How to edit and crop 3D model with swift?

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Created May ’22

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How can I crop a 3D model as seen in the photos? Should I use MetalKit or can I handle it with sceneKit and modelIO? I couldn't find any code examples on this topic. Can you share the code snippet

Before: [https://i.stack.imgur.com/yDXXF.jpg)

After: [https://i.stack.imgur.com/m9ryg.jpg)

Answered by DTS Engineer in 713368022

You can create this functionality using either SceneKit or Model I/O.

In either framework, the general process would be as follows:

Define the cropping volume that you'd like to crop to (usually, this is a box)
Identify all vertices in the mesh that are contained in the cropping volume from step 1.
Create a new mesh using only the vertices identified in step 2. This is your cropped model.

Also, keep in mind that the approach described here is the "naive" approach. There are techniques to improve efficiency, but then the implementation gets more complex, and that's beyond the scope of what I'm willing to cover here. If you're curious, I recommend that you do some research on mesh boolean operations to see if you can find an efficient algorithm.

If you choose to use SceneKit, you would utilize SCNGeometrySource and SCNGeometryElement, so I recommend that you familiarize yourself with these classes.

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DTS Engineer OP

Apple

May ’22

Accepted Answer

You can create this functionality using either SceneKit or Model I/O.

In either framework, the general process would be as follows:

Define the cropping volume that you'd like to crop to (usually, this is a box)
Identify all vertices in the mesh that are contained in the cropping volume from step 1.
Create a new mesh using only the vertices identified in step 2. This is your cropped model.

Also, keep in mind that the approach described here is the "naive" approach. There are techniques to improve efficiency, but then the implementation gets more complex, and that's beyond the scope of what I'm willing to cover here. If you're curious, I recommend that you do some research on mesh boolean operations to see if you can find an efficient algorithm.

If you choose to use SceneKit, you would utilize SCNGeometrySource and SCNGeometryElement, so I recommend that you familiarize yourself with these classes.

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