Alignment of region

[RalfH]

After photo alignment, PhotoScan creates a region around the object. This region also determines the plane of projection when creating an orthophoto texture. At the moment (version 0.9), there are only two ways of manipulating this region: resize and rotate. I think it would be very helpful if the possibilities for aligning this region could be improved, for example by using a small number of tie points (e.g., place 3 points onto the model surface to specify the plane of orthophoto projection).

[Background: I am using PhotoScan to create 3D models of pits excavated into a sloping surface; they commonly have three sides at approximately right angles. I now want to create separate othophoto textures for the three sides to use them as a basis for stratigraphic sketches.]

I think this would also be appreciated by people modelling buildings and other objects.

[Alexey Pasumansky]

Hello RalfH,

Actually it is possible to export orthophoto in any projection defined by three markers (or two vectors).
In the export orthophoto dialog you need to select Planar projection type, Markers projection plane (assuming that you have already placed markers defining the projection plane) and then select corresponding markers that defines the orientation of X or Y axis.

[RalfH]

Hello Alexey,

unfortunately, I only have the standard version (not PRO), so for me the only way to align the orthophoto projection plane seems to be through modifying the region. Or is there another way?

[Alexey Pasumansky]

Hello RalfH,

In Standard edition (if you are generating texture in orthophoto mode) the only option is to rotate region so that red-colored side is parallel to the projection plane.

[RalfH]

Hello Alexey,

this is regrettable, especially as PhotoScan applies the changes in region orientation to orthophoto texture only after the model is built again (which is time-consuming).

[Alexey Pasumansky]

Hello RalfH,

I think, if you cut all the faces except the area of interest (each one of three sides) and create the texture in orthophoto mode. Let me know if it helps.

[Alexey Pasumansky]

And another timesaver option is to reconstruct the geometry in the smaller bounding box (with area of interest inside) without rebuilding depth maps.

[RalfH]

Hello Alexey,

thanks. I will try to see how this works.

Also, as I am partially colourblind, it's very tricky to see the pale red of the projection plane. Is there a way to change the colour settings of PhotoScan?

[xabierr]

Hi Alexey,

Is there any way of aligning the region when exporting points the same way you can when exporting the orthophoto (i.e. using 3 markers)? How can we "shift" the pointcloud to align to markers?

cheers,

Javier

[Alexey Pasumansky]

Hello Javier,

Orientation of the bounding box doesn't affect the points cloud (sparse and dense) as long as it includes complete reconstruction area and all the points you wish to export.

Bounding box orientation does matter only in case of mesh generation in Height Field mode, when red-colored side of the box should be parallel to the XY plane.

But probably you are speaking of model orientation in space? Then you do it manually using Rotate Object tool, or create a custom Python script.

[xabierr]

What Im looking for is being able to export both the orthophoto and DEM (or cloud point) using only markers and no GCPs. thanks for the help