Create a clean hole in my 3D model

[sonno]

I'm trying to create a clean hole/cut in my 3D model with cutting tools rectangular, circle or free.

Currently, when I cut the model, the edges of the cut are jagged and look like a sawtooth. I'm looking for a way to make a clean, smooth cut or hole in the model.

Is there a method to achieve this within Metashape? Ideally, I'd like to create a hole/cut with smooth edges, without the jagged or stair-stepping effect along a rectangular or free shape...

Kind regards,

[SimonBrown]

A polygon mesh is not going to resolve to a circular feature like what you find in a CAD model.

This sounds like a reverse engineering question? It's a two step process where the object is scanned a polygon mesh is created, and then the surfaces extracted to create planar or cylindrical CAD model surfaces that accurately describe geometry, like a cylindrical hole.

More here:

https://accupixel.co.uk/2023/11/09/reverse-engineering-photogrammetry/

CAD software does not easily resolve polygon meshes...hence the extraction step.

[Alexey Pasumansky]

Hello sonno,

Can you please give any screenshot with an example of the model and the part that you would like to cut?

How complex is the model's geometry?

[sonno]

Hi Alexey,

With older versions of metashape I would go through a dense cloud and cut in the dense cloud and then have the mesh calculated from the dense cloud and get a clean mesh on the edges of my cut. Now I calculate the 3D model directly with depth. But obviously in this case, with a model obtained from 2.5 aircraft photos, the mesh isn't as fine as some projects. when I make a hole/cutout in an area so that I can then merge another, thinner model in its place, I get jagged edges, the triangles of the mesh. The idea would be to be able to cut cleanly along a line or shape, recalculating other mesh triangles along the cut. I agree it's easier to write than to do!

[olihar]

Draw shape and use it to cut with.

[sonno]

Draw shape and use it to cut with.

Hello, can you explain how to do this? I draw a shape polygon on the 3D model but then I can't find an option in the latest version of metashape to cut  hole the model finely along it. In tools you can select points in the dense cloud with a shape, but for a 3D mesh model I can't find anything...

[olihar]

No you draw on the ortho or DEM to make a cut.

You can select outer or inner cut by right clicking and use this to dublicate your model.

Or you can draw the shape in the Model view, right click on it and set Boundary type to Inner Boundary and like above use it to duplicate your model.

[sonno]

No you draw on the ortho or DEM to make a cut.

You can select outer or inner cut by right clicking.

My request for assistance concerned the possibility of cutting the 3D mesh cleanly. So you're confirming that you don't know how to do it either ?

[Alexey Pasumansky]

Hello sonno,

If you are working with the latest release version (2.1.3) of Metashape, then you can draw the shape in the Model view, like olihar mentioned above, right click on it and set Boundary type to Inner Boundary, then right-click on the model's label in the Workspace pane, choose "duplicate" option and in Duplicate Model dialog enable "clip to boundary shapes" option.

Then if you are happy with the result, you can remove the original model from the project and leave only the duplicated copy with the proper hole with the straight edges.

[olihar]

No you draw on the ortho or DEM to make a cut.

You can select outer or inner cut by right clicking.

My request for assistance concerned the possibility of cutting the 3D mesh cleanly. So you're confirming that you don't know how to do it either ?

What do you mean I do this all the time. This is how you do it, I am Alexey have both explained to you how to do it.

[sonno]

What do you mean I do this all the time. This is how you do it, I am Alexey have both explained to you how to do it.

ouarf, you are "olihar".

[olihar]

What do you mean I do this all the time. This is how you do it, I am Alexey have both explained to you how to do it.

ouarf, you are "olihar".

What does that even mean?

[sonno]

you're not Alexey but Olihar and Alexey understood my request and my problem and gave a detailed answer to my question. kind regard

[olihar]

you're not Alexey but Olihar and Alexey understood my request and my problem and gave a detailed answer to my question. kind regard

Yes with an explanation quoting my name as the explanation.

then you can draw the shape in the Model view, like olihar mentioned above, right click on it and set Boundary type to Inner Boundary,

[sonno]

yes, but you didn't explain anything in detail. your speech was unusable.