CFD Online Discussion Forums - Black output screen but geometry present

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- - Black output screen but geometry present - Ubuntu 14.04 (https://www.cfd-online.com/Forums/engrid/168201-black-output-screen-but-geometry-present-ubuntu-14-04-a.html)

Black output screen but geometry present - Ubuntu 14.04

Hey all,
I recently installed Engrid and I got no problem with installation however when I import an STL file (from damper tutorial) or egc (from Heat exchanger) I get a black output screen.
From the damper tutorial I get the surface cells present and can even see that check surface integrity tells me that the mesh is ok.
I have also tried to import the mesh in paraview and see nothing when i go from engrid but when i open it seperately i see the stl images.
The Output file in the tmp folder is shown in figure 2 and the terminal output is shown in figure 3.

Any help would be greatly appreciated.

Quick questions:

Which version of enGrid have you installed?
Which installation instructions did you follow?

Thanks for the reply.
I have installed engrid 1.4. Using the instructions available on https://github.com/enGits/engrid/wik...D-Installation for a Ubuntu system.

Greetings Shivaang,

In a terminal/console window, from within the folder "engrid/src", please run the following commands:

Code:

ldd engrid > log.ldd.engrid

gzip < log.ldd.engrid > log.ldd.engrid.gz

Then please attach the file "log.ldd.engrid.gz" to your next post. This will give us a clear detail of which OpenGL library it's linked to.

And few more questions, to help diagnose the problem:

Are you running Ubuntu inside a virtual machine?
If you are, then:
1. Are you using 3D acceleration?
2. Which virtualization software are you using? Examples: VirtualBox or VMPlayer.
If you are running in a real machine, did you install the drivers for the graphics card?
You mentioned ParaView. How exactly did you install it?

Best regards,
Bruno

Hey Bruno,

I have ran the commands that you mentioned and attached the output.
My machine's operating system has inbuilt Ubuntu (so not a virtual machine)
My drivers are installed- Checked this by glxgears command and also have checked that direct rendering is active.
For paraview I installed it using the instructions provided on the Openfoam.org website:

Code:

sudo apt-get download  paraviewopenfoam44  --allow-unauthenticated 

sudo dpkg -i paraviewopenfoam44_0-1_amd64.deb 

sudo apt-get install qt4-dev-tools 

sudo dpkg -i paraviewopenfoam44_0-1_amd64.deb

Thank you for the support, I really appreciate it.
Regards,
Shivaang Sachdeva

Hi Shivaang,

Mmm... from the log file that you attached, it indicates that it's linked to the Mesa OpenGL library:

Code:

libGL.so.1 => /usr/lib/x86_64-linux-gnu/mesa/libGL.so.1 (0x00007fd46514d000)

OK, then let's check how ParaView is linked to OpenGL. Please run the following commands:

Code:

ldd /opt/paraviewopenfoam44/lib/paraview-4.4/libvtkftgl-pv4.4.so > log.ldd.paraview

gzip < log.ldd.paraview > log.ldd.paraview.gz

You can run the commands anywhere you like, for example in your Desktop folder. Then please attach the file "log.ldd.paraview.gz" to your next post.

For example, I got the following:

Code:

libGL.so.1 => /usr/lib/fglrx/libGL.so.1 (0x00007f64249c7000)

Which is for the AMD/ATI driver I have in my machine.

Best regards,
Bruno

Hey Bruno,
The paraview seems to be linked to the same place from the file generated (shown in attached).
In the engrid linking file that i created, I got the following code, could this be the problem?

Code:

        

libengrid.so.1 => not found

libng.so.1 => not found

Regards,
Shivaang

Hi Shivaang,

OK, at least both are using the same OpenGL library.

I've compared with a build I made within a VM that has Ubuntu 14.04 and this was different:

Code:

libdrm.so.2 => /usr/local/lib/libdrm.so.2 (0x00007fd45c2b2000)

This is usually also associated to the graphics card drivers. Both ParaView and enGrid are reporting to be linking to these two, so that shouldn't be a problem... at least I hope not.

Quote:

Originally Posted by shivaang (Post 591846)

In the engrid linking file that i created, I got the following code, could this be the problem?

Code:

    

libengrid.so.1 => not found

libng.so.1 => not found

That's only because the libraries aren't visible on the path, unless we use enGrid's starter/launch script. This shouldn't be a problem, but you can double check this by doing the following command from within the "engrid/src" folder:

Code:

export LD_LIBRARY_PATH=./libengrid:./netgen_svn:$LD_LIBRARY_PATH

then you can do the ldd command once again.

The weird part is that I have the very vague idea that I've seen this happen in the past, but I can't remember what keywords I should be looking for...
The only thing that I can remember right now is that you can try the following:

Quote:

Originally Posted by preichl (Post 279104)

Setting the environment variable via the command below worked for me.

export LIBGL_ALWAYS_INDIRECT=y

Run this last command before you start running enGrid.

The other thing you might want to try is the following two commands:

Code:

wmUNSET

engrid

And then try importing again the STL file.
The wmUNSET command is an alias for unloading the OpenFOAM shell environment, so hopefully this will unload any potentially conflicting environment variables!?.

Best regards,
Bruno

Hey Bruno,
I have followed the instructions however it doesn't resolve the error. The command to fix the visibility of the library did work on the bright side.
The other codes did run however the stl file is still not visible.
I am not sure but whenever I export a geometry it is called "Operation 0" and when i perform the surface integrity it says that the operation is deleted "deleting Operation 0x1da8250". Could this be relevant?
Would it be advisable to download some other graphics card software?

Regards,
Shivaang Sachdeva

Quick answers:

Quote:

Originally Posted by shivaang (Post 591860)

"deleting Operation 0x1da8250". Could this be relevant?

That's only an information for the developers. It's a debug-related message, stating that the operation is complete and the respective object that did the operation has been deleted (or at least it should have).

Quote:

Originally Posted by shivaang (Post 591860)

Would it be advisable to download some other graphics card software?

You can try and update the drivers for the graphics card.
If you're using an Intel graphics unit (possibly one that is embedded within the CPU), you might be using one that has a faulty OpenGL implementation :(

I was looking for threads about Intel cards and this one popped up: http://www.cfd-online.com/Forums/ope...14-04-a-3.html - do you have the package "libglu1-mesa-dev" installed in Ubuntu?

edit: The other possible solution is to disable the 3D accelerated desktop feature that Ubuntu usually has turned on by default.

Dear Bruno,
Thanks for the assistance and sorry for the late reply. I actually was having some difficulty with the installation of new drivers (unsuccessful), my OpenGL version was mesa10.1.3. I am currently updating my system to ubuntu 15.10 and hopefully that will be able to resolve the issue. I searched for the libglu1-mesa-dev and saw that it was present and working, so it was not the issue. As for d accelerated I tried turning it off but it was not able to resolve the issue. I will try installing it with Ubuntu 15.10 and hopefully the issue will be resolved.
Thanks for the help and I will post if it resolved the problem.

Regards,
Shivaang

The issue has been resolved by updating to Ubtuntu 15.10. I am not sure whether that is the ideal way to resolve the issue. But I would like to say thank you for the assistance.