The third task of our current mission is to convert our sphere into a globe by using a texture image. We will need to define the mapping of each vertex to a part of the texture image to make it fit. We will use a black and white texture, where all the land mass is black and the sea is white. The image was created based on a vector map licensed under a Creative Commons license by STUDIO7DESIGNS, which can be found at http://vector4free.com/vectors/id/75. I added Antarctica and converted it to a PNG file.
After this, we will add satellite images provided by NASA's Visible Earth project (http://visibleearth.nasa.gov/). We will also add a callback handler for keyboard events and make the textures switchable.
Let's start texturing our globe:
First we need to add an image of our globe to the sketch. Download the image from the download section at www.packtpub.com/support. The map looks like this:
Drag the image to the sketch window or add it using the Add File...