Lining a place up on the satellite map can be done from anywhere. You drag the map until the building sits under the floor plan, then turn the plan until the walls agree. For most places that is the whole job, because the plan arrives already the right size.
It arrives that way because a LiDAR scan is measured. The app knows how big the plan is in real metres, so until build 15 the line-up screen let you move the plan and turn it, and nothing else.
Why the size was left alone
iseeido has two ways to place a map on Earth, and neither of them works out its size. Lining up on the satellite map starts from the scan’s own size. Calibrating on site, by walking with the phone, fits only where the map sits and which way it faces. A phone’s location is far too rough to measure a few percent of a building.
The code is plain about how far a scan can be off: a few percent at most. Anything beyond that, it notes, is a different building.
For the plan that still doesn’t match
Some plans still don’t sit right on their building. So since build 15, the line-up screen has a switch between Turn and Size. Size runs from 50% to 200% of the scan’s own size. The slider works in doublings, so 100% sits in the middle and halving is as far from it as doubling. There are buttons for 1% steps either way, and one that goes straight back to 100%.
The plan grows and shrinks about the crosshair. The point under the crosshair stays where it is, and everything else moves away from it or towards it, in proportion to how far away it is. A door 20 metres from the crosshair moves 5 metres at 125%.
Once the plan isn’t at 100%, the switch says so even while you are turning: it reads “Size 126%” rather than “Size”. A resize can’t go unnoticed. VoiceOver reads the slider as a percentage of the scan’s size, and the step buttons as “1 percent smaller” and “1 percent bigger”. The map’s own screen shows the size too, whenever it isn’t 100%.
What a size moves, and what it never touches
The size is saved with the map’s place on Earth, as ground metres per map metre: 1.04 for a plan lined up at 104%. It changes where every point of the map lands on the planet, the doors you marked included, since they are points on the map.
It never reaches guidance inside the building. Once you are in, iseeido goes by the scan’s own measurements, as it always did.
Calibrating on site keeps the size. The walk is fitted with the map’s points multiplied by it first. Without that, a placement made at 110% and recalibrated as if it were 100% would have its origin moved 1.7 metres.
Maps placed before build 15 have no size saved, so they open at 100%. A size outside 50% to 200% is held to that range. Combining maps, marking doors and sharing a placement all copy the size along with everything else.
- 100%the scan’s own size, where a plan first opens
- 200%the largest a plan can be made, and 50% the smallest
- 1%the smallest step, with a button each way
- 1.7 mhow far a 110% placement’s origin would move if calibration ignored its size
The catch: from above, you see a roof
The satellite map shows the top of the building. The scan saw the rooms, from inside. Between the edge of one and the edge of the other are the outer walls and the eaves, which reach past the rooms.
That is why the Size screen says, in plain words: “Scans are measured to size, so 100% is usually right. The plan should sit just inside the roof’s edge: walls and eaves reach past the rooms.”
The arithmetic
- Ground metres are the size times map metres. At 104%, 10 metres on the plan are 10.4 metres on the ground.
- A point some distance from the crosshair moves that distance times the size less one. At 125%, a door 20 metres out moves 20 × 0.25, which is 5 metres.
- The slider sets the size as a power of two, from one half at the left end to two at the right. Halfway between the middle and the right end is the square root of two, shown as 141%.
- Sizes are whole percentages. The code’s reason: anything finer is finer than the satellite imagery.
What it means with the phone in your hand
For most places, leave Size at 100% and turn. If a plan clearly doesn’t match its building, resize it until it sits just inside the roof’s edge, not on it. Your doors move with the plan, and the size goes wherever the placement goes. Inside the building, guidance still works in the scan’s own metres. The support page covers lining a place up from anywhere.