Tutorials by BlendRoid: Making a Planet in GIMP 2

Software required: GIMP 2 Example of Finished Result:

Date of Publishing 9 October 2007

Website www.insaniac.parahosting.net

(please note that at this time the site is undergoing reconstruction from its old theme, game development, to a gallery of my

artistic works)

Copyright Information

This work is published under the Creative Commons

Attribution-No Derivative Works 3.0 United States License

Please read this short explanation

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Introduction If you’re any kind of sci-fi geek or if you just like dramatic imagery in general, you’ve probably always wanted to make one of those awesome scenes where a planet surrounded by blackness is illuminated on one side, some-times with a star peeking out from behind. A couple examples would be in the posters for Transformers and Metroid Prime 3: Corruption. This tutorial will show you how to make images like those relatively eas-ily from scratch with The GIMP. You might notice that quite a few tutorials already cover this topic in Adobe Photoshop and a few in GIMP, so why write another one? Well, the ones for Photoshop always use the nifty layer effects that GIMP doesn’t have, and the ones written for GIMP either use scripts, which take the art out of the image, or just don’t cover everything needed to make a nice planet. So, read on, and thanks for downloading my tutorial. ~ BlendRoid

Step1 - Making Your Planet’s Surface Make a new image with the dimensions 1250x1250 (or some other nicely large size). Duplicate the background layer and press Ctrl+A (select all) and Ctrl+X (cut) to make sure the new layer is empty, and then Bucket-Fill the original background layer with black. Select your empty layer and click the elliptical selection tool. Select as large an area as you can, holding down Shift to keep it perfectly circular, and centering it on the canvas as best you can (the rulers on the top and left can help out here). Do not deselect from this until I say to! Now open Filters>Render>Clouds>Solid Noise. Crank up the X/Y size to 16 and the detail to 15. Make sure “turbulent” is off. Click the New Seed but-ton until you get a nice texture without any noticeable lines going across it. Open up Colors>Levels, and drag the black output levels slider to about 80. This will lighten up the dark areas.

Our progress so far

Duplicate your cloud layer, render another Solid Noise cloud filter with the X/Y size at 8 and a new seed. Set the blending mode to Difference and set the opacity to 80 (pretty snazzy effect, huh?). Now to merge the layers into one, make sure your layer set to Difference is on top, then right-click it and select Merge Down. Now you have your basic planet surface (you also could have rendered a Difference Clouds filter on your cloud layer, but this doesn’t produce exactly the same effect). Set the blending mode to Multiply (basically, this makes the layer transparent, with lighter areas being more see-through than the dark areas; Screen is just the opposite). Make a new layer and place it under the surface layer. Make sure you still have your circle selection intact. Render yet another cloud filter with the X/Y size at 4 and a new seed. This layer is meant to give your planet some overall color variation, so adjust the color balance accordingly (Colors>Color Balance; this control is pretty self-explanatory). After you’re done, go back to your surface layer and adjust its color balance also until you have an interesting planet surface. Now merge your two colored layers.

My planet’s surface

Detailing and Rounding Your Planet Right now your planet probably looks all boring and flat, which is what we’re about to fix. First, we’ll make the surface bumpy. Duplicate your sur-face layer and open Filters>Distorts>Emboss. At this stage, you should decide where your light source is going to be, so that when the planet is shaded, the shadows on the surface match up with the shading of the sphere itself. The emboss controls take a little getting used to. First, you’ll want to set Function to Emboss. Azimuth controls the direction of the light, Elevation controls the position of the light source (think of the Sun rising in the east and setting in the west), and Depth controls how deep your ridges and depressions will be (you probably won’t want this very high). I’ve put my settings on the right. After GIMP has finished embossing, duplicate the embossed layer and make sure both of them are above your surface layer. Set the top layer’s blending mode to Multiply and the bottom one to Screen. I set my screened layer’s opacity to 15 and the multiplied one’s to 30. Now merge the three layers (when there are more than two layers to be merged, you may want to use the Image>Merge Visible Layers control, or press Ctrl+M; just make sure any layers you don’t want merged are invisible by clicking the eye next to them). You’ll notice that the screened layer bleached out your colors somewhat. To fix this I went ahead and ad-justed my color balance again. Finally, let’s make your planet round. Open Filters>Light and Shadow>Apply Lens. Set the Index of Refraction (how strongly the glass bends light) to 1.8. I’ve experimented quite a bit with the values, and this seems to be the right value for a spherical effect. Note: It is important that you emboss the surface layer before making it round. Otherwise, your planet will still appear flat.

Shading Your Planet Finally, you can deselect the circle. Select your planet layer and scale it down somewhat for two reasons: anti-aliasing and making room for atmos-pheric effects. My layer’s dimensions were about 1600x1600, so I scaled it to 1200x1200 with Interpolation set to Cubic (this keeps the most detail). There is a probably a thin ring of artifacts where the edge of your planet used to be. Just Lasso Select the ring and cut it. For the next step, it will definitely help you to have some basic artistic knowledge of shading.

My rounded planet

Instead of doing a lot of useless explaining, I’ll just show you how I did mine and you’ll probably get it. Make a new layer and make a circle selection a tad bigger than your planet. Fill the circle with black. Now deselect and open Filters>Blur>Gaussian Blur. I set the blur to 150, but it depends on the size of your image. Now position it somewhere in front of your planet so it gives the illusion of a shaded sphere, something like mine below. For some angles of light, you will need to use another method. Delete your current shading layer (or hide it) and try this out. Make a new layer, fill it with black, and hide it so you can see what you’re doing (keep it selected). Now make a circle selection (this will be where the planet is illuminated), move it somewhere logical (you can move a selection by holding down Alt and clicking and dragging), and then fill it with white. Reveal the layer and repeat your Gaussian Blur filter. Set the blending mode to Multiply. You should have something like this:

Adding an Atmosphere to Your Planet Luckily, this last step is very easy. If you have followed this tutorial cor-rectly, your layer dialogue should be similar to this: To make our atmosphere, we just have to add two layers. First, select your planet layer and click the Magic Wand. Select the area of empty space around your planet, and make a new layer. Select the new layer and fill the selected area with whatever color you want your atmosphere to be (you can adjust it later, of course). Now duplicate that layer and fill the colored area with black.

Now your layer dialogue should look like this: Try blurring the atmosphere layer with a Gaussian Blur and notice how it spreads inward around your planet. Now try blurring the mask layer and notice how the atmosphere spreads out into space (unfortunately, it also makes your atmosphere a little darker, so blur this layer cautiously). Use these two layers to control the color and thickness of your atmosphere. You can also adjust the opacity of the atmosphere layer. That’s it, you’re done! On the first page of the tutorial is my finished image. However, go to the next page for some tips on making your planet look even more spectacular!

Use a variety of methods for the surface This barren moon’s surface was made with a high detail photo of dry dirt. By the way, here I made the mistake of em-bossing after rounding. Looks kind of flat, doesn’t it? This ice world’s surface was made using a de-saturated Plasma cloud filter instead of Solid Noise. Add clouds These clouds were made with a medium-turbulence Plasma cloud filter. I cut out the darkest areas with the Magic Wand tool, made them more cloudlike with the IWarp swirl brush (Filters>Distorts>IWarp), and then used the Apply Lens filter and set them to Screen. Add a star field for a background (I don’t have a GIMP example of this yet, but that’s a topic big enough for another tutorial, so I’ll write one once I perfect it in GIMP) Be artistic and come up with your own ideas!