November 2010 Archives

I compiled VTK and ITK libraries on both Debian and Archlinux machines.

On these machines I love to be clean and neat so: - all the software and libs installed by apt-get/pacman are in the dir /usr - all the libs and software manually compiled are installed in the dir /usr/local Sometime this introduces some path problems.

For example, installing manually Python packages, I found a "bad install directory or PYTHONPATH" error and a message like this:

"You are attempting to install a package to a directory that is not
on PYTHONPATH and which Python does not read ".pth" files from. "

It means that I'm going to install the Python package in a directory that is not in the search PATH of your Python system. The system looks for packages in /usr/lib/pythonX.X/site-packages but I'm going to install in /usr/local/lib/pythonX.X/site-packages.

In this case, I love the Python solution and so: - Create a file named altinstall.pth (or use the preferred file name just with the .pth extension) containing the code: import os, site; site.addsitedir(os.path.expanduser('/usr/local/lib/pythonX.X/site-packages')) - Put this site in your system python site-packages dir: /usr/lib/pythonX.X/site-packages

Now your Python know where are you new python modules! Clean and easy-to-maintain solution!

P.S

If you need add the /usr/local/bin to your system path follow the same idea and create a file in /etc/profile.d/ with the code: export PATH=$PATH:/usr/local/bin

Well, after compiling your VTK (with Python support) on a Debian (or Archlinux), you could receive an error similar to this form python interpeter if you import vtk module:

ImportError: libvtkCommonPythonD.so.5.7: cannot open shared object file: No such file or directory

This occurs because VTK installer puts all shared libraries in a subdirectory of /usr/local/lib Solve it by creating a file called vtk.conf in /etc/ld.so.conf.d/ directory. In this file, put the path to VTK libs, for example: /usr/local/lib/vtk-5.7/

And so, launch (as root) the command ldconfig to update the shared library path cache.

This is a clean way to solve the problem: avoid symbolic links, copy/paste files or setting mess-oriented enviroment variable as PYTHONPATH and LD_LIBRARY_PATH, please!

I received this link: http://git.marcansoft.com/?p=libfreenect.git It is a open source window driver for the innovative Microsofr Kinetic device. More details about this low cost device which will be a revolution for consumer experience here.

Anyway, no open source SDK is available, and I think the most valuable part of the Kinetic technology is in it.

The last week I was at the View Conference, the international computer graphics conference in Turin. Here I'm pasting some link that I collected during talks.

Software

• Alchemy: 2D creative drawing open source software. The idea behind the software is very cool.
• My Paint: Opens source clone of Auteodesk Sketchbook. Infinite size canvas, artist-centric user interface are the strongest ideas of this software.
• Gimp Animation Plugin: a plug-in for GIMP focused on animation. To try as alternative to Photoshop.
• 3Delight: RenderMan compliant professional render totally free of charge (also for commercial use). A good start before buying RenderMan. If you are a student or educator, any way, RenderMan licenses are affordable.

Books

• Snow Crash by Neal Stephenson. The book was cited by the [prof. Perlin] speaking about computer/human interfaces. You can find some futuristic ideas in this book.
• The hero with a Thousand Faces by Joseph Campbell. Tim Johnson refers to it as a fundamental book for storytellers. I agree.

Videos

• Magic Projection: innovative user interface in illusionism.
• What Matters to Me: concept video about the perfect futuristic user interface

And the website of the VFX italian artist Fernando Luceri who I met at View Conference: tons of smart and great tip&tricks for Blender user.