Thank you, that beautifully explained the relations. It seems so obvious now :)
The final code would be something like, camera.zoom = d/camera.focus+1; where d is the distance from the camera to the plane, for those who are interested. Thanks, Andreas On Thu, Nov 12, 2009 at 7:29 PM, Peter Kapelyan <[email protected]> wrote: > Hello! > > I found these magic formulas in some older threads here: > > z = focus*(zoom - 1) > or > scale = zoom/(1 + z/focus) > > I don't know if that will help you at all, but maybe you could figure it out > from one of those, otherwise there might be some other formulas dealing with > zoom and focus, which you'd be able to find if you search for "zoom focus" > in this group. > > Best > -Peter > > On Thu, Nov 12, 2009 at 11:13 AM, Andreas Bruse <[email protected]> wrote: >> >> Hi! >> >> I've been meaning to write a game, where one important part of the >> game mechanics would be a switch between a perspective projection and >> a parallel projection. Now, to make a nice transition between these, I >> chose not to use the ortho-lense that I've been told exists, but >> rather change the focus of the camera to a pretty large value, to get >> an as-good-as parallel projection. >> >> The problem, however, is that I want the objects at a certain plane, >> parallel to the projection plane of the camera to appear as big as >> they were before the switch of projection. Now, this is where the math >> starts kicking my ass. I realize, that as I move my focus further back >> from the projection plane, I would have to zoom out, to keep the >> points of the specific plane at the same place in the projection. I'm >> just having problems figuring out by how much. >> >> I've been drawing pretty pictures and trying to figure out the >> relation between the old projection plane and the new one, based on >> the focus, but failing miserably. >> >> So I wonder, is there anyone out there who can point me in the right >> direction to figure this out? Ideally, I would want to be able to say >> that a square, parallel to the projection plane and x pixels away from >> it, should be the same size before and after the transition (and at >> all points in between), then increase the focus gradually until it is >> large enough to look like a parallel projection, and at every point >> adjust the cameras zoom, to keep the square the same size on the >> screen. >> >> Thanks, >> Andreas > > > > -- > ___________________ > > Actionscript 3.0 Flash 3D Graphics Engine > > HTTP://AWAY3D.COM >
