WebGL for hosting GLSL

[cKleinhuis]

  @cKleinhuis: It'll be ready when it's ready... I'm putting a lot of effort into the user interface and interactivity aspects (often getting between 30-60fps interactive speeds on my 2009 iMac). It's also aimed as a creative tool for users with no programming or mathematical background (so won't have the open-ended flexibility of an app like Fragmentarium) but is more something you explore visually.

what so long ?
the rendering quality is outstanding, you have a decent quality in your productions, and i mean not only the rendering output, the interface style is very nice, too bad you took your previous version offline good work!

[willvarfar]

Subblue, what a beautiful demo video!  Do share more info!

Yes I'm having reports of black screens from people with my simple mandelbulb link; but I am hoping that webGL will settle down much quicker than I can set up a windows and mac and every other environment so I can compile native code to run on them all!

[willvarfar]

I have played around and added some 'features'.

It can draw a low-res distance map to a texture and then run again using this as input.

The display is colour coded by this info; the white pixels were discarded in an early pass, and red in were in the previous pass but not this pass.

I do the early passes with very few iterations, and crank the iterations up for the final pass.  In principle, as passes accumulate, you might get away with fewer on the final pass?

I have not found any significant speedup (nor slow-down) on my wimpy ATI mobile card, sadly.  If you save and open the file locally, you can edit it and change the parameters; easily add or change the distance map steps.

It now displays a useful frame-rate graph on the bottom of the window.  I find this more informative than a simple average number, but chrome can show a really useful FPS counter (enabled in about://flags)

I'd be most curious to know what kind of FPS this runs on your computer, what your computer spec is, and if changing the intermediate distance map texture parameters helps?

[willvarfar]

You know how it is ... I awoke this morning remembering I hadn't changed one very simple thing!

I've just fixed the epsilon on http://williame.github.com/Mandel_1 (to the near value; it could become coarser as you march, leading to better speed-ups.  (And if it grew faster than real pixels, it'd speed up more and lead to some poor-man's fuzzy depth-of-field blurring effect too.)

So now I can confirm on my rubbish mobile ATI chipset, this multi-step distance texture dramatically improves frame-rate!

Save the code https://raw.github.com/williame/Mandel_1/ed617f99df3e58c3c1ba970850e326815be336d6/index.html locally, then edit line 151 to change the number of steps and the size of the intermediate textures used.

Please report how this GPU-side "rod marching" (a.k.a. "cone marching") helps on your machine and what your spec is!

Terribly exciting

[flexiverse]

Here's a little skeleton file for anyone who finds it useful: https://gist.github.com/3139606

To run it, just right-click save-as the "raw" link and then view the file locally.

Or put it on a web server!

Feel free to use, abuse, extend, fix, share!

Put your own fractals in there, make it navigable etc.  The mandelbulb is just coloured by ray-marching steps which is hardly pretty, sorry.

As the heavy lifting of ray marching etc can be done in the GLSL shaders, we only need the tiniest of shims to host it in the browser.

Think how much space fractalforums would save if all the shared images were actually computed when displayed?

Is it possible to get the shader out so it's an external file or not as a string so it an be easily edited?