I'm not 100% sure how blitz treats this. It may render that little bit quickier, but don't hold me to that.
As for the reasons for doing this: It's so you can get textures to blend with each other. If you create many surfaces, you can have each surface with it's own properties, but still be part of the same mesh.
You can change individual surfaces with the PaintSurface command.
http://www.blitzbasic.com/b3ddocs/command.php?name=PaintSurface&ref=3d_a-z
You will need to create a brush first though.
TBH, i can't think of too many instances when creating another surface would be more useful, except for certain texturing purposes (using vertexalpha on a surface, to see through to the surface below, thus creating a nice texture blend, useful for say, terrains)
Just use another entity. It's easier to rotate and move and scale.
As for the reasons for doing this: It's so you can get textures to blend with each other. If you create many surfaces, you can have each surface with it's own properties, but still be part of the same mesh.
You can change individual surfaces with the PaintSurface command.
http://www.blitzbasic.com/b3ddocs/command.php?name=PaintSurface&ref=3d_a-z
You will need to create a brush first though.
TBH, i can't think of too many instances when creating another surface would be more useful, except for certain texturing purposes (using vertexalpha on a surface, to see through to the surface below, thus creating a nice texture blend, useful for say, terrains)
Just use another entity. It's easier to rotate and move and scale.