A while ago I said I wasn't going to get caught up in planets. I lied. Oh well :/

Better scattering, better surface functions, better storage of textures (using cubemaps now instead of cylindrical maps for less distortion), better clouds, and finally some "real" bumpmapping via dynamic heightmap marching. Overall, pretty big improvement in visual appeal! Still needs more interesting/detailed color.

New Procedural Planets

Procedural Nebulae V

Naturally, I can't leave well enough alone!  Attempt IV was pretty cool, but it obviously lacked volume.  No surprises there: it was 2D.  Here's my first attempt at volumetric light inside of the same type of nebula as shown in the previous post.  I'm sure it will get better over time, but already you can notice a much better sense of volume, softness/cloudiness, and of light transport.  Light is correctly modeled using emissitivity and absorption as it passes through the nebula. I'd say this is a pretty good amount of nebula-related progress for 2 days!!

Procedural Volumetric Nebula
Procedural Volumetric Nebula
Procedural Volumetric Nebula

This method is about as expensive as the current LT nebulae...but it looks way I think it's safe to say this will be replacing them soon :) I am very happy with these, and I think I would quite enjoy seeing them in the background!  All the parameters - softness, brightness, feature size, absorption, wavelength-dependence of scattering, etc. are all easily-tweakable to get a lot of different styles.

Oh, and looks like we also get clouds for free! :)

Procedural Volumetric Clouds
Procedural Volumetric Clouds

Procedural Nebulae IV

Tonight, I feel like I have closed a chapter in my life.  For almost three years, I have been trying, on and off, to understand nebulae.  In particular, I've been trying to generate them procedurally.  If you look back over the log, you'll find several attempts:

2010 ~

2010 ~

2011 ~

2012 ~

2012 ~

2013 ~

Arguably, I've been getting better over the years.  As my understanding of math improves, so does my ability to craft these lovely things.  Although 2013's nebulae are significantly better than the rest (and, arguably, some of the better procedural nebulae out there on the web), let's face it, they still don't look like nebulae.  But tonight, tonight I think that I have discovered the secret of nebulae.  After three years, I finally feel that I understand these things.  And I'm proud to say that my nebulae...finally look like nebulae.


Procedural Nebulae, Three Years Later


In yet another attempt to drive the lesson of simplicity into my mind, the universe has shown me that nebulae - in my opinion, some of the most gorgeous and complex objects out there - are actually simple. The image above was produced by 31 lines of code, which is far, far less than any of my previous attempts. The code that actually defines the nebulae itself is about 20 lines. Dead simple.



I swore that I wouldn't go to bed until I made a good-looking planet in ShaderToy.  No complexity, no frills, no BS...just finding out what makes a planet look good.  LT planets look pretty bad IMO.

Thankfully, I was successful.  Not to say that this is the best-looking planet ever, or anything, but it's a definite improvement over my previous works.  AND, I finally implemented "the real deal" atmospheric scattering, instead of the cheap hacks I've been using up to this point.  It took many hours of staring at O'Neil's GPU gems article.  In the end, I was able to simplify his implementation to about 13 lines and achieve good results.  It's nice to finally have this technique under my belt :)

Real-time Planet with Atmospheric Scattering


Not sure yet if this level of quality will be achievable in-game yet...but given that it's running at 60FPS in just a pixel shader, I would say it will probably be fine :)

Beauty in Simplicity

It's difficult to grasp the fact that elegant simplicity can produce infinitely complex beauty. But this is a fact of our universe...incredible.

A one-line equation is at the heart of this beauty.


It is easy to lose oneself in such things.

(PS - My last visit to fractals looked like this. It is comforting to know that I am making progress.)

How to Write a WAV File in c++

It is surprisingly hard to find clean and simple code to do this, but it's surprisingly easy to do. Here it is, if anyone has ever wanted to write their own sound files in c++.

My code formatting in this blog is horrible, hence linking it as a separate file. Now all you do is call writeWAVData like this:

writeWAVData("mySound.wav", mySampleBuffer, mySampleBufferSize, 44100, 1);

Which would write a 44.1khz mono wav ("CD quality"). mySampleBuffer should be an array of signed shorts for 16-bit sound, floats for 32-bit, unsigned chars for 8-bit. Since the function is templatized it automatically detects the format and takes care of the relevant fields in the WAV header.

Oh, and this only works on a little-endian machine, since WAV is expected to be little...but that probably doesn't matter to anyone these're all running little endian...


Procedural Sound Synthesis

It had to happen sooner or synthesis (not composition, but actual synthesis) is one of the only realms of procedural generation that I have yet to touch...well, at least, that was true yesterday. But not anymore! :D

Yesterday I finally indulged myself in trying out audio synthesis. I read a few basic materials on the subject, but, much to my surprise, audio synthesis is incredibly simple! It seems like the audio people really enjoy making up their own fancy terminology for everything, but, honestly, it's dead simple: audio synthesis is the study of scalar functions of one variable. Period. That's literally all there is to it: a sound wave is f(t), nothing more, nothing less. Wow! That's great, because I'm already pretty darn familiar with Mr. f(t) from my work in other fields of procedural generation. Is it coincidence that it always comes back to pure math? I think not ;)

Here are a few sound effects that represent my first-ever endeavors into audio synthesis. I know, they're terrible, but they were made from scratch by someone who has only known how to synthesize audio for less than 24 hours, so maybe that makes them a little better. In the fancy audio terms, I guess you could say that I used "additive synthesis," combined with "subtractive synthesis," and even a little "frequency modulation" on top of that. But really, all I did was write some math. Sums of sines ("additive synthesis")...multiplications of those sums ("subtractive synthesis")...domain distortions ("frequency modulation"). All the usual procedural tricks. Heck, I even did the equivalent of fractal noise! Turns out it works just as well in audio. Those magical fractals :)

Well, here they are. Someday they'll get better, but certainly not in time to have procedural sound effects for LT1. Oh well. Maybe next time.

Procedural Sound 1
Procedural Sound 2
Procedural Sound 3
Procedural Sound 4
Procedural Sound 5

An Exploration of Procedural Content in Art, Music, and Reality