This is a tutorial based on the discussion here.

I am using saulgoode's basic information about how to accomplish the spiky spiral. Many embellishments were added to the discussion and can be utilized.

I recycled some images from the discussion rather than making new ones.

I've taken the liberty of using saulgoode's informational images. I numbered them and the numbers in the tutorial refer to the numbers in the images. Some images have been changed to more closely reflect the tutorial.

1. Start with a square image. I used 600 x 600px.
   
   • Rename the layer, spikes.
   
   
   
   
   
2. Filters > Render > Clouds > Plasma (or Plasma2)
   
   • Move the Turbulence slider all the way to the right. You can click the New Seed button for different variations.
   • Click this link to see the results of making the regular Plasma results seamless.
   • Plasma2 can be set so that it is seamless. There will not be a discernible joining of edges. Slide the controls to make the plasma look similar to the one for the regular Plasma filter.
   • For discussion and links to Plasma2 sources click here
   .
   
3. Click the Crop tool .
   
   • Make sure you take in the entire width of the image and make the height somewhere between 10 and 20.
4. Image > Scale Image >
   
   • Break the chain and make the height the same as the existing width.
   
   
   
   
5. Create a new layer. Click the Blend tool and find a gradient you want to use.
   
   • Click the Shape button and scroll down and click Spiral (cw).
   • Near but not exactly on the center of the image, drag down a short distance. You will need to experiment with this. Make the spiral the size you want.
6. Filters > Distort > Polar Coordinates.
   
   • Uncheck To Polar.
7. Filters > Map > Displace
   
   • Click each button next to the X and Y displacements and choose the spikes layer in each one.
   • I made the X displacement 0 and the Y displacement 50. Vary the settings to what you like. The larger the Y setting the longer the spikiness.
   
   
   
   
8. Filters > Distorts > Polar Coordinates.
   
   • To Polar.

Nicely done O.
Looks about right Mike.

About the first ...
It is cool but there are seams, (one very visible seam divide the upper half of the circle) i wonder if would be possible avoid it.

But i fear avoid seams will require a different approach ( maybe using something as Droste or similar Mapping filter but is just a guess
i have no time to experiment now i may only point on a resource to use droste avoiding seams http://www.flickr.com/photos/joshsommer ... 405604955/ I hope the link works without flickr login if not let me know )

Mike seems your is more simple but seamless

It has a seam but I think using a tileable plasma render would fix that.

I used the plasma 2 for this one and made it seamless. This is my new t-shirt.

That is really nice Molly

and yes seems that plasma 2 solve

The tutorial has been updated so that Plasma2 is included.

Excellent!
We work so well together. =)

@ Molly: I love your tee. Very nice.

I'm still experimenting with the spikes layer. I really prefer the Plasma spikes with the Turbulence set as high as it will go. I played with making the Plasma seamless by using Filters > Map > Make seamless.

As you can see, there are no seams in the results and little difference in the results. The main goal was to make the results seamless using the regular Plasma filter and it worked.

I left the stretched layers under the finished circles to show results for the spikes layers. Don't you think it a shame to through those spiky layers away? They're so pretty.

The tutorial has been updated once again for these results.

This one I made seamless before cropping and stretching.



This one was made seamless after cropping and before stretching.

I agree. Add a couple of roach holes and some Dew stains and it would be hard to tell it from the real thing.


It should probably be noted that for the purposes of Displacement Mapping, the colors in the "spikes layer" are ignored -- only the (desaturated) lightness of the map matters. Motion blurring a layer filled with RGB Noise might also be worth experimenting with (sort of a brushed metal appearance).

thank you saul. that is an interesting idea about the RGB noise..I must give it a try....

Great idea. =)

Interesting idea, saulgoode. I like the results. Thanks!

My RGB noise settings: Correlated noise, only, checked, RG & B = 1.00.

Had to give that a try. I do like the softer spikiness with the motion blur - my settings: Length 180, Angle 90; I made the motion blur layer seamless.

The displacement map settings were made larger.

they are getting fluffier all the time O..... very nice.

this is my latest messy shirt.

I've been playing with this since it was posted. To do it this way you need G'MIC and Math Map.

I'm attaching my zipped xcf file with all of the layers. The steps are numbered like the layers in the xcf file.

1. Start with a new, square image. I used 500x500px. Name the layer, bump.
   Filters > Render > Plasma. Move the Turbulence slider all the way to the right.
   
   
2. Use the crop tool and crop to the full width and to 1 pixel high, click the cropping to get an image with a single dotted line across.
   
   
   
   
   
   
3. Image > Scale Image. Break the chain to the right of the Width & Height settings by clicking it. Make the Height = 500 and click Scale. You will have colorful stripes.
   
   
4. Filters > G'MIC > Artistic > B & W ink wash. Make the size 0.22. Your bump layer will be in contrasting B & W stripes.
   
   
5. Make a new layer and name it gradient. Select the Blend tool and choose a colorful gradient. Make the Shape = Radial and the Repeat = Sawtooth Wave. Check Adaptive supersampling. In the center or near to the center drag a short way to make a gradient with several circular rows. You can drag over the image several times until you get it like you want.
   
   
6. Filters > Distorts > Polar Coordinates. Uncheck To Polar. OK.
   
   
7. Filters > Map > Displace. Make X = 0, Y = 60, and in the two dropdowns find the bump layer (B & W stripes). Click OK.
   
   
   
   
   
8. Filters > Distorts > Polar Coordinates. Check To Polar.
   
   
9. This step fills out the square image. Filters > Generic > MathMap > Distorts > Defish. Use the default settings.
   If your image is not square, in Defish click the User Values tab and gradually increase tweak until your image is filled.

Beautiful...looks like space travel tunnel or something

I like that O, very brilliant color. Reminds me a bit of a close-up of a marigold.

Well I did it three times now step by step. mine doesn't look the same at all. I will try it again with a different gradient.

Here's my go, using full-red FG to full blue BG gradient:I think I would have gotten more of a layering effect if I had made my gradient shorter.