Okay, here’s the final part of the tutorial on the background image. I will explain how I created the bright star and the planet, both quite easy effects. But let’s begin with the star. This consists of three layers: the star core, the four rays of light and the halo. We’ll start with the core. Create an empty layer, pick the brush tool and select a large circle fuzzy brush. For the color, I picked a very light (almost white) blue. This is what I did next:

  1. Place a dot with the fuzzy brush;
  2. Select the dot and enlarge it 400%;
  3. Blur with a radius of 30 pixels;
  4. Place a second dot in the middle of the blurred dot.

This resulted in the following effect:

06_01.png

Next, the rays. I created another layer and selected a circular region around the star core. Next I feathered the selection, with a radius equal to the radius of the selection itself. I filled it with the star color and cut out a circular section in the middle. Finally, I blurred the layer (radius about 20 pixels) and set the transparency to 50%, giving this result:

06_02.png

That’s beginning to look like something! Finally, the rays. This effect starts out the same way as the halo. I created a blurred disc, but bigger than the halo. I then cut out rectangular sections so only the four rays remained. This should be done precisely, so use the grid and guides for this. The final result:

06_03.png

That’s it for the star. Next, the planet. I had been experimenting a bit, without much succes, when I discovered a very easy way to create realistic looking planets. Gimp has a built-in filter called sphere designer (Filters->Render->Sphere Designer). With a noise type texture, something that can pass for a planet’s surface can be created. Here’s a screenshot of the dialog box with various settings (click for large version):

06_04_small.png

This turned out to be quite impressive. And that’s it for the background image! Stay tuned for a game progress report in a few days.