Since Mentor^TBC released Spongy, an amazing 128b intro raymarching a Menger sponge, I wondered how far such effect could be size optimized in JavaScript while keeping complex camera path. The answer: 281 bytes.
The goal was to optimize for size and release the result as an intro in the demoscene spirit. That explains why although it is possible to cram a Menger Sponge raymarching in 284 bytes of HTML5 with a very scarce design, the release version fits in the 512b category and retain some of the style and complexity of the original.
Menger sponge ?
The Menger sponge is a three-dimensional extension of the Cantor set and Sierpinski carpet first described by Austrian mathematician Karl Menger in 1926.
It starts as a single cube in which the central pillar is carved out in all three axis to make 20 smaller cubes on which the process is repeated.
Source codes
511 bytes
<body bgcolor=0 text=snow onload=N=[K=R.getContext('2d')];for(t=B=127,I=K.getImageData(0,0,q=64,q);t--;$=Math.cos)N[t]=t/43&1;setInterval("t++;for(i=y=-1;y<1;y+=A)for(x=-1;x<1;x+=A=1/32,I.data[i+=4]=h+h)for(m=C=$(a=t/86),S=$(a+8),c=$(b=t/B),s=$(b+8),u=x*C+S,v=y*c-u*s,u=u*c+y*s,w=C-x*S,X=q+9*$(a+b),Y=q+9*$(b-a),Z=t,h=B;--h&&m<q;X+=u,Y+=v,Z+=w)for(m=1;N[X*m&B]+N[Y*m&B]+N[Z*m&B]<2&&m<q;m*=3);K.putImageData(I,0,0)",9)>JSpongy by p01<br><canvas id=R width=64 height=64 style=width:3in;height:3in;background:#fff>281 bytes
<canvas id=R><svg onload=setInterval("for(i=q*q,C=M(t+=R.width=q),S=M(t+8);i--;R.getContext`2d`.fillRect(i/q,i%q,1,h/q))for(x=i%q/66-1,y=i/8712-1,m=w=x*C+S,X=Y=h=q,Z=t/q;m<--h;X+=y*C+w*S,Y+=y*S-w*C,Z+=C-x*S)for(m=1;(X*m%96&32)+(Y*m%96&32)+(Z*m%96&32)<64;)m*=3",M=Math.cos,t=q=132)>Technical information
The camera travels in the fractal along a cycloid without ever touching it. The camera target rotates along the Y and Z axis.
The rendering itself is done using Canvas and ImageData by simply changing the Alpha channel of each pixel in order to gain a few bytes necessary to stay under 512b.
The Menger Sponge is raymarched at fixed steps for a maximum of 128 steps. Also the inside of the fractal is computed using the formula: (Xm%3&1)+(Ym%3&1)+(Z*m%3&1)<2 where m represents the generation of the fractal.
The intrisinc resolution of the Canvas is 64 x 64.
Karma
Of course Jspongy and Spongy are available on Pouet.net
Other recent projects
There are many experiments and projects like JSPONGY to discover other here.
FRONTFEST MOSCOW It was an honour to be invited to Fronfest Moscow 2017 with the little family to give my first workshop; implementing a Twin-stick shooter using ES6 and Canvas, and to continue my CODE🎙ART series of talks + live coding aiming to inspire new web developer artists. on November 18th, 2017
VOLTRA VOLTRA: Grinding the Universe, a gritty JavaScript demo, winner of the 1024 bytes demo competition at the Assembly 2017. on August 6th, 2017
BREATHING EARTH Another take on Nadieh Bremer mesmerizing Breathing Earth visualisation, running at 60fps on a 2D Canvas without libraries or frameworks. on June 26th, 2017
10 PRINT THEREMIN AT WEB REBELS A lighting talk about labyrinth generation and theremin instrument using the Web Audio API in 219 bytes presented at Web Rebels 2016. on June 2nd, 2016
WOLF1K The idea of this entry for the JS1K contest was to do the impossible: a 1K remake of the famous WOLF5K that rocked the final edition of the5K. It does not feature guns, evil grins and violence for in WOLF1K there is no room for guns or any form of violence. on September 10th, 2010
TILT SHIFT A very fast & simple tilt-shift effect in Canvas. on January 10th, 2009
3D TOMB II 3D TOMB II: The tomb of the 4096 mummies is a first person shooter in a fully textured environment done in less than 4KB of JavaScript. on July 1st, 2007
NEJA My first JavaScript demo, presented at the Assembly 2005 where it ranked #4 on July 30th, 2005
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