I’ve been playing around with the GIMP recently, drawing stuff, rather than editing or touching up photos. I decided to try to draw a small UFO, and the following post shows how I did it. There’s almost certainly better ways to do it, but I’m no Gimp guru!
[For those who don’t know, the GIMP is a free image processing program available for Windows, Linux and Mac, which has similar abilities to Adobe Photoshop.]
My main idea was to create the UFO as a rectangular image, and then to use the “Map Object” filter that comes with the GIMP to wrap this image around a sphere. So, first I created a rectangular image, four to five times as wide as it was high.
I wanted to have two chains of windows encircling the UFO, so the next step was to create a small layer for a single window. There are many ways to create a new layer, and I’m not going to go into details of all the methods. Please read the Gimp documentation if you want to know more.
One way is to open the Layers dialog either through the “Windows” menu or simply by hitting Ctrl + L, and using the small button at the bottom to create the new layer. I recommend right clicking the new Layer and giving it a name through the “Edit Layer Attributes…” option.
Anyway, having created a new layer, I selected a small rectangular area on it, and filled it with the foreground colour, black, then I used the “Select” menu “Grow…” option to grow it by 10 pixels all round. Here’s what I had at this stage. Note the Layers dialog on the right. I always keep the Layers dialog open as it is so useful!
OK, that’s a little hard to read, I know. The important bit is the bit in the middle, the black square surrounded by a white border, the current selection. I selected “Crop to Selection” on the Layer menu to shrink the Layer to the smallest size needed.
The next stage was to create more window layers with a window in each, so I just clicked the small copy button in the middle of the bottom of the Layers dialog about ten times, with no visible change to the image. This is because all the new layers get created right on top of one another! However, all the layers are listed in the Layers dialog on the right of the screen.
I then used the Move tool to move the new layers to different positions on the screen. I made sure that I’d spread them all out. See below.
As you can see, they are not exactly aligned and spaced, so that was my next task, using the alignment tool. I wanted this middle row to to be evenly spread along the mid line of the image, so in the alignment tool properties dialog I selected “Relative to Active layer”. Then I selected all the layers on the middle line, and finally selected the Background layer. I selected the button to align the layers on the mid line of the image (the lower middle of the six buttons in the “Align” section) then I selected the button to distribute the layers evenly across the image (the one on the right of the first row of the “Distribution” section). Now the image looked like this :
So now I needed to make the second line of windows, just about the first line. So I created a further eight windows by repeatedly copying one of the lower windows, then I spread them out slightly above the other line.
Then using the alignment tool, I selected all the windows in the new line. I changed the “Relative to” value using the drop down menu to “First Item”, then aligned the windows to the first one by using the middle button in the second row of the “Align” section. The reason I aligned the windows to the first window rather than active layer is because otherwise the windows would simply overlay the first set.
Now I needed to space out the windows, so, leaving them selected, I changed the “Relative to” value back to “Active Layer”, then used the right most button on the first row of the “Distribute” section to spread the windows evenly along the line. They now matched the first line, as shown below.
At this stage I saved the image to disk, in case of accidents. The GIMP lets you undo the steps that you have taken in editing or creating an image, but sometimes (especially if you are experimenting), it is useful be able to abandon all your fiddling and start again from a known good image. However, saving an image means that you can’t backtrack from that version of the image.
Now I needed to apply the filter, but the filter appears to only work on a single layer of an image, so I flattened the image to a single layer (using the Image menu), and applied the Map Object filter to the resulting image (Filter->Map->Map Object…). I changed the lighting to make it appear that the lighting was coming from above and to the right and I also adjusted the orientation a little so that viewpoint was slightly below the UFO, as if it was flying overhead. These are options in the filter. I clicked OK and got the following result.
And that is it. It’s a simple enough image, but good enough for my purposes, and it shows a number of simple GIMP techniques. To create the image at the top of the post I merely hid the background layer and filled the areas around the UFO with sky blue. I hope that this post will be useful to someone. Obviously there is a lot of scope to improve the image, perhaps by adding doors to the lower part, landing legs and so on, but it will do me for now.
Acknowledgement : Much of the stuff on the usage of the Alignment Tool was gleaned from this article. Many thanks to the author, Debi Dallo.
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