Incomplete mesh in V1.71 where V1.65 was able to construct a closed mesh

[jnb]

PM mark is the new depth map generation method introduced in v 1.7, that's all I know !

[RHenriques]

I've tested jnb's sample fotos and the reconstruction is near perfect. You might have been using some wrong parameter. I've used everything in default and in highest quality in the latest 1.7.3 version. See attached image. Also check this small video of the reconstruction.

https://u.pcloud.link/publink/show?code=XZxiCWXZkVzTqnhjlx8MdH14gX8cXLssAlrV

[jnb]

Thank you for testing @RHenriques. Unfortunately, the error in the mesh is difficult to see on the sample as the data set is vastly incomplete and was only made to share image quality.
Alexey reprocessed the whole set on his side in high quality and the result in v1.7.3 is alas not good as you can see in attachements. He also processed the sample, and the v1.7.3 is also incorrect compared to the v1.6.

[RHenriques]

It's strange because, on my side, with default parameters and version 1.7.3, everything comes out as you can see in the above images, even done with your 11 image subset. Can you make an extraction of all the parameters used? My test was done with mesh reconstruction from depth maps with all parameters in default. Try to do things from the beginning in version 1.7.3 and maintain the 40 000/4 000 numbers, in the alignment step, for the Key point and Tie Point limit respectively. Also see if you are not using too much overlap in the complete set. Sometimes, too much photos can lead to a wrong reconstruction.
If you use only the 11 images from your test set the results are similar to mine?
Can it be related with hardware differences?

[jnb]

If someone wants to play with it, I updated the sample data set to be more comprehensive.
Just to be on the safe side, I also reprocessed it with PM mark and SGM mark, with all others settings to default. Medium quality, Mild filtering.
Here is the tweak given by Alexey to change the depth map process : BuildDepthMaps/pm_enable

edit : @RHenriques, just saw your post. If you have the time, I am curious to see your results with the more complete data sample. I also didn't try to process it myself in high quality, as it is too time consuming and not needed for my work. This is I think the only difference.

[wojtek]

It's strange because, on my side, with default parameters and version 1.7.3, everything comes out as you can see in the above images, even done with your 11 image subset. Can you make an extraction of all the parameters used? My test was done with mesh reconstruction from depth maps with all parameters in default. Try to do things from the beginning in version 1.7.3 and maintain the 40 000/4 000 numbers, in the alignment step, for the Key point and Tie Point limit respectively. Also see if you are not using too much overlap in the complete set. Sometimes, too much photos can lead to a wrong reconstruction.
If you use only the 11 images from your test set the results are similar to mine?
Can it be related with hardware differences?

Yes, either that or mask your photos by depth, so only sharp areas remain (see Generate Masks command).

[Mak11]

I think that its perfectly clear from the results shown in this thread; that the new depth maps generation method suffers from issues when the result are vastly different (better) when the depth maps are generated via the previous method with the exact same data set (using exactly the same settings)

Mak

[Paulo]

Hi Jnb,

I processed a model with 14 images downloaded from your shared drive. Comparing the 2 depth map generation versions (PM latest and  previous), I do not see a great difference between the 2. Both models generated from depth maps with medium quality and mild filtering. Note that PM version generates much more detail (double the number of faces). However in case of low performance GPU (GeForce GTX 670MX), depth map generation time is greaty increased for latest version pm. See attachment.... maybe this brings some more insight on this issue....

[jnb]

Hello Paulo,

The less images, the less this issue seems to be visible. In my mind, missing parts are likely to be extrapolated the same way, leading to a close result between the two versions.
But if I want this area to be fully reconstructed, I need to use more images, which lead to the previously mentioned problem.
Nevertheless, you can see on the depth maps that depth is not estimated on this area with the new method, whereas it is with the old one.

But I agree with you, the new mesh is really good and detailed, but on this spot, which is a shame !

[Mak11]

This is the most relevant information as JNB noted.
https://www.agisoft.com/forum/index.php?topic=13066.msg58741#msg58741

Some of the depth maps seem to be completely wrong.

BTW jnb.. Which GPU are you using?

Mak

[jnb]

Hello Mak,

Yes indeed !
 i7-7820HK and GTX 1070 SLI

[Mak11]

Jnb,

As a test. Did you try to reconstruct the mesh after disabling the depth maps that seem to be wrong (& keeping all the others obviously)?
Disable the photos then re-generate mesh with re-use depth maps option selected.

Mak

[Dano]

Hi,

you mention 1.7.3. It is not avalilable for download. Where do you get it from. Thanks.

[wojtek]

Hi,

you mention 1.7.3. It is not avalilable for download. Where do you get it from. Thanks.

https://www.agisoft.com/forum/index.php?topic=13045.msg58730#msg58730

[jnb]

I did not as this seems to have no impact on the concerned area. But still, this is a strange behaviour. The main issue here I think is the lack of depth information in this particular area of interest.
PM mark depth map method also seems to not take into account the bounding box.

I have uploaded my psx with both PM and SGM versions, tested with +- 70 and 35 cameras if someone wants to look at it : https://1drv.ms/u/s!Apz9qKkthJ4ywl8fYCfKLbMlbGi1?e=XuLJh2

Also, if this help to visualise the problem, here are some comparisons (heatmap and point) between SGM as reference and PM models (on +-35 cameras)