MRview ROI editor bug - Mask removed

Hi everyone,

I am having some issues with MRview ROI editor. I am trying to edit (edit mode) a previously generated mask with the brush pencil. However, when I try to paint or erase a few pixels, the current slice of the mask gets removed.

I am using mrview 3.0.3, 64 bit release version, built Jul 19 2021, using Eigen 3.3.9. My system is a MacOS Big Sur 11.4. As an additional note, our team has another Big Sur system suffering the same problem with Mrview with the same 3.0.3 version.

Thank you so much!

These systems aren’t using the latest ARM CPUs, are they? These issues sound similar to problems reported for the M1

I am unsure about that. I have the same problem using the pre compiled binary, the conda version, and even I installed mrtrix3 compiling it from the source files, which required to apply the method described in Support for arm64-apple · Issue #2247 · MRtrix3/mrtrix3 · GitHub to be able to ./configure.

Is there any update on the support for new macOS arm64-apple systems? Would it be possible to downgrade to any version to avoid this bug?

Thank you so much

No, if you have an arm64-apple machine, you WILL be affected by this bug regardless of which existing MRtrix version you use (even if you would use a precompiled intel binary…) because the problem stems from the calls we make to the OpenGL library (which are the same calls for each platform).

The problem arises either because:

  1. There is a bug in Apple’s OpenGL implementation for M1. In this case we have to hope that Apple fixes their OpenGL implementation, or we have to work around the problem.


  1. We are using OpenGL in a way that is not cross-platform, but this has not caused issues so far, because the OpenGL implementations were not that different. This might no longer be the case for Apple M1. In this case we need to fix it…

So you will have to hang in there until Apple or we can sort it out, I am afraid…

If you are not sure whether you are using an M1 mac, Click the Apple icon in the top left, and then “About This Mac”. If you see any mention of “M1”, you are using an M1 mac…