In this tutorial i will show you how to use an effect called Contours.

A big thank you to Draconian who inspired me to research this technique and another thanks to saulgoode, who gave me a big revelation with his mini tutorial about how to shape the alpha channel of a gradient with the Curves Tool.

Lets begin:

The Curves Tool is under Colors → Curves.
For this technique to work, change the 'Channel' to Alpha !!!




Our first example is a radial gradient: red to transparent, stroked from center to edge of the canvas on a TRANSPARENT layer !
Now drag the curve as in the screenshot below and see how the gradient changes.
This way we can tweak the gradient to our needs.



Of course it works with a linear gradient just the same.



For more examples look at this thread:
http://www.gimpchat.com/viewtopic.php?f=8&t=5789

But it doesnt stop here.
We can give our curve a much more complex shape, and tweak the appearance of the gradient like this:



or this:



or this:



And from here we come to the Contours Effect, which is something borrowed from Photoshop Layer Styles.
In PS you have 12 Contours, and each one has a different name, which describes the effect.
These Contours can be displayed with little diagrams as in this chart and what you see is a cross chart of the final effect and at the same time, the shape of the curve.



You dont have to give the curve the exact same shape, something similar is good enough to get the same effect and you can tweak your curve and the gradient by adding more anchors and playing with them.

Alternatively you can download the Contour Curves from this thread and save them to your presets:
http://www.gimpchat.com/viewtopic.php?f ... =10#p79105

Also i recommend you to read the Gimp manual for the Curves Tool, in case you dont know how to work with the curve and anchors.
http://gimp.open-source-solution.org/ma ... urves.html

Now one way to use Contours is for texteffects.
Shaping Dropshadows, Inner and Outer Glows, the Satin-effect - everything that uses Gaussian Blurred pixels on a transparent layer.
To demonstrate i made text on a grey background and added an Outer Glow by alpha selecting the text, growing by 5 and then blurring by 20, like this.



This is an Angular S-Curve and you can also use it to make rounded text.





Also, Contours are used for surface contours in Jon Stipe's layerfx script.


Im not quite sure how the layerfx script works, probably with the Contours applied to the BumpMap, but it doesnt matter because the script does it all for you.
Here is one example:

just tried, it works exactly how i suspected

01. alpha select text
02. feather
03. fill with black
04. apply Contours
05. merge down with white layer
06. BumpMap
07. PROFIT !!!

I need try more times!
Thx Esper!

Esper , Great tutorial. I have never seen this method before. I have used the filters for the effects but never looked at what is behind the filters.

Some advanced stuff here, Esper!
Had it b-marked (and i don't do that very often)

you should a-mark it instead, K1te !

OK! Will send a feature request for that to GnuTux!

you dont post as much as you used to
busy ?

Was on vacation this week, stayed away from computers and mobile devices. Only books and the ocean beach walks.
I'm back with a bag of new ideas and recharged battery, lol.

thanks Wbool !

what seems to be the problem Akros ?

Esper, you have fantastic tutorials, they really show us the 'meat' of how things work. This is the best way I learn, by focusing on one thing at a time!

thanks 2-ton, that must be the nicest compliment i ever got here

I make these my words!


I read the entire tutorial, and got great results!
Very useful even for image editing in general, not just text.

Only in the last example could not get the same result.

"just tried, it works exactly how i suspected
01. alpha select text
02. feather
03. fill with black
04. apply Contours
05. merge down with white layer
06. BumpMap
07. PROFIT !!!"

But that's because I hindrance to translation from English and lose myself in some step.
But the essence of the tutorial have absorbed believe!

Thx for the tutorials Esper!

no not lame at all
its because i was lazy
brb with better explanation

01. type your text as usual (grey is always a good color)



02. create a new transparent layer
03. alpha select your text
what we want is to create a bumpmap, but instead of blurring our text, we will do this "backwards", so
04. Select -> Feather and use a value you would normally blur
i used 12
05. fill with black and deselect



06. apply a Contour



07. create a white layer over your base-textlayer and under your feathered-textlayer
08. merge down feathered layer, so that you get your bumpmap: a white layer with black blurred contoured text



09. turn off BumpMap layer and activate textlayer - go to Filters -> Map -> BumpMap
10. make sure the Contoured BumpMap is chosen from the dropdown menu



11. decorate some more


and then some more


xcf.-file attached

Excellent tutorial, Esper. I like how you describe what you are doing, rather than just providing a bunch of steps to follow.

One thing I would point out, though it is somewhat trivial, if you make your text white to begin with then you won't have to worry about merging it with another layer to create a bumpmap.

The Bump Map filter treats transparency in the bumpmap layer as though it is black, so if you have created a black text layer, you end up with what the Bump Map filter sees as an entirely black bumpmap -- which is why you need to merge it with a white layer.

However, if you create a white text layer then the Bump Map filter will see the text as white and the transparency as black (which is basically what you want). If you use this approach, you should perform a "Layer->Layer to Image Size" before blurring to ensure the blurring won't get chopped off; and to be exactly the same as your black text on white background approach, you should check the "Invert bumpmap" option in the Bump Map dialog.

thank you saulgoode, thats very nice of you to say !

thats good to know

i did a lengthy bumpmap experiment here:
viewtopic.php?f=12&t=6202

and it shows exactly what you said, i just completely forgot about it, minus the white bumpmap with black text bit
thats the part i memorized

In contour used "Ring"
I was doing different. But now ok.
Thx Esper!

Nice tip saugoode!
Thx!!