Just to confirm, can you try using some of the sample data (from the SampleData module) and confirm you see the same behavior as you do with your data? If so then it will be possible to easily reproduce and investigate the issues. We have the 'self test' feature in Slicer and it should be possible to create a scenario with 100 fiducials and then profile where the issue comes up.

Thanks for the quick reply! I tried it on the sample data set 'Pre-PostDentalsurgery' but had the same thing (also now using nightly build). Slow down becomes apparent around 40 point but scales quickly.

I have seen the slowdown with many points - I need to use a profiler to get an idea of where we might be able to speed things up.

Regarding the lack of an update when going from thin-plate to affine, you can trigger an update by selecting Similarity and back to Rigid. Can you check that?

Yes I did notice the Similarity - Rigid update trigger. Sorry I intended to say that the slowdown is present in both the affine and thin plate registration mode

Improvement implemented here:

https://github.com/Slicer/Slicer/pull/505

being tested.

Committed as:

https://github.com/Slicer/Slicer/commit/fe45f62d27d16852fca3b8f28b18ebe51d260840

Unless something goes wrong, tomorrow's nightly build should include these changes and it would be great if you could test them.

Unfortunately the nightly testing failed, so this will need to be backed out and we'll need to think if there's a better fix.

Hello Steve,

I noticed yes that is really too bad! Is there currently any outlook for a fix for this behavior because we are still very interested in using the module.

Best,
Johan

Found another thing to try - this is a localized change to landmark registration so there should be no side effects to the rest of Slicer.

Committed in r25172

Should be available for testing in tomorrow's nightly build if all goes well.

Fix effectively integrated in http://viewvc.slicer.org/viewvc.cgi/Slicer4?view=revision&revision=25173

Hello Steve,

Thanks for the update! Its working much better now. I still get a slowdown around 150 points where adding new points takes around 10 seconds. If a further speed up is not possible could I maybe try working on sets of 100 at a time and later add them together? Do you have some suggestions of how I could do this? Also I added a 'feature' issue to the tracker concerning the deletion of landmarks.

Thanks again,
Johan