Mapping Earth Onto A Sphere In Illustrator
This is a useful tutorial to create an earth map over a 3D sphere. Of course, be creative and you can apply this technique to other things as well. You're not just restricted to a sphere. This tutorial was written based upon Adobe Illustrator CS4 so applying this to previous versions may or may not work, you can all but try.
Finding A Platte-Carrée Map
Placing an image (texture) over a 3D object, in all mediums, requires the process known as mapping to be applied to said object. This process links a matrix of X & Y coordinates on the image to the vertices on an object. The vertices are a similar matrix of coordinates but are placed in 3D space rather than on a flat image. These coordinates are known as U & V coordinates and are used to control the shape of the object.
In order to map a texture of the Earth to a sphere in Illustrator, we require a specific type of map to reduce distortion as much as possible. This type of map is known as a Platte-Carrée Map and is used to lay flat (in a distorted manner) the cartography of the planet.
In this example we are using a dotted-effect map which can be found here:
Dotted World Map Vector Resource
After some modifying of the image, we have as a result the following map:
Blue Earth Platte-Carrée Map
Preparing The Artwork For Mapping
The next step involves preparing the artwork to be mapped. This is a simple step as all you need do is create a symbol. Open the symbols panel and drag your artwork into the thumbnail area and it will store it. Choose a symbol type (graphic or movie clip) and you're done.
Create The Sphere
Now we create our 3D sphere. To do this we require a semi-circle. To create a semi-circle, draw a perfect circle by selecting the circle tool and holding SHIFT as you drag out an ellipse, this keeps the aspect ratio at 1:1.
Once happy with the size of your circle, use the direct-selection tool (shortcut key A) and select the left-most anchor and delete it, this leaves us with a half circle.
Semi Circle created by removing left-most anchor
Now we go into the EFFECT menu and select 3D > REVOLVE. From within the 3D Revolve Options window, turn Preview on, change your Surface to wireframe, make sure your revolve angle is at 360 degrees and set your offset to 0 from the Left Edge. As a wireframe we can see how the sphere is constructed and you will get a rough idea of the UV coordinate matrix as mentioned earlier.
A wireframe sphere using the 3D Revolve tool
Apply The Map
The next step is the fun bit. Click on the Map Art button to open a new window. Choose you map symbol and if you have preview on, let your pc do its work. To set up the map so it doesn't appear distorted (this part depends on the dimensions of your artwork, different sized artwork may require different settings), within the preview panel on the Map Art window, scale your artwork so it fits from left to right, but is one grid unit below the top and one grid unit above the bottom as shown.
Adjust the artwork to fit the map
Once happy with you artwork, then use the rotating tools in the 3D Revolve Options to position your planet the way you wish.
Change the surface to No Shading to give a flat effect and hit OK.
The black bands match the stroke color of the semi circle
Lastly, select your semi-circle curve and adjust the stroke color to match the background of the Earth Map.
The final mapped planet with the semi circle stroke color matching the artwork background
You now have a completed 3D Mapped Planet.
