Thorsten Wilms schrieb:
You can't have a box without VPs and VPs are useless if there is no box.
Hmm, to me a perspective is essentially _defined_ by the position/arrangement of its VPs. It seems to me that we have different understandings of the term. What do you mean by perspective then? How would you add and modify perspectives without using VPs?
Also, given my point of view I don't agree that VPs without a box are useless. Rather, they define a perspective, which you can use to draw boxes whose edges (or rather their prolongations) meet in the respective VPs, i.e. essentially to draw boxes _in the given perspective_, from a visual POV.
Note that I use the term 'perspective' in a slightly broader sense than usual here, for it also covers arrangements like the one you entitled as 'impossible' (the second picture in the 'core' section on the website). Again, it's nothing else than a configuration of VPs.
Additionaly the VPs of a perspective share a horizon.
Well, they certainly do. But I can't see why a horizon makes working with boxes cumbersome, especially since it's supposed to be only a kind of add-on to make things more convenient, but it's certainly not required for drawing boxes (and can probably be toggled to be off by default).
I still think I'm misreading you here because I don't know your precise definition of a perspective.
Regarding adding a box by dragging, I'm a bit concerned about the need for 3 drags in a row.
It's only two, actually. ;) One drag for the "front" face, and one drag to add depth.
Simply adding a box with default size would work around this (where the 'default' size should actually take the zoom level into account).
Hmm, but you don't need perspectives as separate modifiable objects to achieve that. Just add a button or a menu item or whatever to create such a box in the given configuration of VPs.
If any number of boxes can be tied to a 3-VP/horizon system, I think this clearly establishes that there are separate entities. The user can't form the right expectations if you try to cover this up.
True. We are definitely not going to cover it up. But I think it should remain to be seen how much _functionality_ for working with perspectives alone (without a box) we need to provide. Can't tell at the moment, tough.
Well, where I said 2 VPs, I actually meant 2 'finite' and one 'infinite', as I have a hard time thinking of a point if I see parallel lines ;)
Granted. I normally don't realize how much my studies of mathematics influence my thinking about these things. ;)
'have to be' is maybe a bit hard, but say you have 3 boxes, all on the same plane. 2 have parallel edges, the 3rd is rotated. The 2 share all 3 VPs, but the 3rd only has the nadir in common with them. For additional boxes, you could choose between 2 groups of VPs (or create additional VPs).
Ah, now I see what you mean. But which are the two groups? If I'm reading you correctly then you are suggesting to have one group of VPs for the two boxes with parallel edges, and a separate group for the third box, each of which you can choose for drawing new boxes. Is that right? But this is precisely the concept that I have in mind when talking about 'perspectives'. In my wording, a perspective is precisely such a group of three VPs (maybe some of them at infinity) which can be used to draw new boxes whose edges point in the directions of the VPs. So you could simply select one of the three boxes and define its 'perspective' as the default for the new box. Is this what you have in mind? Or did I get it completely wrong?
Max