Adventures

Time for another nebula update.

I have been playing with something called Strange Attractors to generate the nebula volume or cloud point list. Strange Attractors are a class of fractals but produces an unlimited amount of variations.

I got the idea from Ysaneya's journal (you should really check it out, it's really great stuff!), and with some digging I found a very nice book by Julien C. Sprott with algorithms, source samples and all. I can't say I understand all the specifics of the math involved, but it was quite interesting reading.

So, I've implemented a generator that can make 3D Strange Attractors, basically it generates a list of points that I can use to place my cloud billboards. The attractor is generated with a unique serial number so it can be recreated easily - and it don't take long to generate. I still need allot more testing before I'll call this complete.

At the moment I suffer from very poor frame rate, I think it's due to the heavy amount of alpha blending and pixel overwrites. I'm making a test using point sprites indstead to see if that can be used. Generally I have had best results with a large amount of points and very small cloud billboards - but rendering 20-30000+ quads is too much for my graphics card.

But performance tweaking comes later, first I need to be able to produce some interesting looking nebulae bodies and figure out how to do the lighting etc.

Here is a clip of how it looks so far.



Edit: Please someone, tell me how to stop YouTube from blurring and washing out the quality of me clips!

So I've fiddled some more trying to make some kind of nebula effect.
I now import my "cloud points" from a mesh and create one quad billboard for each unique vertex in the mesh.

I've had the best results while using very large amounts of smaller cloud sprites, like 3-4000, but that just chokes up my graphics card too much. I can probably tune the shader some but I think I'll go for some other way of dealing with this.

So instead I'm using less but larger cloud sprites and think I get an ok result for now.
I have also added random colors, sizes and base alpha values for the cloud sprites. Later I want to find a way of controlling those values.

Here is another clip of my nebula testing:

I've created a small video clip of my initial nebula testing.
For this test I'm using billboards.

More about this later, I just wanted to find out how to grab a video and put it on the site, so here goes....