The amount of blur determines the thickness. The setting for emboss will choose a direction and height and depth. But if you want to change the darkness and lightness you could put a node in the middle of the curves dialog box and adjust the light and darkness endpoints in the curves dialog on the masked layer above. I was even able to get a kind of plastic type effect. It's kind of interesting.



By the way I didn't use blur to make that letter I filled the selection with black and then used select-border-feather and filled with white. It can give a nicer bevel effect. I did blur a bit too before and after the emboss.

heres what i got, i tried what pegleg showed, but tbh, he does it with a script.....then i had another look at jamac4k's pdf
played around a bit, deleted several tries and then it dawned me:

it goes like this

01. type your text (i used Sans Bold 430px)
02. alpha to selection and save in a channel (just in case)
03. shrink selection by 5px
04. invert
05. fill with black on a new transparent layer
06. deselect and blur by 10
07. alpha select your text again and make a layermask from selection on the filled-with-black-layer
08. duplicate black layer (with the layermask) and invert color
now you have two layers with layermasks: one black (shadow) and one white (highlight)
09. according to your lightsource, erase the parts on your layermask you dont want, by painting on it with black
if the highlight layer is on top, you only need to edit that layermask and leave the shadow layer as it is
10. set shadow layer to 'Multiply' 75% and highlight-layer to 'Screen' at 75% opacity

@Esper:
Actually, the bevel effect (and probably all other *effects), as you demonstrated, can be rebuilt if you reduce the principle to its basics: What does (*effect) mean ? How and where (*effect) transforms your image. After that, I believe it only requires you to be experienced enough in digital editing (understanding and manipulation of layers, selections, layermasks, layermodes and so on) to translate the "machine processing" to a more "human processing".

I relate on this, somehow, I remember the first times I used Gimp, I was thrilled by all the possibilities, scripts, filters I used them everywhere, everytime on every font I had, I've done many logo effects and I did them randomly, always adding more random to the already random things I came up with, putting light, shadow, texture everywhere until it looks plausible to me. And, sometimes, rolling the dices and CTRL-Z many times, the effects I got were satisfying, but there were so much randomization that I found myself unable to reproduce some of these satisfying outputs. Then I began to investigate what other people did, how they did it, it was damn frustrating because I didn't understand their process, I was unable to find their "principle".

Sorry for the *story mode*

anarkhya, im not quite sure i understand what you are saying

my impression is, you say its important to understand what you are doing, instead of using a million script effects/filters

thats what im all about
thats what all the "research" im doing is for
i want knowledge and i want the control i get with knowledge
i want to be free with my creativity and not push/program buttons in a script menu

on the other hand, scripts are easy and satisfying for a certain kind of user
they want to make something pretty
so fire up a script, change a few values and voila you´ve got something nice
and you can rightfully say: i made that

Ahh! Thats a good way to do it.

Alan

That's exactly what I meant (:

but what if all you want in this world (apart from peace, a workshop and a decent camera) is a good transparent bevel? meaning no colouring at all apart from just the shadows and highlights?

i dont understand you today, must be all the snow that fell from the sky today in germany
if you delete the red layer, you would be left with just the shadow and highlights.....
care to explain that a little bit more, please

esper: tss, snow only does good things and you should jump for joy that you have it!
i meant this: i want to make from scratch a transparent bevel. i want to use that bevel as a drawable, to make a pattern over a patterned background. bump map bevelling is an entirely different thing, it doesn't give me a transparent layer. and erisian's method doesn't either. hmm... maybe i could make a bump mapped white pattern unit and remove the white, though, why didn't i think of that one before! *runs off to try*
edit: no, of course. that won't give me the highlights, just the shadows.

AnMal one way to get a fairly good transparent bevel is to use the filter edge detect sobel. Here is an Image created using this technique



The bevel is all on a seperate layer and starts at step 16 of this tutorial

Cubism
1. Open new layer A3 set to landscape. Go Layer>Transparency>Add Alpha Channel.
2. Go Filter>Render>Clouds>Plasma set Turbulence to 7 check Randomize click OK.
3. Go Layers>Transform>Offset set Y axis to 49 Check wrap around and click OK.
4. Go Filter>Blur>Pixelise set Height and Width to 155 click OK.
5. Go Layers>Transform>Offset set Y axis to 49 Check wrap around and click OK.
6. Duplicate Layer and Go>Colours>desaturate Check Luminosity and click OK.
7. Duplicate Grey scale Layer and Base Layer Again. Reposition Layers to go Grey, Colour, Grey & Colour.
8. Change top Grey Layer Mode to Dodge and the Second Grey Layer Mode to Burn.
9. Select the top Grey Layer and Go Layers>Merge Down
10. Select the Bottom Grey Layer and Go Layers>Merge down
11. Select the Top Layer and Change Layer Mode to Grain Merge, Go Layer>Merge Down
12. Go>Colours>desaturate Check Luminosity and click OK.
13. Go>Colours>Posturize set Posturize Level to 36 then Click OK.
14. Select a desired Palette from Palettes Dialogue window.
15. Go>Colours>Map>Palette Map
16. Duplicate Layer Twice, Select Middle Layer.
17. Go>Filter>Edge Detect>Sobel check Sobel Horizontal Uncheck Sobel Vertical Check Keep sign of Result (one direction Only)
18. Select top Layer
19. Go>Filter>Edge Detect>Sobel uncheck Sobel Horizontal check Sobel Vertical Check Keep sign of Result (one direction Only)
20. Select the Top Layer and Change Layer Mode to Grain Merge, Go Layer>Merge Down
21. Go Select by Colour, Uncheck all Boxes set Threshold to 0 and Select by to Composite
22. Click on the large grey area of Image.
23. Go Edit>Clear then Go Select>None.
24. Go>Colours>desaturate Check Luminosity and click OK.
25. Turn off all other layers except top Layer. Select Top Layer, change Layer Mode to Overlay and Duplicate Layer 5*.
26. Right Click on one of the layers and select Merge Visible Layers click OK.
27. Turn off all other layers except top Layer. Select Top Layer, change Layer Mode to Overlay and Duplicate Layer 5*.
28. Right Click on one of the layers and select Merge Visible Layers click OK.
29. Go Colours Invert, Duplicate Layer.
30. Select Top Layer, Go Layers>Transform>Offset set Z Axis to 1, set Y axis to1 Check Make Transparent and click OK.
31. Select Next Layer Down, Go Layers>Transform>Offset set Z Axis to -1, set Y axis to-1 Check Make Transparent and click OK.
32. Go>Layer>Merge Down
33. Duplicate Layer, Select top Layer.
34. Go>Filters>Blur>Gaussians Blur set Height to 25 and width to 25 Click OK.
35. Turn off all other layers except top Layer. Select Top Layer, Duplicate Layer 5*.
36. Right Click on one of the layers and select Merge Visible Layers click OK and change Layer Mode to Overlay.
37. Select the Middle Layer.
38. Go>Filters>Blur>Gaussians Blur set Height to 5 and width to 5 Click OK, change Layer Mode to Overlay.

If you want to see some more examples the go here He4rty's Cubism Gallery

he4rty: that's interesting, thank you, brother! some nice stuff you have in that gallery too, i loved the ice cream.

I wasn't happy with the soft look of large bevels created with blurring and bump-mapping, so I wrote the chisel script: http://registry.gimp.org/node/24217 which creates a linear heightfield to bump with rather than the gaussian curved heightfield that a blur gives you.

I discovered later that I re-invented the same technique already used by the layer effect script

-Rob A>

thanks for the link !

am i correct this effect is achieved by filling the selection with a dimpled gradient for the bumpmap ?
i used that technique for my signature text effect



Graechan:
thanks for the fx-foundry-script !
that was very interesting, because you keep all the layermasks, so that one can guess how the script achieved the effect
it seems the fx-foundry script uses the same procedure for bevels, that i "discovered" on my own

it also seems, that technique is a simple method of doing bevels, because the layerfx-plugin bevel looks different (more advanced)

that again means im not yet there

i tried he4rty's bevel technique using the sobel filter and it gave me some nice looking results:

number 2 from left has one extra layer in the bevel and that one layer made a huge difference in effect. i had to try it on paisleys, of course and the result is amazing, those pink lines got some fantastic volume. number 4 is just the bevel layers with a patterned background under and it turned out fun, it looks a bit like a bump map or a displacement map has been used on the patterned layer. but it's still a bit of a disappointment, i want a different kind of bevel, one that clearly floats on top of the pattern.

You are quite welcome. No, I didn't like the results with the shaped gradients. Here are two examples showing how it creates artifacts:



The method my chisel script uses is to create a series of 1 px smaller (or larger) selection and filling them with changing shades of grey. This gives a bevel that follows the contours of the original selection much more accurately. It also seems to eliminate some of the stippling that gets created when using dithering in the shaped gradients to try and eliminate banding.

-Rob A>

thank you, very interesting !!

does this mean, you cant recreate this effect by hand ?

EDIT: well on a second thought, i guess you can, but it would probably be a bit tedious, right ?

For small shadows or bevels I sometimes do it manually. But for lots of bevels I usually use a script. For small precise bevels or shadows I create a single pixel width layer that is duplicated and placed manually. I then play around with the opacity for each layer to achieve the desired bevel. Quite slow but you can get very accurate results by manipulating each layer. I think that is the same as Rob's chisel script? ( I have difficulty deciphering scripts ).

Sure. The general "algorithm" is as follows (I'll make it for an inner bevel of 8 pixels based on a existing selection, as an example):

Create a new black filled layer that will be the bump map.
-Set FG Colour to Black
-Save the selection
-Jot down "1" as X
(start of loop)
-Fill the current selection with the FG
-Load the saved selection
-Shrink the selection by X pixels
-Set the FG colour to be 255*X/8 (so 32, 64, 96, 128, 192, 224, 255 each time around)
-Add 1 to X and jot it down
-If X is 8 or less, go back to the start of the loop.
(end of loop)

That creates the height field to bump map. The other options to the script are to blur that, apply a curve to it, etc. but those are all just extra enhancements that could also be done manually at this point.

Note the important thing is you need to start with the same selection and shrink it an increasing number of pixels each time. If you don't do that, curves get straightened by the selection shrinking algorithm. here is an example of that filling each time with alternating white and black (I went by 2 px to show the difference:


Thinks like this CAN be done manually, but are thankless and error-prone.

-Rob A>