Finish Unwrapping

Deselect all of the cube edges and then select the last two edges as numbered in the image at the left. Select "Mesh" -> "Edges" -> "Mark Seam". If you take the imaginary card board cube mentioned above and cut the seams that have been select the cube would unwrap and lay flat. That is what we have to do now, actually unwrap the cube.

This is best done with the main part of the screen split into two parts. So do that now. On the right side of the screen select the "UV/Image Editor" screen. On the left side that contains our camera view of the cube, deselect all of the edges, then click on the "Vertex Select Mode" button or (Ctrl-tab-1). Select all of the vertices with the "A" key. From the menu select "Mesh" -> "UV Unwrap" -> "Unwrap".

This will create an outline of the flattened cube in the right screen. You can see though that the while the flattened cube fits vertically, the flattened cube does not fit horizontally. To fix this click on "Image" -> "New" and in the popup set "Width" to 1536 and "Height" to 2048. This assumes that the 6 individual pictures we will wrap the cube with are 512 pixels square. Click "OK", now go back to the left screen, make sure all vertices are selected, and click on "Mesh" -> "U/V Unwrap" -> "Unwrap". This time the flattened cube will fit the rectangle in the right screen perfectally. Your right screen should look like the image to the left. There is probably a mush easier way to do the fit but I could not get any one step process to work.

Then from the menu select "Mesh" -> "Edges" -> "Mark Seam"