Messages

31

General / Re: GCPs with no elevation value?

« on: May 06, 2019, 06:13:55 PM »

The workflow published by Agisoft has the user uncheck all photos and only check the GCP markers when performing camera optimization.  It seems to me, this may be recommended if cameras have no geolocation data in the EXIF?

What about this workflow?

Use "ADD Marker" function to identify visible GCP in one photo.

Edit Marker X and Y coordinates to correct, do not edit Z (altitude) as it will use altitude from EXIF in that photo which is a good estimate within 10m.

PLACE Marker (with corrected X Y coordinates) in at least two other photos

Optimize cameras (which have geolocation in EXIF) with photos and markers checked?  Or optimize with only markers checked?

There are SO many options (check boxes) on optimize cameras screen. Which ones to turn ON/OFF?

32

General / GCPs with no elevation value?

« on: May 03, 2019, 10:50:17 PM »

What if I have only X/Y values for my GCPs and no elevations values?  How do you incorporate those?  (I'm only needing to build a 2D orthomosaic map.)

Can I click "Add Marker" at the GCP in the photo and then just edit the X/Y values to correct the coords and thereby default to the elevation value in the photo?

33

General / Is this GCP Workflow correct?

« on: May 03, 2019, 07:40:22 PM »

Disregard... I figured it out.

34

General / Resizing Bounding Box Workflow

« on: April 22, 2019, 06:33:36 PM »

When you resize the bounding box, for the mesh model to adhere to the bounding do you always need to go back up in the workflow and start over back at generating the point cloud or can Metashape essentially "crop" the existing point cloud and mesh model to the new bounding box at the export step?  I assume it's the former and not the latter.

35

General / Export Model to Sketchfab with 200MB upload limit

« on: April 22, 2019, 06:23:44 PM »

Wondering what the best workflow if I want to generate a model for upload to Sketchfab and I want the best model quality that fits within the max 200MB file upload limit I have on my Sketchfab account.  Is it just trial and error to get something to come out near 200MB for the mesh and materials files?

36

General / Merging Everything

« on: March 21, 2019, 08:22:51 PM »

I created a model and forgot to include some of the photos.  All photos were take with the same drone/camera at the same time. I built the point cloud, dem, and orthomosaic. I want to avoid reprocessing everything.  I've added the additional photos as a second chunk and am aligning them.  Should I merge the aligned chunks and then reprocess the point cloud, dem and ortho, or can I just process the point cloud for the second chunk then merge everything into one and generate the new dem and ortho or can I even just process the dem and otho for chunk 2 and then merge everything together?

37

General / GoPro FishEye

« on: February 16, 2019, 05:11:09 AM »

In Tools -> Camera Calibration I can see Photoscan correctly identified the camera as a GoPro Hero 4 Silver.  However it looks to me on that on the photos used on the outer edges of my orthomosaic still have a warmed fisheye look.  The interior of the mosaic has no distortion due to the overlap.  Does the camera calibration not remove the fisheye from the photos?  Would I therefore get better results if I lens corrected the GoPro photos before bringing them into Photoscan?

38

General / Improving building 3D model

« on: November 08, 2018, 04:49:51 AM »

I'm trying to build a 3D model of the rooftop of a building which has structures on the roof like A/C unit (bit like 6ft x 6ft x 6ft unit) and smaller vents that are like 1ft square and 6 inches tall.  I took the photos with a drone where the nadir (overhead photos) were like 70% sidelap 80% frontlap.  I then did the same with 45-degree obliques in a criss cross instead back and forth pattern and finally oblique perimeter shots around the edge of the roof facing in also at about a 45-degree angle. 

Photographically the model is "so so"  some edges are pretty warped but that's pretty typical.  But when I export a mesh model, things like the big AC unit instead of being fairly rectangular it looks more like a blob even more so on the smaller object.  I don't expect t to get straight edges as I think that's pretty much impossible using photogrammetry (need to use Lidar for that)  But I'm wondering if there are suggestions (other than take more photos) to improve the model creation in Photoscan. 

I basically used all the defaults, like High Accuracy camera alignment and medium density point cloud.  It's about 350 20megapixel photos (not a very large roof as far as commercial standards, maybe 10,000 sq ft at most)

Hoping I can reprocess with some setting tweaks to make the model look a little better.  Basically I need to bring it into a CAD program to identify and make *approximate* measurements of the roof area and the significant object on the roof.  It just looks pretty blobby.  Or is the real solution to take a lot more photos?  I flew really close to the roof on this one only like 25 feet above it.  Maybe the fact I don't have any farther back photos showing larger areas of the roof could be contributing to the lack of straight geometry in the model?

39

General / Online Viewing of Images with Layer Toggle

« on: October 25, 2018, 08:32:06 PM »

Does anyone know of a service that I could share my orthomosaic export for viewing online and also add layers of jpeg overlay files that also allows you to toggle the layers on and off.

The only thing I've found that is close is the Online Photoshop Photo Editor knock-offs, but they easily crash the browser when bringing in gigapixel size images.

40

General / Re: Cleaning Up Mesh Model In CAD

« on: October 17, 2018, 03:54:22 AM »

I believe the only solution using photogrammetry is to export a GeoTiff, bring it into GIS software like QGis (or directly into CAD - any info on that out there?), then create a new layer to draft the shapes in 2D using the GeoTiff photo as your guide.  Then bring the model into CAD and the 2D outlines as another layer and at the verticle dimensions.  Everything is a box shape.  So even though the mesh model shows the rectangular boxes on the roof as round mounds you can use the top of the mount as the vertical dimension to extend the 2D outline of the footprint of the box into 3D space with the proper height.  Then basically just throw away the photogrammetry 3D model.

The photogrammetry models seems to be good for texture models, but as far as making precise measurements of objects in 3D space, it doesn't look to have a very good level of precision.  Whereas relative distance measurements between two points, especially in the horizontal plan on a GeoTiff, seem to be pretty darn accurate.  It's just the edges of objects with straight edges just aren't smooth.  I may experiment with Cyclone.

But in my opinion, the only way to really can a precise 3D mesh model of any object is using Lidar.

41

General / How Are Points Determined To Include or Include?

« on: October 16, 2018, 09:05:34 PM »

When changing from a higher to lower density setting for a point cloud, how does Photoscan determine which points to leave out?  Does it assign weight to points based on the amount of contrast around the point in the photo and therefore the points associated with the most discernable features in the photo remain where the more faint object have less points, or does it just uniformly remove points at specific distances?

42

General / Is There a Function / Hot Key to Change Model Perspective?

« on: October 16, 2018, 08:45:11 PM »

Is there a way, without dragging the mouse to just reset the model perspective to straight top down and to straight side view or do you just have to try to eyeball it using the mouse?

43

General / Re: Exporting 3D Model for Architectural Use and For Object Measurements

« on: October 16, 2018, 06:33:32 PM »

Well I gave Sketchup Pro a try and it handled a 90.000 face mesh exported from Photoscan quite well.

Anyone recommend any other programs to try.  Seems most of the free ones are 2D, not 3D as you point out.  Need one for Civil Engineering Projects too like AutoCad Civil 3D, but cheaper.

44

General / Cleaning Up Mesh Model In CAD

« on: October 16, 2018, 06:31:03 PM »

I've got a model of a warehouse roof.  There's objects on the roof like vents and such.  I need to use the model to design my solar panel array for the roof.  The mesh model that is exported from Photoscan is quite "busy"  is really only the best solution in this application is to load it into a CAD program and create a separate layer and essentially draft the outlines of all the objects I consider relevant (the edge of the roof and the 3D outlines of the objects on the roof?  It seems otherwise trying to decimate the point cloud and simplify the model does me no good as the photogrammetry output doesn't produce perfectly straight lines between the corners of the objects.

45

General / Exporting 3D Model for Architectural Use and For Object Measurements

« on: October 09, 2018, 04:55:27 AM »

I've got two applications I want to try.  Both involve bringing the 3D Model (generated from drone images) into CAD design software such as AutoCAD Civil 3D (or AutoCAD Architecture)

The first application is so I can take measurements of the various aspects of the structure (roof area, height of building, height of ventilation stacks)

The second application is to use a model of structures and surrounding terrain to superimpose the design of a new building within.

Assuming I'm using AutoCAD Civil 3D, what would be the optimal export formats in Photoscan for these two applications?