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Topics - cbnewham

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Bug Reports / Processed thumbnails load too slowly
« on: April 22, 2021, 10:37:13 AM »
Thumbnails load incredibly slowly once the depth maps have been generated.

What's worse is that only a small number are loaded - if you scroll down, it forces more to load and the earlier ones disappear. It doesn't behave like this when the photos are initially loaded - everything is loaded super fast and always visible. It's been like this on every version up to the one I'm using (1.7.0) and I've always assumed it was a bug.

If this is not a bug, please provide a way to switch this behaviour off (so that only the thumbnail is loaded, and not any other background information). With many hundreds or thousands of photos it makes the thumbnails unusable.

General / Thumbnails take ages to load once processed
« on: April 19, 2021, 06:30:44 PM »
Has anyone else noticed how incredibly slowly the thumbnails load once the depth maps have been generated?

What's worse is that only a small number are loaded - if you scroll down, it forces more to load and the earlier ones disappear. It doesn't behave like this when the photos are initially loaded - everything is loaded super fast and always visible. It's been like this on every version up to the one I'm using (1.7.0) and I've always assumed it was a bug.

Is there any way to switch off this behaviour?

BTW, I have 64Gb of main memory in my machine, so I don't think that's the problem - task manager shows only 15Gb in use by everything.

General / Refine mesh - no updates
« on: October 21, 2020, 02:34:26 PM »
I've been trying the "Refine Mesh" feature for the first time. It's been going for several hours, not using very much CPU, GPU or main memory (although GPU memory is being used). The console just says "Refining model...".

The total completion bar looks to be at about 5% but remains unchanged since the process did the initial setting up. There is no estimate given for the length of time the process may take - that's just blank.

Does the console ever update at all? There seems to be no debug output for this feature, other than at the very start.

I'm debating whether to stop the process or just let it run - but it could be in an infinite loop for all I know. :-(

Question: Is the process mainly tied to the number of photos, or to the number of faces the mesh has?

Using the latest version of Metashape. 2019 Razer laptop with 64Gb memory and top-end Nvidia graphics card.

My project has 2800 cameras and has successfully created the model. However, I am unable to get it textured. It always stalls at 70% and can be left for days and does nothing further.

I notice that every time it shows it is "falling back to legacy parametrization". What does that mean? The "legacy" version doesn't seem to output any information to the console after stating how many charts it is packing.

I've tried:

- Decimating the mesh (nominally 17m faces) down to 1 million.
- Reducing the texture size from 20,000 (the maximum I can generate with my graphics card) to 5000.
- Disabling all the cameras and then enabling 5.

Apart from the number of "charts" it packs, these changes make no difference and it always stops at 70% and does nothing after very long periods of time.

General / Reduce overlap feature
« on: July 30, 2020, 02:16:09 PM »

I think the new feature for disabling images with a lot of overlap is a nice idea. Unfortunately, I have not found this of use. Even if I set the overlap allowance to "high", the resulting model is very noisy compared to using every image (image sets of the order of 800 to 1000 images).

I don't know the details of how the overlap is being determined (presumably by looking at the surface of the rough model that is needed in order to determine overlap, to see how much is shared between images).

It would be nice if there was an alternative method, which I think would work along the lines of removing cameras that have a close spatial distance and view orientation (perhaps ignoring rotation). For my cases, I think that would remove quite a few similar pictures without impacting the resulting model.

General / No points found for photo with detail
« on: December 26, 2019, 10:38:53 PM »
My projects are usually 400 to 1200 images in size. I have noticed for a few of them that no points are found for a few photos where there is plenty of detail. I've tried masking any background or blurry foreground out and I've also tried varying the total number of key points at the start but it makes no difference - the same photos always come back with no points - that is, zero points, not just points that weren't matched - during the initial processing phase and hence can't be matched.

I attach an example (the attachment is 25% of the original photo size). Other similar photos from the same area of this sculpture with similar photographic viewpoint produce hundreds of points.

Why would this be?


Is there any way to stop the viewport camera from being reset when doing a realignment?

I align the cameras, get the tie points of the sparse cloud and then find I have mis-aligned cameras. I filter on those cameras and then reset their alignments (sometimes I do this one at a time so as not to replicate the incorrect alignments). Unfortunately every time I then select a camera or cameras and align them the view jumps back to a pre-determined view. This is really annoying! I can't see if the points being added to the sparse cloud are being added back in the correct locations because the section they are part of may be off screen in the view.

This also happens sometimes when saving the file - equally annoying.

Is this possible Alexey?  I don't see why not as the bounding box isn't changing from the original alignment of all the cameras.

General / New article on photogrammetry / Metashape
« on: December 06, 2019, 03:49:02 AM »

Not really sure if this should go in the General forum, but I've had an article published on using photogrammetry to record church architecture and art. The photogrammetry was carried out using Metashape.

I have placed a copy of the article here (originally published last month in "Ecclesiology Today"):

Feature Requests / Iteration for camera alignment
« on: October 14, 2019, 02:00:09 PM »
I find that when I align a large set of cameras using the Generic setting that I end up with photos that have not been aligned. If I then select these I can usually align them. Sometimes I still end up with some unaligned cameras - so repeating the process by selecting those and aligning them usually works.

It would be nice if Metashape had an option to specify the number of iterations of alignment in order to perform this task automatically. So - alignment over the entire set of cameras as we currently have, then iterate a user-set number of times on anything that has not been aligned.

Feature Requests / Clear markers for "not aligned"
« on: October 14, 2019, 01:55:27 PM »
I find the current grey ticks make it very hard to see what has and what hasn't been aligned.

It would be nice to see much better visual indications of what photos have failed alignment. It would be even better if whatever coloured markers are used could have their colour changed in the Preferences.

General / Best practice for chunks
« on: October 10, 2019, 06:56:39 PM »
Does anyone have a document or website detailing the best practice with chunks? The manual just tells you how to create them and copy cameras to them.

In my case I have a model which I can't generate in one go because the mesh creation from depth maps runs out of memory.

In the past I've loaded all the photos in, created the sparse cloud, and then duplicated the chunk several times and in each one selected from the 3D view a subset of cameras to keep active and disabled the others (keeping some overlap of selected cameras between chunks), then created the dense cloud, then merged the chunks, exported and decimated the dense cloud, then imported and created the mesh.

I'm not sure if this is the way to do it or if there is a better way. I'm also unsure if this will work using the new mesh from depth-map generation.

Thoughts (or tell me this is not the best way!)


General / Find cameras from points in sparse cloud
« on: October 07, 2019, 04:49:25 PM »
I have had a look through the manual but cannot find how to find a way to see which cameras produced which points in the sparse cloud.

I've not really encountered problems up until now but today I generated a sparse cloud that clearly has a group of points forming a surface intersecting the rest of the correctly generated cloud - so they must have been produced by a group of cameras with bad alignment.

Is there a way I can select some of the errant points and then show the cameras/photos involved?

General / Metashape - an unfortunate choice of name
« on: March 26, 2019, 10:54:55 AM »
The product is great and has improved in leaps and bounds over the years I've been using it. Keep up the good work.

However, why oh why did you choose the name "Metashape". While "Photoscan" wasn't exactly a fantastic name, at least it was memorable and also indicated what it did in the name (scanned photos, sort of). "Metashape" is just meaningless; "self-awareness of shape"??? That's got very little to do with photogrammetry. A dull, grey name that one struggles to remember.

Also unfortunate timing - last year I wrote a journal article about using photogrammetry for recording architecture and church monuments which is due to be published about now. Of course, it is called "Photoscan" in the article.

Bug Reports / No longer able to view Dense Cloud in latest version
« on: January 02, 2018, 01:42:19 PM »
Version 1.4.0 build 5650.

Maybe I'm doing something wrong, but I've just upgraded to the latest version of PS and I can no longer view the dense cloud. The menu option: Model -> View Mode -> Dense Cloud gives me another sub-menu with "Filter by selection" and "Reset filter", both of which are greyed out and neither are what I want.

Build 5076 allows viewing the dense cloud under that menu item, so either it's moved and I can't find it or it has been left out by mistake in 5650.

General / Problems with dense cloud using two different cameras
« on: April 07, 2016, 12:47:36 PM »
While I have created models successfully with two cameras before, I've run into real problems with a recent situation in photographing a piece of sculpture.

I have two cameras: Canon 1dsIII and a Panasonic GM1. Both have made a couple of hundred images each for the same scene. I began the imaging with the Canon and swapped to the GM1 half way through (battery running out of power). There is plenty of overlap between images themselves and between the image sets from each camera.

The sparse cloud is generated successfully and the camera positions all look to be correct for both cameras.

However, when I generate the dense cloud, the images from the GM1 seem to be missing for great swathes of the sculpture - the point cloud has large gaps in it with sharp edges, yet these areas are covered very well by the images, and the gaps also have points in them in the sparse cloud.

If I create the sparse and then the dense cloud by using just one or the other camera's images then the result is fine (although, obviously, incomplete because not all areas were imaged with one camera).

Looking at the camera params after the initial sparse cloud is created, I notice that photoscan has not updated the camera distortion parameters for the GM1. They are updated if I exclude the Canon images.

Any ideas?

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