Trouble aligning chunks

[mansouraoun]

Hello everyone,

I'm asking for your help since I can't seem to find a solution to align the two chunks of my object. In my case it's a flat piece of brick. I tried capturing the object in many ways and failed to have a 360 degrees cover of the object. The most effective way I found online for flat objects (specially stones) was to capture them in two series, one time on its head fixed in clay, and the other on its bottom. I got the best results from that technique yet metashape can't seem to read the two chunks as part of the same object and auto align them, knowing that there's enough overlay for that.
I attached the pictures of the two chunks.

I have the standard licence, so I can't use markers to manually align them, which means that I have to rely on the auto-align in the standard version.
What can be done to solve this problem? or is there better workflow for my case?

Thanks a lot!

[jenkinsm]

Hello everyone,

I'm asking for your help since I can't seem to find a solution to align the two chunks of my object. In my case it's a flat piece of brick. I tried capturing the object in many ways and failed to have a 360 degrees cover of the object. The most effective way I found online for flat objects (specially stones) was to capture them in two series, one time on its head fixed in clay, and the other on its bottom. I got the best results from that technique yet metashape can't seem to read the two chunks as part of the same object and auto align them, knowing that there's enough overlay for that.
I attached the pictures of the two chunks.

I have the standard licence, so I can't use markers to manually align them, which means that I have to rely on the auto-align in the standard version.
What can be done to solve this problem? or is there better workflow for my case?

Thanks a lot!

Did you delete all of the unnecessary points (the clay etc) before aligning the two chunks? Leave enough overlap for the software to align similar points, but definitely get rid of any unwanted points before aligning.

This is explained here: https://www.youtube.com/watch?v=PYEBND8eTZY

[mansouraoun]

Thanks for the reply.
Actually I didn't try removing the clay because I was following this tutorial where the person aligns them with the clay parts still on. https://www.youtube.com/watch?v=qKWjPNlRK_I&list=LL&index=10&t=499s&ab_channel=SamScansStuff
I know the tutorial is a bit old but I said if the 2015 version of the software can do it, surely metashape 2021 can do it, but maybe it doesn't work like this anymore.
I'll try to follow the tutorial you suggested, thanks for the recommendation.

[Alexey Pasumansky]

Hello mansouraoun,

I would rather suggest a two step approach:

1. Put top and bottom images to separate chunks, align the photos in each chunk and generate rough models (from tie points or low quality depth maps). Then cut from the generated models the clay holding the actual object of interest and generate the masks from the model.

2. After that drag and drop images from the original two chunks to the newly created empty chunk (this allows to move the masks as well), you can do it in the project copy to keep the initial results. Then run  Align Photos procedure in the joint chunk using Apply Mask to Key Points option. And then proceed to the further reconstruction stages (for example, Build Mesh from the depth maps source and apply the texture).

[mansouraoun]

Hello Alexey,

Thank you so much! That worked like a charm!
I attached pictures of the final result.

Best,
Mansour