simonshack wrote:
I would say, from personal experience, that the question of perpectives is perhaps the trickiest avenue of imagery analysis. This, due to the fairly advanced state (even prior to 2001) of 3D-imaging softwares, capable of simulating a given scenery from apparently different viewing angles/vantage points. It is a tough and delicate issue - if you see what I mean.
I agree with
you here. In fact, 3D-imaging is a rather old technique, and its mathematical foundations go back a very long way indeed. But the math isn't all
that difficult. It's important to keep this in mind. There's no reason to assume
that any 3D software will produce any significant perspective errors on its own, if it is fed correctly with model and camera position data.
simonshack wrote:
It should be immediately apparent to any attentive observer that, given the considerable lateral displacement of these two alleged videographers, the DEBRIS could not have been visible to both, in such near-identical fashion.
Sorry, Simon, but I beg to differ here. The lateral displacement may not be
that "considerable" if
you take into account the distance from the towers. If
you look closely enough,
you will notice
that the debris position is not FULLY identical.
If
you like, use as an extreme example the position of two stars in the sky relative to a third star. If
you look at these stars it does not matter if
you are located in Italy or in Spain, although the lateral displacement may be "considerable".
Unless
you can prove your assumption conclusively by using geometrical equations (giving all the relevant distances), I'm not inclined to
think that these videos have a perspective issue. Also, take into account
that the relative position of WTC7 and the pyramid-like building in front of it are different in both shots. So where would
you think the "backdrop" starts?
BTW, I
think the same way about the infamous Verazzano Bridge video. Mathematically the perspective is correct. Still I fully agree
that all those videos are fakes for a couple of reasons. Just remember,
you can't beat the software or any of those guys on the math. If the model is good and the camera position is chosen correctly, the perspective will be calculated just fine.
Probably the biggest possible source of errors is the composition of the final video,
that means: if it's not fully made up of CGI but contains further green screen / actor / real life stuff.
That's where we should put our focus, and I
think we already came up with a few good examples.
On a side note, there's a free software called "Terragen Classic" which can
do simple modeling and rendering of landscapes. After playing around with it for a few minutes or hours
you can make your own perspective experiments. This will help
you understand the math. I did
that to simulate the Verrazano Bridge case, to make sure I'm not mistaken there. Please let me know if
you're interested in further information.
rusty