Messages

406

General / Re: 3d digitizer software

« on: July 07, 2015, 11:27:31 AM »

Virtual Surveyor by Geoid.be sounds pretty like what you want. Anyway digital stereoplotters remain as the best choice for clean vectorial feature collection, while DEM/DSM + orthoimage monoploting-based methods are prone to big errors in elevation.
I you need further information please send pm

407

General / Re: Processing bands seperately

« on: May 25, 2015, 11:36:09 AM »

Yes: Just add a good collection of markers on ground features shared (having identical names) by the three datasets, after alignment of photos try align chunks by markers. You should have then the three chunks in the same coordinate system and can follow the suggested procedure. Do not expect perfect results.

408

General / Re: Processing bands seperately

« on: May 22, 2015, 01:28:38 PM »

1 align the three datasets in three chunks and use the same GCP set to have them oriented in the very same coordinate framework.
2 process dense point cloud and height-field mesh for RGB chunk (as its likely to deliver the best results)
3 export the mesh and import the same into the remaining chunks (you dont need to create dense clouds for them, which is great)
4 export ortho for each chunk
I recommend to set identical bounding box numerically by means of py commands so your orthos share also size

Regards
GEOBIT

409

General / Re: Scanning my girlfriend

« on: May 11, 2015, 11:16:07 AM »

yes it somtetimes happen tha pscan fails to align some photos without evident reason. Try to select in small groups photos 5-10 that are connected to those that have aligned well, righ-click and select align photos in the context menu. Also try setting tiepoint limit to zero or to a number much higher than default value.
let us know if you are lucky and do not give up with this girlfriend... this is not that important! ;-)

410

General / Re: Z axis reversed

« on: April 28, 2015, 09:29:05 AM »

This is a very badly distributed set of ground control points. besides, might it be you have swaped x and y? check if your gcp coordinates are Easting-Northing (X first) or the opposite Northing-Easting (Y first)
I respectfully would recommend you to let a surveyor/photogrammetrist to do this jobs. Do not fly over people or vehicles unless it becomes absolutely necessary, civil drones can kill too!
Regards
GEOBIT

411

General / Re: Height field 'direction' in mesh creation not parallel to z-axis

« on: April 19, 2015, 02:39:35 PM »

I've answered here http://www.agisoft.com/forum/index.php?topic=2921.0

Cheers!

412

General / Re: Arbitrary or Height-field

« on: April 19, 2015, 02:36:23 PM »

The z-axis considered for the 3.5D projection is that of the bounding box, and it might not be coherent with your coordinate system.
Unfortunately there is no button to make bounding box to have z axis parallel to Z of the ground control. As far as I know, the only way to force it is to run a python scritp. (http://www.agisoft.com/forum/index.php?topic=2552.0)

You can chek if your box is well oriented by hiting num 5 key to set non perspective view and then num 3 to watch your model from one side with z up... if you see the box is rotated then you know why your heightfield is wrong.

Regards!
GEOBIT

413

General / Re: Masking out background detail

« on: April 12, 2015, 10:48:29 PM »

You may try this:
Calculate photos orientations
Reduce and orient the bounding box so it encloses your trunk in the sparse cloud, then build dense cloud with lowest or low quality and mesh that cloud as arbitrary.
After that you can mask all photos by using this rough first approach. (mask import from model)
Then re-run dense cloud at higher specs

414

General / Re: lens to Sony nex 5 and Lumix GM1 and GM5

« on: March 16, 2015, 10:39:05 PM »

For the Micro four thirds I'd recommend:
1. Oly12mm
2. Oly17mm (the expensive one)
2. Panaleica 20
3. Oly25mm

Take care with focus in the NIR camera, some lenses can't focus. it can vary from one camera model to another.
but more important. be aware of rolling shutter with GM's, you will have insane error if you use electronic shutter so you MUST use speeds under below 1/500
BTW why did you choose two diferent cameras?
To help you to understand calculation of the best focal lenght you should consider:
a) you should not fly over 120m because international air regulations say small civil UAVS are not allowed to fly higher than 400ft
b) having the flight height limited to 120m, you need to know the width of your sensor in mm and in pixels to obtain the actual pixel size (usually something about 5 microns). Finally you can say
Height_over_ground[m] * pix_size[mm]=GSD[m] * focal_lenght[mm]

415

General / Re: Tie points once again

« on: March 09, 2015, 03:05:09 PM »

I personally find that the default 10.000 limit causes bad alignment in too much cases. I wonder how the quality assessment is done.
If reprojection error is the only factor... What if the initial guess of camera orientations (internal and external) is not good enough?
In my experience, the Initial guess (before optimizing) almost always needs refinement. If that is the case for most consumer (non metric) cameras, it is likely to happen that tie-points filtering before optimization may lead to kill a lot of them for no good reason, specially near the frame borders where complex distortions are bigger. This seems to me to lead to alignment failures.
Can Alexey give us a good clue to understand the need for thinning the sparse cloud? thanks in advance.

416

General / Re: labeling some parts of the 3D reconstruction

« on: January 28, 2015, 10:35:13 PM »

You can do it outside Photoscan: here you are two examples:
http://youtu.be/Rb3j1H4vfjM
http://youtu.be/1mFVoSQnivA

Kind regards

417

General / Re: Alignement problems

« on: December 16, 2014, 03:27:21 AM »

Max dimension will be the only setting available when no ground control is provided. You'll see an "R" standing for reference when the chunk have external orientation or scale (set by beans of one or more known distances).
If R is shown following chunk name you'll be allowed to export ortho at a given pixel size.

Kind regards,

José (GEOBIT)

418

General / Re: Alignement problems

« on: December 15, 2014, 12:41:50 PM »

I never said to split the project.
just select bunches of overlapping photos within the failing chunk after their alignment has been reset and right click for align them step by step

GEOBIT

419

General / Re: Alignement problems

« on: December 15, 2014, 02:02:37 AM »

Select all photos and reset alignment, then select the firts 10 (is just a number to try) and right clic to align selected.
If that goes, keep selecting them and aligning by groups...
I have needed this approach many times when no good reason for alignment failure is found.
It may also help if you export camera calibration from a sucessfull project that shares the same camera/lens and use the same parameters. It might be a matter of bad initial guess of inner orientation.
Tell us if it works
Regards

GEOBIT

420

Python and Java API / may not be a bug but simply a change

« on: November 03, 2014, 12:06:28 PM »

well I was happy using a python script Alexey published for leveling the bounding box but now it is not working any more with 1.1
Can you tell me what should I change in order to make it right?

Console: Traceback (most recent call last):
  File "C:/temp/reset_bound.py", line 4, in <module>
    chunk = doc.activeChunk
AttributeError: 'PhotoScan.Document' object has no attribute 'activeChunk'

******************************************************Python script********************
import PhotoScan, math

doc = PhotoScan.app.document
chunk = doc.activeChunk

if chunk.transform:
       T = chunk.transform
else:
       T = PhotoScan.Matrix().diag([1,1,1,1])

v = PhotoScan.Vector( [0,0,0,1] )
v_t = T * v
v_t.size = 3

if chunk.crs:
   m = chunk.crs.localframe(v_t)
else:
   m = PhotoScan.Matrix().diag([1,1,1,1])
m = m * T

s = math.sqrt(m[0,0]*m[0,0] + m[0,1]*m[0,1] + m[0,2]*m[0,2]) #scale factor
R = PhotoScan.Matrix( [[m[0,0],m[0,1],m[0,2]], [m[1,0],m[1,1],m[1,2]], [m[2,0],m[2,1],m[2,2]]])
R = R * (1. / s)

reg = chunk.region
reg.rot = R.t()
chunk.region = reg
**********************************************************end*****************************