Volume render does not render

Hi all,

Volume render does not appear to work on my system (Ubuntu Trusty 14.04) since updating. Tracks appear just fine however.

All my dependencies are current and so it my graphics card driver. Any ideas?



OK, I’m assuming when you say updating, you’re not talking about upgrading from an earlier version of Ubuntu? Can you provide more details, specifically about your graphics card (make and model) and your drivers (open-source or proprietary)? You can find out via MRView’s info->OpenGL menu if needed.

Thanks Donald, that’s right, no system changes I can think of, only the most recent update of mrtrix3 performed today. It definitely worked with the previous mrtrix version. Perhaps its the drivers I use.


OpenGL version string: 4.4.13374 Compatibility Profile Context 15.20.1013

Drivers are from here (stable updates):

sudo add-apt-repository ppa:ubuntu-x-swat/x-updates
sudo apt-get install fglrx

OK, you’re running an ATI card with proprietary drivers. I do find ATI cards are pickier about things that nvidia… I’ve come across similar issues in my department, without ever finding the time to look into it properly. In the meantime, you could try setting NeedOpenGLCoreProfile: 0 in the config file, see whether that makes any difference…?

Also: any chance you could tell us when you last updated your installation? That might help us narrow down the issue.

Thanks Donald, the support on this free product is unbelievable, setting NeedOpenGLCoreProfile: 0 got it working.

I updated some point early last week and I noticed a lot of tearing in the volume image and then strangely I updated again today to try and fix the problem and everything had gone blank.

Only last week? That should be easy to narrow down, then. Did things work better before last week’s update, by the way? Did you have any tearing before that point?

Also, can I confirm that this happens before you’ve opened any tools, etc ? If you just open an image from the command line, immediately switch to volume render, nothing is displayed?

Yes, it was some point last week I think, certainly less than 2 weeks. When I open from command line and switch now I see the image but it tears (without the fix above):

You should know however I had not updated prior to this for a long time…

OK, thanks for the info. Unfortunately this is probably not going to help me all that much, since your previous install was also failing (although in different ways, but the underlying cause is likely to be the same)… We already have an issue open on GitHub about this, I’ll mention this topic there for future reference when we eventually find the time to fix it…