Now you want to create fantastic 3D animations using free software. You know RenderMan and its BMRT implementation, you have experimented with Moonlight, AC3D and Mops. And yet couldn't find any useful tool for animation - you can create even complex scenes, but what about movement?
Screenhack offers an answer to this question. It's a program for moving static RenderMan objects along trajectories defined by formulae. It's very simple to use and yet powerful and efficient. It's GPL-licensed.
It was written in May 2000 by an Australian programmer, Michael Wouters, who then started working on a GUI version and discontinued development of the command line version of screenhack. Because I like the program a lot and use it quite often, I decided to add some features I miss.
In the future, I want to integrate mesh deformation procedures. I don't mean this can be done manually ;) Rather, key frames will have to be exported subsequently from a modelling program and screenhack will fill in secondary frames. This should, of course, be integrated with current infrastructure - controlling modifications with f(t) functions. And I thought also about shader modifications - this should be relatively easy.
If you are accustomed to programs such as Lightwave, where movement is controlled by graphical controls, you may find screenhack a little cumbersome, but in fact after some time you may wonder how you could have lived without it ;) If it's too difficult to visualise movement looking at the equation, you can experiment with curves using program geg (GTK+ Equation Grapher - some of its code is in screenhack too).
How to create mpeg movies using BMRT and screenhack
(Very bad actually. It's meant to encourage you - when you do something nice, please send it to me and I will put it here :))
You can reach me at arturs@linuxpl.org.