Go to File > New. Choose the sizing you want. I'm going with my usual sizing of 400 (width) x 125 (height). Choose whatever size you want. I'll assume you know what a blank canvas looks like so I'll spare you the image example.
This one is simple. Go to File > Open as Layer. Navigate to the render you want to use as the focal point (the render I used can be found here) and click OK. Resize and move to the centre. Mine looks like this right now:
Set the background colour to black. Use the colour picker tool to set the foreground colour from your render. In this case I pick a shade of green, as it's the most dominant colour of my render. Pick the Gradient tool. Set the style to "Radial" and Repeat to "None". Drawing from behind the render paint on the gradient. You want a good amount of colour showing; something like this:
Create a new transparent layer and call it "Galaxy".Select the brush tool and choose the "Galaxy Big" brush. Change foreground colour to white (solely for ease of seeing what you're doing). Cover the layer with these brush marks (but make sure it's not completely white). Should look something like this:
Hide the Galaxy layer. Time to do something with the background now. Duplicate your render layer several times and move each one around a bit until the whole canvas is covered (make sure you leave one render alone and in its original place). Merge all but the original render into one layer. Go to Layer > Layer to Image Size to ensure it matches the canvas size. Duplicate this layer once and hide it, as we will need it later.
Bring the original render to the front but we'll continue to work on the duplicate renders layer. Go to Filters > Map > Displace. Pick the Galaxy layer for both option and pick offsets that suit (I used 70 for both). Keep the edge behaviour as wrap and OK it.
*Sidenote* - If the Galaxy layer is not an option in the Displace dialogue then your layer boundaries are off. Back out of the dialogue and go to Layer > Layer to Image Size. Now try again.
Filters > Blur > Gaussian Blur. Blur by a suitable amount (I choose a low amount of 5 here). Now change the layer mode to something like looks good (I picked Dodge). If necessary feel free to adjust the opacity of the layer, although I didn't need to.
Hide the Galaxy layer. Create a new transparent layer called "Sparks". The more experienced GIMPers will have already guessed what this step involves. While still with the paintbrush tool select the "Sparks" brush and fill the layer with it. No leaving anything visible this time. Once that is done go to Filters > Map > Displace. Make sure the layer to be used in each dropdown box is the same sparks layer. Run at default settings (20 for x and y). Image now looks like this:
Don't worry – we're not leaving it like that. Hide the Sparks layer so that we're back at looking at the display from step 7.
Create a new transparent layer. Let's call it "Effect Base". We're still using the paintbrush tool and still with white. Change the brush to "Galaxy AP". Now comes the fun part, and where things start to get time consuming. Use this brush to mark out paths and "flares" of effects that fit around the focal. You need not mark out every path you want in one go, as they can be layered if need be. Here's my initial path (I've put a black BG so you can clearly see the path marked out but the actual layer should only have the white brushmarks):
Hide the Effect Base layer. Now remember that render copy layer we hid at the end of step 5? Yeah, we need that now so drag it to the top of the layer stack in the layers window and then make it visible. Rename it something useful like Effects 01 (note that you might want to create another duplicate of this layer in case you want to produce more effects later). Use Gaussian Blur to blur it by a low amount (I used 10). Then use Displace and use the sparks layer as the layers to use for it. Use whatever settings you want for this and OK it. I used the defaults again.
Right click the Galaxy layer in the layers window and choose "Alpha to Selection". Go back to the Effects 01 layer we were just on. Go to Select > Grow and increase the selection mask by about 5 pixels. Invert this selection and then delete from the Effects 01 layer. Select none now.
Now, we need each half of this effect on different layers. There are multiple ways to do this. My way involves duplicating the Effects 01 layer. Use the Rectangular Select tool to select one half of the layer and delete selection. Make the duplicated layer active, invert selection and delete selection. There's no visual difference from the previous step currently so no screenie required.
Select the Effects render that has shapes on the left side. Go to Filters > Map > Displace. Set both dropdowns to the Sparks layer. Leave the x and y values at default 20. OK it. Go to the other layer. Reopen the displace filter. Leave all options the same except change the x value from 20.00 to -20.00. OK it. Now you may have to move the two effects layers around a bit to get it to look good. Pick layer modes and opacity that suit them (I used Addition and left at 100 opacity).
If you want you can now choose to add more paths to the image using the same techniques from steps 9 to 13. I opted not to for mine as I was happy with the current result.
Alpha to selection one of the effects layers, then make the original render layer active. Use the eraser with a lower opacity (I used 40%) to erase from the render. Do this with each effects layer.
Make a new layer and call it Black. Change your painting colour to black and use a hard brush to just simply paint the sides black. Don't worry about being neat. Once done gaussian blur this layer by a good amount (I used 70 here). Now make a new layer called "White". Alpha to selection the black layer, switch to the white layer, invert selection and bucket fill with white.
Now just adjust the layer modes and opacity of both layers as needed to highlight the focal well. I used 100% Grain Merge for Black and 20% Value for White.
Next parts are more for colour and contrast changes, should you need them. Copy visible and paste as new layer. Set up the colours so White is foreground and Black is background. Change the gradient style to FG to BG RGB and then go do Colours > Map > Gradient Map. Set this layer to Overlay.
Do another copy visible and paste as new layer. Set it to overlay and adjust opacity as needed.
Another copy visible and paste as new layer. Go to Filters > Enhance > Sharpen. Pick something that looks good (I used 30) and OK it. Now use a soft eraser to erase around the focal point, which is all that should be left sharpened.
All you need to do now is apply the finishing touches of a border and some text. =D
Note that this tutorial may be freely redistributed anywhere providing credit is still given to the original author (me).
Previous Version of This Tutorial.
This post has been edited by Fatal Edge: 24 July 2011 - 11:57 AM