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Messages - Dave Martin

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General / Re: System requirements - where is my fault ?!?
« on: February 28, 2019, 07:20:48 PM »
You need to give more information - what version of PhotoScan/MetaShape on both machines, and copy of the console log up to and including where it crashes.

General / Re: Using a GoPro & Photoscan
« on: February 22, 2019, 11:43:13 AM »
Just a tip: You might find a lens profile for the gopro for lightroom. You can then back process the images there and give photoscan the corrected images.

This is absolutely what is not recommended. If you really have to, you can use an external tool to adjust the WB or other tonal/exposure levels. BUT adjusting the geometry before using PhotoScan/MetaShape (or any other SfM software) will give inferior results.


How have you input height values into your project - do you have Ground Control Points (GCPs)? or are you relying on camera positions?

If it is just camera positions, I'm going to hazard a guess that your UAS might be a DJI? - there is a well-known issue with DJI whereby they load altitude above take-off point - have a search on the forum for    DJI height   for more info and means of fixing this deficiency.


General / Re: cannot import imags position reference data into project
« on: February 13, 2019, 10:30:43 AM »

Can you show a screenshot of the CSV and a screenshot of the folder with the images (with file extensions visible) ?


General / Re: Low Resource Usage in new setup
« on: February 12, 2019, 10:27:58 AM »

The subject of how Windows reports GPU usage has been covered on this board a number of times, I've just done a quick search for "GPU usage" and this is one of the posts that describes how to monitor GPU when used as a computation engine:


General / Re: include feature that is submerged in water periodically
« on: February 09, 2019, 01:06:01 PM »

If there enough images with the tree in, then yes, I would try and mask-out the area where the tree is 'should' be in images where it is covered.

As an aside, it sounds as if you're working on the surf line - beware that alignment can be challenging as waves roll in & out between photographs.


General / Re: Obtaining geographic coordinates (x,y,z) of markers
« on: February 09, 2019, 01:02:31 PM »

As I understand your description, you only have one point with known (arbitrary) coordinates. If you were to export your model, that would be the only point for which x,y,z is known. Using scale bars, you have defined the scale but not the orientation of the model.  If you want to export point triplets, the model needs scale and orientation. To orient the model accuratley, you would normally need absolute minimum of three points.

Also, you say you are not using GCP at all - you will need some points as check-points; and, depending on your UAS and if/how you are acquiring camera positions, you may need GCPs to make an accurate model.


General / Re: Flood Simulation experience?
« on: February 02, 2019, 04:53:15 PM »

I haven't anything I can share right now, and am not in front of my GIS workstations so can't even screenshot right now, but some quick points:

There's no need for LAZ - LAS will do fine (LAZ is just an *open* compression mechanism for LAS).

I don't use a combined LAS/LAZ and ortho, or indeed a colourised point cloud. The LAS, and ortho if used, are completely separate ingredients.

Depending on the context, I sometimes do water level work with just a coloured elevation scale like in that video you linked to, other times I will overlay an orthophoto on a DSM to show more detailed impact.

In GlobalMapper I just import either (i) LAS DTM or (ii) LAS DSM + ortho. If using ortho, I then overlay the ortho - so long as both are geo-referenced that's all that's needed, and the DSM and ortho can have different sources.

In GlobalMapper I then activate 3D, click on the [enable water level] button and use the [water level up] / [water level down] buttons to adjust the water level; as you click up/down a box on the screen tells you how high the water is at present. I usually use 0.5m increments; you can set the increment and the starting water height.


General / Re: Flood Simulation experience?
« on: February 02, 2019, 01:28:42 PM »

I don't know how it would inter-work with STL output from PhotoScan/MetaShape, but I do quite a bit of this type of modelling using LAS/LAZ and orthophotos - so it might be worth trying alternative formats if you can (I use GlobalMapper and loading takes sometimes a couple of minutes for a couple of square km and then changing virtual sea-level in synchronised 2D and 3D just takes a second or two every time you click for an incremental rise.

If you're after doing watersheds, then my preferred tool for that is Surfer from Golden Software.


General / Re: Import Mesh
« on: January 30, 2019, 12:07:51 PM »
One possibility is that the bounding box no longer encompasses the imported points. If so, you might find this thread helpful:


General / Re: DEM generation takes too long (build dem)
« on: January 30, 2019, 09:43:55 AM »

Re forward overlap, you say >80% - that might be the reason. It has been known for some time that 'excessive' overlap can cause issues as (if I remember correctly) it can cause a near-exponential increase in the number of potential tie-points/matches. I haven't had this problem (my rigs allow me to trigger the camera every X metres) but from what I've seen here on the forum (i) the new version may be more sensitive to this due to improved algorithms, but (ii) there is now a feature to thin-out excessively dense overlaps.


General / Re: Move/displace all sparse cloud points on Z-axis
« on: January 30, 2019, 09:36:14 AM »

When you export a model, you can apply a shift in X and/or Y and/or Z (page 39 of current manual).

Is the model georeferenced using GCPs? otherwise, how are elevations being input into PhotoScan/MetaShape?

(if you have different heights from different heights, I could guess you might being using DJI kit? - in which case search here on the forum for DJI height issues and you'll find plenty of threads. Also, if you're using the sea's edge, is it just tidal variation you're seeing? - tidal range at equinoctial springs in my location can be of the order of eight metres between high and low water).


General / Re: DEM generation takes too long (build dem)
« on: January 29, 2019, 09:55:04 PM »
.......Any idea why this lack of performance might be happening on this corridor mapping project?

JMGC, firstly, just as an aside, one pass with no side-lap is not ideal.

You said earlier that you "Usually use 80% forward and 65% sideways overlap."
With respect to the 'problem' corridor project, can you advise the overlap between consecutive images on this one path please?

Also, you said other corridor projects were at a more acceptable performance - were they processed in exactly the same version of PhotoScan/MetaShape?


General / Re: DEM generation takes too long
« on: January 29, 2019, 02:03:56 PM »

Can you advise how much overlap (forwards and sideways) you have for both the square and corridor projects? and how many parallel runs were used for the corridor project?

General / Re: Camera Export in BINGO is locked to local coordinates
« on: January 19, 2019, 02:45:39 PM »

I've not had occasion to try export in BINGO format, but I do know that if a project isn't properly geo-referenced throughout, then certain exports are limited to local / un-calibrated units.


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