Multicam system: textures from one slave cam have artifacts but align. is correc

[ilia]

Hi,

I have a quite weird issue related to multicamera system. I was using a camera with 6 synced modules. Meshing went really well, but textures had visible artifacts. I've tried to narrow down by simplifying the mesh and throwing away more and more cameras and ended up with a single multicamera, simple mesh and the same issue.

One of slave cameras despite having a proper relative orientation estimation to master camera doesn't provide nice textures for part of its view. Some polygons in the view of this slave camera are properly textured (and for texturing this slave camera is used as no other cameras see these polygons), but other polygons just have a weird splat of single color.

Here is the project uploaded to GDrive with the data:
https://drive.google.com/drive/folders/1iV6ubNF6bi8TzZXByRm-VK4u4704lhds?usp=sharing

I suspect here a gimbal lock issue. Two angles of slave offset angles for this camera are close to 180.

I will try to roll this camera data 180 degrees to see if the problem disappear. This didn't help.

Metashape 2.0.3, also tested with 2.1.1 and got the same issues. Windows 10, RTX 4090, driver  536.99.

[ilia]

This getting stranger and stranger.

I select using Python commands just a single image in two rigs. And as the result I see the attached image, where some part of the mesh is textured despite the fact that is is behind both cameras which are on.
Another thing (attached images v2 and v3) is that somehow black area of non-visible part of the mesh cripples into nicely visible part and getting mixed with it. This is the second image I attaching to this post.

So it leaves a blurred stripes as on this column. I'm also attaching the two screenshots showing a single active images from two rigs to show what is visible and what is not.

Metashape version: 2.0.3, build 16960, x64 Win.

[ilia]

And the latest observation -- I did the same project but without cameras being locked down in a rig and everything went good. Mesh was slightly worse (due relaxed constrains I guess), but no issues with texturing.

[ilia]

Latest update -- no problems if switch off GPU texturing and use CPU for texturing.

[Alexey Pasumansky]

Hello ilia,

Seems that the problem could happen when NVIDIA GPU was used for the texture blending, but in the version 2.1.1 this problem should be resolved:
https://www.agisoft.com/downloads/installer/

So you can try texturing using the same parameters via GPU enabled to see, if you get same result as when only CPU is used for texture generation.

[ilia]

Hi Alexey,

I think the problem is still here even with 2.1.1 version.
I've tried to run it again with and I see blurred stripes on the texture. I'm attaching screenshot of the same module textured with the same camera with CPU and with GPU.

Driver 555.61.
As a I guess: This driver comes with 12.4, but I have other CUDA versions in my path. Can it be related somehow?

[Alexey Pasumansky]

Hello ilia,

Is it possible to share this project with mesh camera used to support@agisoft.com (other cameras can be removed to reduce the project size)?

And please confirm that you are using 2.1.1 build 17803.

[ilia]

Alexey,

Sorry, when I was downloading the new version I accidently downloaded Standart one. So when I run professional one it was still the old one.
Now with 17803 build I have it resolved without such artifacts.

[Alexey Pasumansky]

Hello ilia,

Thank you for the confirmation, glad to hear that latest version resolves the problem for you!