Messages

496

General / Re: Keeping world coordinates a in zbrush

« on: October 02, 2013, 10:05:10 PM »

Yes, it is in Pscan Pro. Export model... then choose a filename and folder and a dialog then opens with the options for coordinate system and shift vector.
 

497

General / Re: Keeping world coordinates a in zbrush

« on: October 02, 2013, 01:05:55 AM »

Hi Gawin
In the export dialog you should choose the coordinate system of your project and write a traslation vector that brings your model to "near" (0,0,0). I usually take the integer part of the first GCP coordinates (with the same sign), take a screenshot of the dialog and save as "traslation.jpg" in the same folder as translated obj just in case.

Then go to zbrush and cook the mesh.

When you ar ready to reimport, use the very same coordinate system and vector including the same sign. If Zbrush does not change scale or anything else, I guess you will have the model back in its right world coordinates. Please tell us if works

Good luck

498

Feature Requests / Re: querying and extracting coordinates from a model

« on: September 18, 2013, 10:40:37 AM »

Hi simcklethwaite
That has always been posible. Just put markers in the model on desired locations once it has been georeferenced and see their estimated coordinates by clicking "view estimated" (second button from right in GC pane toolbar). You can also export their coordinates if you check "save estimated values".
Regards

499

Feature Requests / scale bars

« on: September 17, 2013, 11:25:27 AM »

1. Exportable to text file just like the rest of ground control actors.
2. Default name should be that of the two markers a scale bar links, for instance "point 1-point 2". A comprehensive link between a scale and the markers it has as end points, should survive to any renaming and/or must be explicit as a property of the scale bar
3. I'd rather prefer the old fashioned tool for picking scales on model window better than choosing two GCP and right click for calling contextual menu.
4. Scale bars could be exportable as segments in some cad formats. That would allow a primitive form of restitution.
Regards! and congrats for my favourite dev.team

500

Feature Requests / Re: Scale in Otrhophoto exporting

« on: September 17, 2013, 11:03:00 AM »

I'd suggest to have full printing capabilities built-in.
I'd love to have on board dialog for direct output to pdf, to system printer or to image file
It could boast a handfull of useful settings such as:
Resolution, scale, position on sheet, rotation, coordinate grid superimposition, scale bar, GCP on/off, etc.
Also print as point cloud with some options for handling point rendering and size would be just great. Dense point cloud printing for small scales sometimes yields to nice true orthos much better than those out from mesh-based orthorectification.

501

General / Re: twin cameras processing for aerial photogrametry

« on: July 01, 2013, 05:11:52 AM »

I guess the aerospace's question is not being well understood. If I'm right, the advantage he would want to exploit comes from the wider field of view as a result of the sum of that of a pair of divergent cameras that might overlap even by just a small but constant percent.
I would not expect this setup to work well in general because  Photoscan would try to orient each photo in the pair as an independent camera, not only in terms of intrinsic parameters but also exterior ones. The closeness of the two photo-centers in a pair would lead to weak resections with bad results.
The plan could work if you managed to split the projects in chunks that had no pairs inside. If the successive strips are flown in opposite directions then you could form chunks with every two successive pass halves.
>LLLLLLLLLLLLLLLLLLLL
>RRRRRRRRRRRRRRRR.     TURN
==============}chuk one with R photos
RRRRRRRRRRRRRRRR<
LLLLLLLLLLLLLLLLLLLL<
==============}chunk two with L photos
>LLLLLLLLLLLLLLLLLLLL
>RRRRRRRRRRRRRRRR.     TURN
...etc. This planning would require ground control for every two rows... And that sounds bad.
just thinking, a better solution could be to alternate trigger of left an right cameras so they did not fire simultaneously, this would work well if you let left an right camera overlap over 30% a variant that could also be possible with one single camera capable of tilt from left to right in cycles... Mmmm sounds feasible, but still much more complicated than shortening the focal length of your camera.
By the way, what cameras are you flying with?
Regards

502

General / Re: Simple workflow question - build geometry?

« on: April 09, 2013, 05:20:24 PM »

this is not correct. The actual bundle adjustment (which computes camera calibration and orientation parameters and creates the sparse point cloud) happens during camera alignment. The sparse point cloud contains true 3D points. Nothing 2D here.

Let me respectfully insist in that it is correct from my point of view.
Feature points are detected in every single image (2D) before orientation, and are paired by comparison of clusters of pixels (2D to 2D).
lots of statistically-approved couples (x,y) & (x',y') enter in equations that yield solutions to unknowns:  lens parameters and also center and attitude of cameras and at the same time x,y,z for the feature points are calculated (so, no role is played by the third dimension until now). So the result is 3D but features are two dimensional as they are just singularities in the appearance of a certain groups of pixels not necessarily linked to actual shape-features but to photo-features.

503

General / Re: Simple workflow question - build geometry?

« on: April 09, 2013, 02:33:01 AM »

Does "build geometry" improve the accuracy of the original point cloud points or does it just add more points/facets?
Thanks.

Yes. As far as the sparse cloud is built on matched "feature points", it does not have nothing to do with the actual terrain topography but just with some points identified as features because of their appearance in the photos (vicinity contrast or whatever that made them distinctly identifiable for some detection algorithm). You should understand this is just a 2D step
This nature makes them well-suited to provide optimal correlation values and thus are great for inner and outer camera orientation parameters estimation.
If you build geometry you should get a better terrain description even after a strong decimation (now the third dimension matters) to a number of points below the population of the initial sparse cloud.

I wouldn't expect to infer good breaklines from the sparse point cloud but on the contrary you would see them neatly rendered after dense model decimation.

Regards!

504

General / Re: UAV photos look reversed after align (canon 1400sd)

« on: February 19, 2013, 04:34:08 AM »

1 yes it is normal... or let's better say it is the way it happens. I find it weird too
2 Not normal at all. Help Pscan with three or more pass-points (shared markers between chunks).

505

General / Re: 5 or 6 tries, no results! Basic questions here

« on: February 19, 2013, 04:27:39 AM »

I would suggest one more:
If your subject did not fill the image frame and most part of photo is out of interest you could add good extra-actors (simple stones may help) around your object. Filling the photo frame as much as possible you will get better results and you can mask unneeded parts after alignment is done.

506

General / Re: Modeling a bomb/mines field

« on: February 08, 2013, 03:53:53 AM »

Differential GPS is not possible on cheap UAV 

If by cheap you mean trimble X-100 I'd say you are wrong in two senses. 1. xwing is far from cheap, imho. and 2. dgps for sub-dm accuracy is actually possible on board of small uas... just wait a couple of months. It's gonna take longer for kinematic, but is very on the way for post-processed solution.

On the other side, have you considered manned solutions like parafan or ul (ultralight aircraft)? this could fit perfectly and you could carry with you surveying-grade gps stuff.

507

Feature Requests / bounding box

« on: February 06, 2013, 04:20:42 AM »

• bounding box bottom is too subtle
• once the model is georeferenced, bottom should be aligned to xy plane automatically
• once the model is georeferenced, box rotations about x & y should be locked unless user wanted them free. A contextual menu with lock-toggles for each axis could do while allow panning is not a must here
• render the bottom face differently when is facing up
• ... last but not least. Dear Agisoft team, please, be my heroes!:  Could you please consider using different cursor styles suited to each tool/context?

Best regards
Jos? Mart?nez (Geobit)

508

Feature Requests / Re: Cut and trim by masks

« on: November 25, 2012, 09:51:49 PM »

I tend to agree this could be a very good idea but with exceptions (so mine is +0.99). I've noticed that oversizing masks helps to get better geometry. I mean that if you mask object zones nearby the very silhouette or intentionally mask image regions corresponding to object's faces that are very oblique to point of view, this improves geometry and help to get cleaner model. In this case if you trim the model by-mask, you'll actually destroy some good geometry parts ...
So, a good idea that needs to be fine tuned and carefully engineered

509

Feature Requests / Re: "base height field"

« on: November 25, 2012, 04:33:54 AM »

I guess that you might be wrong. height-field does not model the top envelope, if it was that simple you could just rotate your cloud 180 about x or y and model it as height-field and then rotate again and invert face normals... but my bet is that you would have the very same surface.
Height-field is agisoft's name for one implementation of some of the classic 2,5D triangulation algorithms,  probably Delaunay.

I'm not saying that your proposal is a bad idea, but just wanted to suggest a workaround.

510

Feature Requests / lasso selection

« on: November 24, 2012, 05:10:37 AM »

I voted for an irregular form selection tool, so THANKS.
But I just can't manage to do fine with the lasso tool unless you have a very steady hand or a digitizing board instead of a mouse. So I'd be thankful if polygonal selection by entering vertices of a fence was also possible as it works for image-masking