Mesh process doesn't create enough triangles

PIX4Dmatic
1

Hello,

I have problem where I want to create large area mesh with 50M triangles but it only has ~10M triangles. I made smaller test area which is 1/20 of the original and set max triangle count to 5M and it was created successfully. Test area is not more complex than rest of the large area.

I want to know why doesn’t the larger area which is running same settings create 50M triangles? I have tried setting smoothing off and deghosting weak/strong but didn’t help.

2

Hello,

Thanks for reaching out. The max triangles settings is an upper cap that is used during mesh decimation/simplification. Can I ask which template are you using? If you are using Pix4Dcatch template you can try to switch to the “Aerial” or “Thin structure” template that have settings that can produces higher number of triangles. Please don’t hesitate to reach out.

Regards

Greg
R&D Manager

3

Hi,

I use “Aerial” for both the large and the test area. I’ll test “Thin structure”.

I am still baffled how the Large area mesh has less triangles compared to Test area when they are run with same processing parameters.

Also noticed that putting “Region of interest” on half of the Large area and processing mesh, created a mesh with a higher triangle count that when processing whole Large area.

4

@gregoire.krahenbuhl Tested “Thin structure” template with mesh but it didn’t produce higher triangle count.

I understand that max triangle count is an upper cap and not a triangle count that mesh will always have.

I don’t understand why processing the test area and the large area with the same settings produces less triangles for the large area. Even if I were to process both with 100M triangles.

5

Hi Antti,
Yes I agree that this is neither intuitive or ideal. The technical answer is that it has to do with how the space is discretized in the mesh generation algorithm which depends on the scene size. We are working on improving this however. If you are able to share with me your project we can take a closer look at it specifically. Thanks

Greg
R&D Manager

6

@gregoire.krahenbuhl Unfortunately I’m not able to share images used in this project. If this problem persists across other projects and I have data I am able to share, I’ll be in touch.