How to specify voxel size for Simple Neurite Tracer

I’m using the Simple Neurite Tracer to analyze nerves in OCT images. Is it possible to specify the size of the voxels to obtain correct measurements for path lengths? I see in the documentation of the .traces File Format that there’s a tag <samplespacing> that should do what I need, however, I don’t see a way to set the same information in the GUI.

SNT reads that information from the image metadata. You can set it in IJ under Image>Properties…. You should subscribe to the Neuroanatomy update site to access the latest SNT version, that has several metadata handling improvements (release notes). SNT’s rewrite was quite bumpy, but it is finally done, although it will likely take a couple of months until it is distributed through Fiji’s default update site.