Bad renderized image windows on Linux

[C. Sonnenstein]

Hi,

Every visual change in a image window (Undo and Redo functions also) are bad renderized (like a bad-sintonized TV) during some seconds.



The machine is a Intel Core 2 Quad Q8200 @ 2.33 Ghz, 8 Gb RAM and nVidia GeForce 8600 GT, running PixInsight Core 01.05.09.0561 on Fedora 11 x86_64 distribution.

[Niall Saunders]

Wow, that isn't a bug - that is a 'disease' !!!

[Cheyenne]

I would suggest taking a look at some of your X11 settings, in particular composting, DRI, etc.

[Juan Conejero]

Hi Carlos,

Phew! this one is, how to say, nice

Seriously now. I haven't seen something like this before. Two possible causes come to my mind:

- Invalid/inappropriate/suboptimal graphics driver. I suppose you're running the default graphics driver that comes with Fedora. I strongly recommend installing an up-to-date graphics driver from nVidia.

- Wrong X configuration. As Cheyenne has pointed out, this may be due to some messing with your X settings. Installing an up-to-date driver would fix this too.

The required procedure to install a new graphics driver in Fedora is relatively simple. Below is the step-by-step procedure. Please make sure you understand all the steps before starting it. Also make a backup copy of your data before installing a new graphics driver —there is actually no risk at all if you follow all the steps correctly, but making a backup is always a good advice so here it is.

1. Keep your system up-to-date. In particular, you must have the latest kernel installed:

Code: [Select]

su -c "yum update kernel"
2. Install the kernel development package for your current kernel version:

Code: [Select]

su -c "yum install kernel-devel"
3. Download the latest certified graphics driver for your nVidia card. As of writing this, your driver is 190.42:

http://www.nvidia.com/object/linux_display_amd64_190.42.html

4. Reboot your computer and log in as root.

5. Exit X. This can be done by switching to execution level 3:

Code: [Select]

init 3
6. Now you have a nice text-based terminal console that asks you to log in. Your adrenaline is pumping high, but don't panic. Log in as root.

7.  Change to the directory where you downloaded your graphics driver in step 3. As you were a regular user, it probably is in that user's Download folder. For example, assuming you were "carlos" when you downloaded the driver, and that you downloaded it with Firefox in a default configuration:

Code: [Select]

cd /home/carlos/Download
Otherwise please use cd with the appropriate directory where you have the driver installer file.

8. List the directory contents to make sure you have the driver installer there. For example:

Code: [Select]

ls -l
Your driver installer file should be something like: NVIDIA-Linux-x86_64-190.42-pkg2.run

9. The driver installer is an executable file, but it probably doesn't have execution permissions set at this point. Make sure you can run it by entering this command:

Code: [Select]

chmod +x NVIDIA*run
10. Execute the driver installer:

Code: [Select]

./NVIDIA-Linux-x86_64-190.42-pkg2.run
11. If all goes well, the installer will compile its kernel module, install it, update your OpenGL configuration, and tell you it was installed successfully. Say yes when it asks you to install a 32-bit compatibility OpenGL module.

12. You're done! Now reboot your machine:

Code: [Select]

reboot now

Now each time you update your kernel, you must repeat steps from 5 to 12. Step 2 shouldn't be necessary if you have automatic updates enabled. Otherwise, the kernel development package must be manually updated along with each new kernel version.

Hope you'll have no problems. If somebody thinks I've made a mistake in the above procedure, please post it!

[C. Sonnenstein]

Juan, Cheyenne, thanks for your help.

I can't understand why the same kernel had no problems running previous PI releases.

[Cheyenne]

There is a note in the list of new features for the 1.5.9 release

Platform-Specific Notes

On Windows and Mac OS X, the new floating previews work without flaws. On Linux/X11, compositing extensions must be installed and running on the X11 server; otherwise the transparencies will not be rendered (instead, opaque windows will be used, which work but are ugly). Compositing extensions are enabled by default on all modern Linux distributions running on reasonable hardware, so this is not a practical problem.

So if you compositing was disabled you might have grief