skybox

When rendering a sky with a fixed texture in 3D games, people often create 6 textures in a cube map first, and then render a cube around the camera. In GLSL, you can access the pixels in the textures with a normal instead of a texture coordinate, and you can easily get this normal by normalizing the fragment position relative to the camera. However, this process can be done with any shape that surrounds the camera, because when you normalize each position it will always result in a sphere. Now I'm wondering: Why is it always a cube and not a tetrahedron? Rendering a cube takes 12 triangles, a

I am trying to set the background contents of a scene to a skybox effect using about array of 6 images. I have created the array of images in the correct order, I know I need to then use + (instancetype) materialPropertyWithContents:(id)contents However I'm struggling to work out how and where exactly I use that class method to return the property containing the cube map. SCNScene's "background" property is of the SCNMaterialProperty class. So you can directly set it's contents to an array of 6 images to setup your skybox (see SCNScene.h). aScene.background.contents = @[@"Right.png", @"Left