Wednesday, 31 July 2013

chromed Bumpmapping

Shrinking selection in 3px steps, then converted to a path, stroke by 1px and blurred by 2px as the bumpmap.

Chrome curves, 'anisotropic smoothing' and 'Light Glow'.

In this version i tried to get the same effect with Lighting effects, using the bumpmap, but for some reason the filter doesnt recognise much detail.
It was good for adding colour though.

The cushion effect comes from the G'MIC Relief Light filter.

BumpMapping Level II

To my surprise the 'BumpMapped Logo' tutorial got the most hits of my blog so far, which inspired me to revisit the effect yesterday.
I think there is a lot of potential in bumpmapping that is overlooked and today im going to show you how you can add some complexity to the basic technique.

The key element of bumpmapping is blurring and as all my gimp-scientist-padawans know, blur means you can shape it with an alpha-curve ! :)

01. So for our exercise, i set up a square canvas 600x600px in scientific green, with guides at 50% horizontically and vertically.

02. Create a gradient on a new tansparent layer, from white to transparent, radial shape, with adaptive supersampling ticked

03. Shape the gradient with an alpha-curve, first in a rough form and then refine.

04. Create a new layer on top of your background and below the gradient in a 50ies grey (#808080).....
turn off the gradient layer !

05. With the grey layer active, bumpmap the gradient layer and you get this "speaker" shape:

06. Next create a circular selection from the middle, save it to a channel, invert and delete from the grey layer....

07. deselect then blur the channel by 5px.

08. Activate the speaker layer and bumpmap it with the channel

Now some decoration:

01. Create a new grey layer on top of the BG.

02. Create a circular selection from the middle and make it bigger than the speaker and delete from the grey layer.

03. Create a rectangular selection from the middle and delete.

04. Repeat until you get a nice decorative shape, that you like.
I also want rounded edges, so i blur (12) and then tweak with alpha curve.

Alpha select your deco and save it to a channel for future use.

05. Duplicate decor layer, put it on top, lock alpha channel, drag white over it, unlock

06. Blur white layer (8), then turn off the eye

07. Activate grey decor layer and bumpmap

08. For more decoration, call up the selection from the saved channel and shrink (i used 26),
then fill on a new transparent layer with grey.

09. Deselect – for rounded edges repeat blurring and alpha curve

10. Duplicate, put on top, lock alpha channel, drag white, unlock and blur (12) as above for the bumpmap.

11. For a little variation we are giving the bump map a contour. Heres a reminder from a previous tutorial what contours can look like:

I used this one:

Here is a little trick, giving a bumpmap a contour and then applying the bumpmap often results in jaggy edges....
what can help is blurring the bumpmap again - 3-5px seem like good values....

then bumpmap !

12. You can repeat this forever, with texture, patterns, structures. Be creative !

For another example lets give text a contour:

Type your text.
Duplicate layer, lock alpha channel, drag white over it, unlock, then blur (i used 10), shape contour, put on top.

See how you get all ugly jaggy edges when you bump map it like it is:

But blur the contoured bumpmap again by 5px and it looks like this !

To finalize the piece i mapped a gradient on the text, played with value curves and applied anisotropic smoothing (a bit like in my Kitsch Chrome Tutorial).
On top of that G'MIC 'Light Glow'.

Added a drophadow that i displaced with the speaker bumpmap.

The blue light effect is just radial motionblur

That concludes this tutorial, hope you like it !

If you want to study what i did, here is the XCF-file:

Sunday, 21 July 2013

Chrome Curves

I already posted a tutorial about alpha-curves that are good for shaping the alpha-channel. In this tutorial its all about Value or Chrome-Curves.
The channel of the curves-tool is set to the default of 'Value' (instead of Alpha).

Chrome-Curves are a way of shaping a gradient (for example), into something that looks metallic or chromed.

For demonstration purposes i filled a text selection (almanaque 145px) with a gradient:

(40ies) Grey to White (#666666 - #ffffff)

Chrome-Curves can have all sorts of shapes, from simple to extreme.

Basically its a wavy shape that goes up and down along the diagonal line in your curves diagram or, in the more extreme cases, from bottom to the top of the curves-tool dialog-box.
Here are some examples:

Curves applied to the gradient filled text:

See how the gradient changes, the more i manipulate the curve.

Bevelled Text

For the next demonstration im adding a bevel to our text and then apply custom chrome-curves.

See how tweaking the curve, step by step, changes the chrome look:

More examples for chrome-curves shaped gradients:

Chrome-Curves on a bumpmapped layer:

Finally a different approach: bumpmapping a 50ies grey layer with a 6px blurred channel and then chrome-curves.

Tuesday, 9 July 2013

Kitsch Chrome

In this tutorial i will show you how to do some psychedelic cartoony kitsch chrome.
Its very much based on monsoonami's chrome tutorial from youtube, but coloured instead of monochromatic.

01. Start with a canvas 800x400
02. Type your text - i used the font 'Xenippa medium' 184px white, and align it

03. Turn off the text and create a new layer....
04. Alpha select your basetext and fill it on the new transparent layer with a colour that you like (i used #ffd714)        
[*** see comments at the bottom of the page]

05. Deselect, then make sure the yellow coloured textlayer is activated and call up layerfx...

06. put in the values you see in my screenshot or use values that you like
make sure to set the opacity of highlight and shadow to 100%

and check 'merge with layer' !
this step is especially crucial if you use any other layer effects script
you need to end with the text layer and the background only !!
so if you still got seperate layers for highlights and shadow, merge them down !

I advise you not to use black and white for the shading, but lighter and darker variations of your basecolour.

07. Now comes the fun part: call up the curves tool, and apply a wavy chrome curve

The curves can have all kinds of shapes, experiment until you get something good - here are some examples:

Use the colour-picker that is a part of the curves tool to find specific points you want to tweak !

08. Your result may look a bit unclean or have jagged edges.....

we can fix that with G'MIC anisotropic smoothing
(the filter is now located under 'Repair' (Version

set the 'Amplitude' to 100
'Anisotropy' to the max and 'Iterations' to 2
then play with the 'Sharpness' value until it looks good

Before you hit apply, set the 'Output Mode' on the left, to 'New layer'

09. Finally apply a Dropshadow and you're done !

Here is a pink variation for AnMal, that is based on green, lol.

And another version that uses a gradient instead of one colour and the whole spectrum of possible colour curves (RGB), instead of just 'Value'.

*** Comment:
so Akros asked why i have two textlayers, when one of them isnt used at all:

there are several reasons:

a) i like to have an unchanged backup of my basetext

b) alpha selecting the white basetext and then filling it with another colour, often results in a white border, thats why i use a new layer