Troubleshooting.

Your phone cannot open the page

• Check that the phone and the PC are on the same Wi-Fi, with the VPN off.

• If an Address dropdown shows under the QR code, try another IP from it.

• If the phone gets nothing but this PC's own browser opens the app, the firewall is blocking it. See Install and start Flowbit Calibration.

• A third-party security suite such as 360 needs its own allow entry, separate from the Windows firewall rule.

Capture or Sync buttons are greyed out

• Connect the cameras in Flowbit Capture and select Start streaming. Flowbit Capture starts idle, so the buttons stay grey until it is streaming.

• If capture is refused with "saved on its own filesystem", Flowbit Capture is running on another machine. Live capture needs it on this one. Sync still works remotely.

Engine not ready

• Use ↻ Download COLMAP in ⚙ Settings → Reconstruction engine.

• On first run the download takes a few minutes. The header pill reads Engine downloading NN% while it works.

A camera won't register

• Add phone photos taken from that camera's viewpoint, then re-capture and calibrate.

• The same fix applies when a camera's scale or 3D points figure is flagged. Close-up photos of that camera's view give the solver more to work with.

Board not detected

• Match the print to card A's board settings: the dictionary, the Start Id, and the square and marker size in mm.

• Print at 100%, with "fit to page" turned off.

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

"mapper produced no model"

• Re-shoot 20 or more phone photos with generous overlap between them.

Refine kept the coarse result

• Read the reason the app gives. It names what went wrong and what to do. More overlap helps some causes and cannot help others.

• If it says the rig changed shape, the cameras moved relative to one another, which bolted-down cameras cannot do. Check nothing was knocked, then re-capture.

• Check the per-camera depth figures under the result. If sensor noise accounts for most of the pair residual, more scenes will not help.

• If it says the rig changed size, refinement has no absolute ruler, so size belongs to Calibrate. Set Calibration Settings - Metric scale from, where a printed board is the strongest option, and calibrate again.

The Refine button is greyed out

• You changed Metric scale from after this session was calibrated. Select Calibrate again. The reason is shown on the Refine page.

Sync says "No cameras applied"

• The device IDs in the result do not match what Flowbit Capture is streaming. Check Devices in Install and Run Flowbit Capture - Configure Flowbit Capture.

Sync succeeded but the space stays a pile

• Calibration File in config\flowbit-capture.json names a different file than the one Flowbit Calibration wrote, so the result was saved but never applied.

• If every camera draws at the centre instead, toggle Extrinsics: ON in Flowbit Capture. If it stays centred, the rig has no calibration at all.

The space looks doubled or skewed

See Calibrate, Refine, and Sync - If the space looks doubled or skewed for the full procedure.

• Switch Extrinsics off in Flowbit Capture. If the clouds look right there and wrong when fused, the calibration is at fault. If they look wrong in both, the depth is.