Closed curve constrained to model surface jumps to weird locations

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Mac OSX
Slicer 5.9.0-2025-04-25

I’m hoping to use a closed curve to make a new surface model from an existing model, but the closed curve behaves weirdly when I try to constrain it to the model surface.

Based on previous posts regarding the Dynamic Modeler module (for the eventual curve cut), my model has been decimated (0.5% reduction), the largest component extracted, and surface normals computed.

I then place a closed curve around a complex portion of the model. However, when I select to constrain the curve to the model, the curve jumps to other parts of the model.

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There are internal structures within the model. I tried making the model hollow using the Dynamic Modeler, but this did not stop the behavior.

Does anyone know why this may be happening? Thanks in advance for any suggestions or guidance!

2

It might be getting confused by nearby surfaces. Maybe use the modeler to make cropped cutouts of just the local surface of interest.

1 Like
3

Thanks, @pieper. I was hoping not to do the extra step of cutting the model before placing the closed curves, but you’re right that that is a good workaround!

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(photo to help anyone doing the same)