black space widener

[Dune]

Hey guys, please help me out. I forgot how to increase the black space in a blue node setup where altitude is divided in 1 and 0 by using a sin function. I want to thin out the positive areas by increasing the negative (black) space.
get altitude in texture---divide by constant---sinus, etc.

[FrankB]

So you would like to pull the sine function more into the negative? Then simply subtract a constant from the sine.

If you want to have more space from peak to peak, then indeed dividing x, y,or z by a constant will do that for you.
You can also combine both ways.

Frank

[Dune]

Thanks Frank. I know I have it somewhere, but can't find the best way. So this should do it?

[FrankB]

the last devide is probably not necessary. All it does is reduce the amplitude of your function.
cheers
Frank

[FrankB]

perhaps a multiplier is needed instead, depending on what you want .... remember the sine leaves you with a [-1..1] range only.

[Tangled-Universe]

You want to create a gradient or "split" the altitude in 1 and 0? (split = anything above x metres = 1, below = 0).

I like using a bias scalar to skew the colour towards black or white, as this is doing it in a non-linear fashion as long as it's not set to 0.5.

[Hetzen]

There's a few ways of doing this. Frank's way would work and is right about the divide function affecting the sin amplitude. You could use a colour adjust and shift the black level into the greys.

The Gain and Bias functions which Martin suggest only work on 0 to 1 range, and will clamp anything outside this range.

Remember the Sin/Cos etc functions work in radians, 2 x Pi x your greyscale to get one full sine cycle.

[Dune]

Thanks guys. The divider works, I tested some things on a flat plane before using it on clouds. Got it now. I wanted to make some lenticular clouds ( http://www.google.nl/search?client=opera&rls=nl&q=lenticular+clouds&oe=utf-8&channel=suggest&um=1&ie=UTF-8&hl=nl&tbm=isch&source=og&sa=N&tab=wi&ei=aJJqUKCuJsay0QX3qIDABw&biw=1890&bih=1102&sei=bZJqUKz0D8XH0QWGk4HoBw ), and now I know how.

[Dune]

I do have another question; How can you stretch a fractal from a central point (be it 0/0/0 or somewhere else) outwards?

[Hetzen]

That looks like its working.

DandelO had something a while back with voronoi.

[Dune]

That's what I thought, I'll scour the forum...

[j meyer]

Just in case ...this is the thread I remember
http://www.planetside.co.uk/forums/index.php?topic=12144.0

[dandelO]

That thread does show how to rescale a noise from a central point but I think if you just want to stretch a fractal XZ range, the easiest way would be to to localise a cloud, check 'move textures' and then position the cloud to where you want to scale around manually, that should work. Without checking 'move textures', you should just have to reposition the fractal(and probably the warp/stretcher to match) with a transform shader and stretch from there.

[Dune]

Thanks guys. It was in fact that thread I had in mind, but it's not exactly what I wanted. Maybe it's not too important anyway, just curiosity. And it wasn't about clouds, but about a way to procedurally make some sort of flow map out of the crater from some ridges stretched outward. I do have a procedural 'star', but that's too uniform. But again; I don't think it'll work as nicely as a WM flow map.