= Creating a Planet for Orxonox =

This tutorial will show you how to create a planet with procedurale textures for Orxonox. 

== 1st Step ==

First we have to create an actual mesh for our planet. Most often people use UV-spheres for this purpose, however unsightly texture distortions occur, especially around the poles, because of the UV unwrap. Those distortions can be prevented by using a cube and moving the vertexes so that they lie on the surface of a sphere. That way there are only very minor distortions. Confused yet? Good. I'll show you now how to all that, step by step:

||First start Blender and select the pre-created cube and press '''TAB''' to enter edit mode and choose all vertexes/edges/faces.||[[Image(cube1.png)]]||
||Next press '''CTRL + E''' and from the pop-up choose the option '''Mark seam'''.||[[Image(markseam.png)]]||
||You should end up with some like this: ||[[Image(seamsselected.png)]]||
||Next, switch to '''UV Face Select''' mode, press '''U''', select '''Unwrap''' and distribute the vertexes evenly. In order to spare you the time fiddling about with this, here's a blend file with all steps done until this point.||[[Image(faceselect.png)]]||
||You should end up with something like this in the '''UV Editor''': ||[[Image(uveditorunwrapped.png)]]||
||Baking only works on existing images. That means, you have to create an image in (e.g.) gimp with a 2:3 aspect ratio (other aspect ratios work too, but the less distortion the better). A good resolution is 1536x1024. Open the image in the '''UV Editor''' under '''File'''||[[Image(openimage.png)]]||
||You now need to distribute the vertexes evenly so the whole image is used and no space wasted.||[[Image(unwrapped.png)]]||
== 2nd Step ==

Now before we go any further with the model, we'll create the texture and bake it to an image. That way we can later change the model but keep the original UV coordinates and mapping.

||Now onto the textures. Press '''F6''' to get to the texture window. '''Add new''' adds a texture layer to your model (Make sure there exists a base material in the editor window (F9)). ||[[Image(texselect.png)]]||
||There are a few procedurale texture algorithms available but most often '''Musgrave''', '''Clouds''' and '''Noise''' work best. Here you are pretty much free to play around with the settings.||[[Image(settings.png)]]||
||After setting up your algorithms, you need to assing a colour to them. Go to '''Material buttons''' (red orb) and click on '''Texture'''. Click on the texture you want to alter and click on '''Map to'''. Here you can choose the colour which you want to be assigned to the algorithm - just click on the coloured field. Proceed doing this for all your textures. You may want to assign a different colour to the gray background texture too.||[[Image(colourselect.png)]]||
||In order to get our texture into the game, we need to "bake" it, i.e. render the texture to an image. To do this, press '''F10''' and '''Bake'''. In the bake menu, click on '''Textures''' and '''BAKE''' to bake it.||[[Image(bake.png)]]||
||You'll hopefully end up with something like this in your '''UV editor'''||[[Image(baked.png)]]||
||Save the image in the UV editor, you'll need it for the game||[[Image(saveimage.png)]]||

== 3rd Step ==
In the next step we'll increase the vertexcount of the cube and map it to a sphere.

||Press '''F9''' and '''TAB''' to get into edit mode. Click on Subdive in order to increase the vertex count, about 1538 vertexes should be enough||[[Image(subdivide.png)]]||
||Next make sure that your space cursor lies in the origin. If not, just press "SHIFT + C" to reset it.||[[Image(cursor.png)]]||
||Click on '''To Sphere''', make sure it's on 100 and press ok.||[[Image(tosphere.png)]]||
||Now we need to resize the sphere's radius to 1 so that the scaling in-game works properly. Make sure the whole sphere is selected and press '''S'''. Scale it to 1.||[[Image(resize.png)]]||

You can download a template planet blend file here (you need the template.tga too):
 * ''[http://www.orxonox.net/attachment/wiki/PlanetCreation/planettemplate.blend?format=raw planettemplate.blend]''
 * ''[http://www.orxonox.net/attachment/wiki/PlanetCreation/template.tga?format=raw template.tga]''[[BR]]
All you have to do is change the textures the way you want and bake them to a file.

== 4th Step ==
Exporting Meshes is explained properly in this wiki-article:
https://www.orxonox.net/wiki/BlenderExport