Align the sensor in Detect
You can skip this page if you are not running Ouster Detect.
If you are, the sensor has to be aligned in Detect before it is any use to the portal — and before you draw anything.
Align first, then draw zones
Section titled “Align first, then draw zones”Do the alignment before you draw a single zone. That order is the whole point of this page.
Zones are stored in Detect’s world frame: X and Y on the floor, Z up. A zone is a footprint in that frame, and nothing else. So anything that re-mints the frame — aligning the sensor, or re-aligning it later — moves every zone that was drawn in the old one.
Align, confirm the result in the portal, then draw. Doing it the other way round means drawing the same zones twice.
What alignment does
Section titled “What alignment does”In Detect you level the sensor so that the floor is the ground plane and Z points up. In practice that means setting the sensor’s IMU pose so gravity reads as down and the floor sits at Z ≈ 0, then confirming in Detect’s own viewer that the point cloud populates and the floor comes out flat.
The controls belong to Detect, so follow its documentation for where they live and how the pose is entered.
Until this is done, the portal has no usable point cloud for that site. An unaligned sensor is not a partial result you can work around — there is nothing to draw a zone on.
Confirm it in the portal
Section titled “Confirm it in the portal”Open the site’s 3D viewer and look at the floor grid against the returns.
The grid should sit on the visible floor — not floating above it, not buried under it. If the grid is metres off, alignment is not done. Go back to Detect and fix it there before you draw anything, because a zone drawn now is a zone drawn in a frame you are about to replace.
If the sensor moves later
Section titled “If the sensor moves later”Do not re-run alignment on a live site casually. If the sensor was physically moved, you have to re-align — and then you should expect the zones to be wrong, because they were drawn in the frame you just replaced.
The portal does not leave you to discover that on your own. Affected zones show a frame moved state, and the site page offers two actions:
- Check measures how far the world actually moved, against a room reference stored for the site.
- Apply re-registers the zones into the new frame. It is offered only once the check has passed.
Apply is never automatic. Nothing moves your zones without someone deciding to move them.
If the site has no room reference, there is nothing to measure the movement against, and the fix is to redraw the zones. The reference is captured on its own once the sensor has been still and level for a while after setup, so a site aligned and then left alone will have one.
A zone that looks abnormally tall
Section titled “A zone that looks abnormally tall”There is no ground offset to configure, and no Z value to nudge. A zone establishes its own floor from the returns inside its footprint — see Floor Modes & Empty Scans.
So a zone that renders as a tall prism reaching far below the floor is not an offset waiting to be corrected. It is one of two things:
- The site’s frame moved after the zone was drawn. See If the sensor moves later.
- The sensor is not level, so the floor is not the ground plane.
Fix the alignment first. Then Apply, or redraw the zone.
Checklist
Section titled “Checklist”- Mount the sensor rigid. See Mounting the sensors.
- Align it in Detect — level, gravity down, floor at Z ≈ 0.
- Confirm in the portal that the floor grid sits on the floor.
- Draw your zones. See Quick Start.
- If the sensor ever moves: re-align, run Check, then Apply — or redraw the zones.