digital home of MacSlow

A brief update on one particular thing cooking in my laboratory at the moment… I’m taking a break from offline 3D-graphics (my path-tracer BeamRacer) to implement my own version of cubical marching squares (aka: CMS) for a stand-alone visualization library, which has to be named still. The versions of marching-somethings I’ve seen outside of academic-paper implementations – in commercial applications in particular – are not very pleasant to look at. Only the games-industry manages to produce clean and elegant visuals, but lacks data-visualization details and precision on the other hand…read more

… yes that venerable old desktop-toy from years ago, has finally found a new permanent repository-home again… after enough people poked me about it. I also updated the related project-page on launchpad. In the early days it used to live on people.freedesktop.org/~macslow/cairo-clock (or something like that). Thanks to the wonders of git the whole commit-history is still intact. Looking at that code-base makes me want to redo it all… or update the build-system (CMake or Meson) and move to gtk+ 3.x at least. But maybe someone beats me to it…read more

Over the last few weeks, I’ve added new shaders to ToyShader. Among the most impressive ones is an interactive 3D-fractal. This shader implements the typical iterative term z = z² + c, but with quaternions instead of the usual complex numbers. Since quaternions are 4-dimensional vectors, one has to cut a 3D-“slice” out of the 4D-body in order to get something meaningful to the screen. Tweak the components of c and you will get different 3D-slices. That’s what’s making this funky animation possible… apart from moving the camera around with…read more

I’ve added a new example to ToyShader, which does three-dimensional perlin-noise distortions of signed distance-fields (SDF). These SDF are used to model objects when doing rendering with the ray-marching approach. Also thanks to this noise-function, applying procedural textures becomes feasible. The whole scene is just described by a single GLSL-fragment-shader. External resources are not needed. As cool as the distortion and bending of these SDF is, it tends to cause discontinuties, which in turn lead to artefacts in the shadow-calculation and the rendering around object-silhouettes. To fight this I’ve decreased…read more

Having a full-featured 3D-suite like blender available and not knowing how to make use of its myriad of capabilities, always felt like a splinter in my eye… especially if you are very keen on all things computer-graphics and 3D. Since nothing ever happens by wishful thinking alone, you have to dive into it yourself in order to get rid of that splinter. So serving myself small helpings of written and recorded tutorials every evening, I am now able to wield some of blender’s more interesting tools at a basic level….read more