Scanning surroundings, do I need a target?

[pikasi]

I need to scan surroundings for film and photo shoots. Collaborators are using the point cloud to roughly measure the space and decide equipment placement.

Do I need to photograph a target print of a specific size to assure accurate placement? I usually photograph a 2 sqm zone and I'm interested in the distances and relationships to adjacent objects, foliage. Sometimes there is an object in this center, like a statue or fountain, sometimes just some rocks.
 
What's the best way to approach this?

[Kiesel]

You need some well known and measurable distances in your photos, artleast in some of them.
For that you can use
- coded markers (you can print them by PhotoScan Pro in Tools/Markers/Print Markers) or
- noncoded markers (see manual) or
- rulers or
- some simple known distances (better in atleast two directions and as long as possible to minimize the error).

Karsten

[Mr Whippy]

You can buy those small laser range finders to measure between a few different points across your reconstructed scene, and then correct the scene scale/orientation according to those measurements.

You could use anything to act as references.

I don't have the Pro version but do cloud corrections in Cloud Compare.

Setting the orientation to get the scene 'flat' is more difficult, but for your purposes doing it by eye is probably good enough.