Twist function?

[TheBlackHole]

I'm trying to make a galaxy in TG2 and I need a way to twist the cloud fractal shader. As in, something like Photoshop's Twirl filter. Can anyone help with this?

[Dune]

You'd need a warp shader or (use a power fractal as clouds, with) warp checked, and experiment with that.

[Volker Harun]

A year ago I was searching google for functions to draw spirals ... but I cannot find it anymore. Nonetheless I was able to get them working in TG2, but have not saved it
You can use a cloud fractal, multiply with the spiral function.

If you find this function, you can tell me via PM, so we can build this together.

Cheers,
Volker

[mogn]

The secret: Rotate the x-axis according to the distance, and bandpass the x-axis.

[Volker Harun]

The secret: Rotate the x-axis according to the distance, and bandpass the x-axis.

Can I be your Padawan???

[Hetzen]

The secret: Rotate the x-axis according to the distance, and bandpass the x-axis.

Hi Mogn,

I've got to say that I've never learnt about vectors, so don't really understand trigonometry too well. But how would you get the radius of your spiral to expand exponentially out, rather than having a constant distance from the previous ring.

[j meyer]

Worth a look methinks.
http://forums.planetside.co.uk/index.php?topic=3227.0

[Hetzen]

It's a thread I've visited a few times, but the spiral has the same width between rings all the way. I was wondering how you could get the width between the rings to increase the further you get away from it's centre, rather than it being fixed, like a vortex or galaxy.

[j meyer]

Sorry Hetzen,thought there was something about that in this thread,too.
Let's wait for mogn then.

[Volker Harun]

@Hetzen, You could use a square scalar between the Divide Scalar and the trig functions.

[dandelO]

Mogn to the rescue, once again! I love to see your solutions, this is great!

You could use a square scalar between the Divide Scalar and the trig functions.

And Volker, brilliant!

Slowly, oh so slowly, these little posts are all building up to become the first letter in the word 'understanding', for me!
Keep posting, you lot. Thanks!

[TheBlackHole]

Could I have a tgc of your spiral function, mogn?

[Hetzen]

Great stuff Volker and Mogn. I'm not sure how you can warp PFs with this function yet, just playing around with it now.

@Blackhole, Mogn's posted the node diagram above, you just need to put a Sqr Root funtion between the Divide and Cos/Sin nodes.

You can also stick a clamp scaler instead of the hard step nodes to get a thicker ring.

[Volker Harun]

Great stuff Volker and Mogn. I'm not sure how you can warp PFs with this function yet, just playing around with it now.

You cannot quite drive a powerfractal with it, unless you have a height sensitive conditional scalar and a smooth step afterwards ...
For the question in this thread you will not need it, as the cloud layer already has this height range built in.
So, just multiply this function's output with the cloud fractal .... everything else is done with Matt's built in stuff

You can also stick a clamp scaler instead of the hard step nodes to get a thicker ring.

Or you might want to use a smooth step scalar to get ... something smooth!?!?

,-) Salam, Volker

[Hetzen]

Just doodling. Needs loads of work, but wanted to see what anyone could do with driving this function into a couple of perlins.