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Index › Programming Questions & Help › Programs › Help with perlin noise-based nebula effect
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Help with perlin noise-based nebula effect (Read 1971 times)
h4t
Help with perlin noise-based nebula effect
May 20th, 2010, 8:05pm  
I've been trying to figure out this effect for quite a long time and could really use some help. I really want to understand how to create colored nebulae or cloud effects, preferably in 3D using OpenGL. Seems to be a valuable technique to add some atmospheric character to a piece.

I have read much about Perlin noise and understand how it works, but have not figured out how to take what I've learned and create colored nebulae / clouds with it.

An extreme example of what I'm looking to do can be found in most of Flight404's work, such as http://vimeo.com/935317

Feel free to dive right into deep technical discussion, I'm up for it!
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ben_hem
Re: Help with perlin noise-based nebula effect
Reply #1 - May 20th, 2010, 9:48pm  
check out Examples / Basics / Math / Noise3D.  You won't see the 3D clouds in the sketch, but the structure is there -- it's just dragging a 2D cross-section through the 3D perlin noise "brick."
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h4t
Re: Help with perlin noise-based nebula effect
Reply #2 - May 21st, 2010, 7:35am  
Thanks, that was one of the first things I had come across.

But what I'm looking to try to make is a more localized effect. Say I draw a sphere on the stage and I'd like to surround the sphere in colorful haze of perlin noise. I'm guessing its theres some lighting and blending trickery involved, but not sure how.

Another extreme example of the specific nebula / cloud effect I'm wanting to create: http://vimeo.com/646107
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V
Re: Help with perlin noise-based nebula effect
Reply #3 - May 21st, 2010, 10:20am  
He uses textures with additive blending for the effect. Create a particle system with emitter at the sphere's center and emit particle in all direction with random velocity. The choice of the texture is very important to make something look good or bad.
Also make sure you disable depth writes/mask
Play with the particle's velocity vector and age/alpha until you reach your goal

to add more to the effect he is using lines and other particles, etc.
play with that. Also try to add particles across the sphere's surface and moving them.
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Victor Martins | www.pixelnerve.com/v
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h4t
Re: Help with perlin noise-based nebula effect
Reply #4 - May 21st, 2010, 1:56pm  
Just to be clear, are you referring to the actual atmospheric fog / haze effect that surrounds the main spheres or the gooey shells around the spheres? I am referring to the hazy, cloud that seems to exist around the main spheres.
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V
Re: Help with perlin noise-based nebula effect
Reply #5 - May 21st, 2010, 6:57pm  
i was talking about the haze effect. it is done using particles with nice texture + additive blending and what i said above.
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Victor Martins | www.pixelnerve.com/v
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