digital home of MacSlow

The addition of anti-aliasing to my GLSL-based raymarcher (part of ToyShader) does result in cleaner visuals as expected (see image-sequence below), but the performance-hit is considerable (especially on my laptop’s intel HD4000 GPU). Before this can be enabled by default, I need to implement over-relaxation of the raymarching-steps. This allows to traverse the view-ray for each (sub-) pixel in larger steps – compared to classic raymarching/sphere-tracing – resulting in a considerable speed-up. The paper “Enhanced Sphere Tracing ” by Keinert et al. introduces this improvement among other enhancements with regards…read more

Zoom baby, zoom! When doing shader-programming a “Hello, world!”-equivalent I always considered to be an implementation of a zoom into a mandelbrot-set. And so I did… and for “just because I can”-reasons, I also wrote a GLSL-environment very much like the WebGL-based ShaderToy.com, so I can also have these as local and native shader-hacks on my desktop. Getting the browser out of the equation saves about 15% of system-load. Here is the example as WebGL-version on ShaderToy and you’ll be able to get the same on your desktop as a…read more

Time-killer WebGL There are a lot of shader-playgrounds for WebGL scattered around the net. A few of the better known ones are… Shadertoy GLSLsandbox Shdr WebGLPlayground GLSLbin Some let you mess around with the fragment-shaders only, while others expose vertex- and fragment-shaders. The great advantage you get with these WebGL-environments is the fact, that they eliminate the need for setting up your OpenGL-context using the native toolkit of your OS, though this is only mildly painful these days thanks to SDL, Qt and gtk. Thus you can concentrate on the…read more

… by the developments around the crisis of Crimea and what Europe is currently tumbling towards! It feels like the Cuban crisis from 1962, as far as I can tell from having read about it in history-books. Thankfully back then it didn’t end in a catastrophe. Years later I was born. That’s something I could not influence. But now that I’m here, I’d like to keep it that way for several more decades. You can be sure I’ll do what I can to influence that! Besides me there are many…read more

… thus eMail became unusable for me. In the logfile imapfilter writes, I have tons of “BAD UID not allowed now”-messages. Trying to research on the web about this error, did not result in any worthwhile hints, which would help to fix the problem. Because of this imapfilter-malfunction, I already missed two important eMails due to that!  

Phew, finally I’ve a digital home again on the net. I’ve lost my old blog macslow.thepimp.net long ago and was too lazy (or rather too busy) to move beyond the simple placeholders that are my current Google+– and Facebook-accounts. I don’t really like these social networks too much. So what to expect here? My usual daily, weekly or monthly ramblings about computer-science, sports and motorcycles… and everything else that might cross my mind or I find interesting. It’s a blog after all 🙂