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Author Topic: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated  (Read 555 times)

SP74

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Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« on: April 29, 2019, 03:39:14 AM »
Hi,

I have a very large 3D modelling project for a mine site survey.  I have broken the project into a large number of sub-chunks, and generated dense clouds.
The dense clouds have been exported, where I have used a Poisson filter to perform a "smart" decimation of the point cloud.  The objective is to significantly reduce the point cloud density then re import the point cloud to Metashape for meshing etc in a reduced time frame.

I have successfully exported, filtered and re imported a dense cloud.  However when I generate a mesh from the Dense Cloud based on an Arbitrary surface type, with a High target face count, I am getting a very low resolution result, with 159K faces when the target was 4.7M faces.  If I generate the mesh using an Height Field surface type, I get the correct face count of 4.7M faces. 

I have attached screen shots of the resulting meshes & the input point cloud.

Cheers,

Stu.

wojtek

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #1 on: April 29, 2019, 12:40:17 PM »
I have the same experience, any imported/edited cloud ends up with 1/10th of the mesh density than it should.

Alexey Pasumansky

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #2 on: April 29, 2019, 02:15:09 PM »
Hello Stu and wojtek,

Have you tried to use Custom face count value that is higher than the suggested by High preset? Does it still result in the considerably lower polygon count?

Best regards,
Alexey Pasumansky,
AgiSoft LLC

SP74

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #3 on: April 30, 2019, 06:10:15 AM »
Hi Alexey,

I just tried a custom face count of 10 million faces and it yielded exactly the same face count as I am getting from the High setting.

Custom Face Count = 10,000,000
Actual Face Count = 159,211

High Face Count = 4,773,856
Actual Face Count = 159,211

Cheers,

Stu

wojtek

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #4 on: April 30, 2019, 02:02:43 PM »
Yeah, same results here.

uclement

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #5 on: September 09, 2019, 12:43:58 PM »
Hi fellows

I'm facing the same problem... Did you found a solution?

Thanks & cheers

Alexey Pasumansky

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #6 on: September 09, 2019, 01:03:53 PM »
Hello uclement,

Please specify the workflow steps that you are following. If you are re-importing the point cloud, how many points are there in the imported cloud.
Best regards,
Alexey Pasumansky,
AgiSoft LLC

uclement

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #7 on: September 09, 2019, 01:51:18 PM »
Hi & thanks for your answer Alexey

I've aligned 30 aerial images with 100MP resolution, measured GCPs, optimized the cameras and built a DenseCloud on default High settings. I've exported a part of it (defined by the region) and imported this partial cloud with 4'073'236 points into a duplicated chunk.
When i build the Mesh it estimates approx. 800'000 faces on High but i end up with only 3'324 faces. I tried a custom face count but no matter how much i specify i end up with the same 3'324 faces.
Edit: i tried resetting the region to the full extend of the aligned images as well as limiting the region even a little more on the area which is covered by the imported dense cloud.

I have added screenshots showing the imported dense cloud and the processed but "failed" mesh.

Regards
Urs
« Last Edit: September 09, 2019, 01:53:58 PM by uclement »

Alexey Pasumansky

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #8 on: September 09, 2019, 04:31:40 PM »
Hello Urs,

Can you please send the log from the Console pane related to the mesh generation operation that produce the described results? Starting from the task parameters definition till the final processing line.
Best regards,
Alexey Pasumansky,
AgiSoft LLC

uclement

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Re: Arbitrary Mesh from Imported Point Cloud - Heavily Decimated
« Reply #9 on: September 09, 2019, 05:35:40 PM »
Hi Alexey

You find the log in the attachments. I tried all interpolation modes as well as various ex- and import formats.

Thank you!
Regards
Urs