Issue with optimization

I am using Shapeworks with a new Bony labyrinth data and I am getting the same error when starting the optimization phase either with ShapeworksStudio or with python scripts.

(ERROR: ITK Exception: itk::ERROR: DataObject(0x7f34febcbe40): Attempt to sample at a point outside the narrow band: [0.491378, -1.8272, 4.29924]. Consider increasing the narrow band)

I am using Shapeworks 6.0.0 but I also tried the previous releases.

Any help would be very much appreciatedScreenshot from 2021-04-28 18-12-03


This usually means there is something unexpected about the data. For example, if the outer surface runs off the edge of the image. Would you be able to point us to a sample image from your data?

Hi Alan,

Thank you for your response.
Attached is a sample of the data.


(Attachment is missing)

Hi Claudia,

The source of the problem seems to be the very small image spacing of these images at 0.05x0.05x0.05. If I change the spacing of these images to something like 1x1x1 then it will run as is.

To use the data as-is, I needed to increase the <narrow_band> from the default of 4 to 5, but unfortunately, this parameter is not yet exposed through the Studio UI and must be set in the XML. If you are familiar with creating an optimization XML file, the parameter you will need will be:

<narrow_band> 5 </narrow_band>

Or, as I said, you can change the spacing of the images.

We will work on both exposing this parameter in Studio and in fixing the source of the scaling difference.

Hi Alan,
Thank you very much!
Changing the spacing to 1 solved the problem.