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Another English translated chapter from my earlier work is uploaded to ResearchGate:
Little Data – Fractal Image Compression: From a Network-Historical Miscellany to a Media-Structural Rupture
Raymarching in one Tuesday
Is there a standard algorithm to create a halftone screen from a greyscale image? How was this even done before computers?
I mean like in this image. At 50%, the raster is like a checker board, and at darker tones, it's like white circles on black.
So just drawing black circles won't get you there.
#graphics #computergraphics #imageprocessing
Doing some experiments with #RayTracing #ComputerGraphics using #Bonzomatic #GLSL #shader editor.
I define a 24-cell as the intersection of 24 half-spaces in 4D (with normals all permutations of (±1,±1,0,0)), then slice through constant 4th coordinate to get a 3D object, and simulate it as a glass-like material with reflection and refraction.
Future enhancement ideas:
- handle polarised light properly (currently I ignore polarisation, simply averaging the Fresnel reflection coefficients)
- wavelength-dependent index of refraction and absorption
- anti-aliasing (currently the edges are steppy as there is only 1 sample per pixel in a regular grid)
- improve efficiency (internal ray bounce is O(N^2) where N is the number of surfaces, could probably be O(N) with some extra maths insights)
- do 4D->3D slicing on CPU instead of every ray bounce
- add other 4D shapes
#Polarisation is something I haven't done before, so I'm curious to see how to implement it and how it changes appearance.
Wrote some more about extending the "HAKMEM 149 line algorithm" to a quad rasterizer to be able to draw billboards (sprites) up to 3D sprites, the HAKMEM approach (and forward mapping) lose a bit of interest when degrees of freedom (and projection) are added up though but it was fun to retrace the sprites history a bit.
https://www.onirom.fr/wiki/codegolf/main/#HAKMEM_149_quad_rasterizer_/_sprite_scaler_+_rotation
Cool documentary from British Horizon science program detailing the early days of #ComputerGraphics #CGI #CG #VFX #VisualEffects
1981: How COMPUTER GRAPHICS Will Change the World | Horizon | Retro Tech...
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