[Fafner]

I am a total, utter newbie looking to learn how to use ac3d to make some scenery objects for a game. I have been playing with the free edition for a few days, and I understand the general idea, but I am a little confused about some basics. In particular, the distinction between a Surface and an Object. The nature and extent of my confusion may be illustrated three questions.

If, for example, I create two rectangles and place them so that they do not overlap in any plane, then it seems clear that I have two Surfaces. As I expect, therefore, I can change their colour independently via Select> Surface > Colour. (1) Are they both also Objects?. It seems so, because can change colour by Select > Object > Colour

If I draw a bounding box around these two rectangles and click on Object > Select > Colour, then the colour of both will be affected. Did I make these two Surfaces into an Object even though they have no vertices in common and I did not use Object > Merge ?

I am not sure if my third question is part of the same confusion, or a separate one. I create a box. According to manual I should (I think), be able to select its vertices independently ("A Vertex is a single point in 3d space"). In fact any attempt to select one, results in two opposite vertices being selected - and the same applies in the case of a sphere, even if do Surface > Remove surface only. Why, - and why are those particular two vertices linked in this way and not some others?

I have googled for some *really* basic 3d tutorials, but so far everything I have found has been a little more advanced than I need - and has tended to be specific to some particular modeller that is not ac3d. If anyone can point me to the kind of tutorial I require I will be very grateful.

Sorry for the long post.