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Author Topic: How does Metashape determine the orientation of the final model?  (Read 708 times)

bgreenstone

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How does Metashape determine the orientation of the final model?
« on: September 02, 2021, 06:50:46 PM »
I use Metashape for creating 3D scans of small objects that I photograph on a table.  It works incredibly well, but the orientation of the final model is always some random, crazy orientation.  Obviously, the software doesn't know which way is "up" from a set of photos, but I'm wondering what criteria it used to determine the orientation?  Is there anything I can do to help it come out so that the tabletop, ground, or whatever is actually flat and parallel with the X/Y plane?

-Brian

Paulo

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Re: How does Metashape determine the orientation of the final model?
« Reply #1 on: September 02, 2021, 07:15:12 PM »
You could just place 3 markers on base plane of table and set their reference Z to 0, set marker's accuracy to 10/10/.01, measure each marker in at least 2 photos and update. Your model will then be leveled wth base plane Z set to 0....

Better even would be to print 3 coded markers and paste them to the table... This way the markers could be automatically detected by Metashape....see Coded targets in workflow section from Metashape User Manual...Measure the distance between 2 markers and use this distance to also scale your model...
« Last Edit: September 02, 2021, 07:33:13 PM by Paulo »
Best Regards,

Paul Pelletier

CheeseAndJamSandwich

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Re: How does Metashape determine the orientation of the final model?
« Reply #2 on: September 03, 2021, 05:40:54 AM »
I have always seen this too...

But alas, i only have Metashape Standard...  I'm doing scans for free for our community, so simply can't afford $3,499...  :'(

Could it be possible that MS Standard could have a small subset of the reference features of Pro?
Could MS-Std. have, say, 3, 4 or 5 markers?
This would be enough to get the model orientated correctly, and perhaps correct some dishing if present? (i've been lucky and not experienced it yet).  And perhaps scale it to a basic degree...

I'd love to be able to set the -z/depth of my underwater scans, relative to the x,y grid.

Cheers.
« Last Edit: September 03, 2021, 06:12:40 AM by CheeseAndJamSandwich »

bgreenstone

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Re: How does Metashape determine the orientation of the final model?
« Reply #3 on: September 03, 2021, 05:55:03 AM »
I only have Standard as well.  Are markers only supported in the expensive version?

I'm actually hoping to find an automated way to deal with this since I always just run my photos thru a Batch that I have setup. 

-Brian

CheeseAndJamSandwich

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Re: How does Metashape determine the orientation of the final model?
« Reply #4 on: September 03, 2021, 06:18:28 AM »
I only have Standard as well.  Are markers only supported in the expensive version?
I believe so yes...   :'(

Surely we could have some basic features to help with this? ...without stepping on the feature set that the super wealthy resources/government/infrastructure people use for surveying their multi-million dollar projects...

bgreenstone

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Re: How does Metashape determine the orientation of the final model?
« Reply #5 on: September 03, 2021, 06:22:25 AM »
One interesting thing is that I use the Orthophoto texture mapping mode which basically just projects the texture straight down the model's z-axis.  This implies that Metashape knows which direction is straight down relative to the mesh, therefore, it should be able to align the object as well. 

-Brian

Kiesel

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Re: How does Metashape determine the orientation of the final model?
« Reply #6 on: September 11, 2021, 04:48:37 PM »
Even it isn't possible to set orientation in Metashape Standard accurately, you can set it approximately by using the 3 projection buttons. "7" for top down view, "1" view from left and "3" view from right and use the rotate object button until all projections look right to you.

If you put some markers and /or scale bars measure and capture them in your scene, you can export the final model and scale and orient it in external applications like Meshlab or CloudCompare.

Hope this helps.

Kiesel

CheeseAndJamSandwich

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Re: How does Metashape determine the orientation of the final model?
« Reply #7 on: September 12, 2021, 02:45:39 PM »
Indeed.  I've been using the '1, 3, 5, 7 + grid set to meters' trick for a while.
it's fairly easy to do.  And if you spend a bit of time, you could scale it fairly accurately.

But it'd be nice to have, say, 3 markers I could place and get it to just jump into the correct position and scale.