#Aligning 3d w lve action
2 messages in this thread
3D Studio would be capable of such a task, but there is no way I know of that
wouldn't be at least a little tedious.
In the film world this stuff is done using "plate shots" (forgive me if you
know this already), and they don't usually involve moving cameras. If you do
use a moving camera, it is critical to keep the unpredictability of camera
movements to a minimum.
If you are in control of shooting the live footage, Noah Kennedy's suggestion
is a point in the right direction, however, the size and setup of Steadicam Sr.
<g> (Jr. is a waste of time) will not allow it to function properly in many
cars. Although it is a more expensive proposition, you may want to rent a
camera car. This is a towed trailer with special suspension, special camera
bays, and you just drive your vehicle you want to shoot right up on it.
Whenever a real smooth ride is required in film, this is what is used. You
will have rock solid car and background, and thereby will minimize your 3D
camera fiddling by a considerable amount.
Another interesting idea is to use a global positioning device attatched to the
camera. You could download (there are some available that can interface with
PC's) the info and create a 3D polyline in AutoCad or 3D Studio to use as a
camera path. I'm not sure how accurate, or at what interval the positions are
recorded, but it's an idea.
Hope this helps,
John Tissavary (La Luna cie)
Andy,
Pardon my jumping in. John Tissavary mentioned GPS systems. Here's some info
on them that might help.
Global positioning devices are typically accurate only to within 3-5 meters,
assuming you have a good cross reference point to compare with. This is for
the hand held units available so readily today. More accurate models are
available from surveying companies that give accuracy down to the centimeter,
but these Geodetic grade units are bulky, time consuming, and extremely
expensive.
The handheld units work by accepting signals from 3 satellites (that may vary,
but 3 is typical). They compare the satellite signals with an internal table
of each satellite's location (a satellite almanac) and use the 3 signals to
plot a series of points. The longer you stay in one place and collect points,
the more accurate your readings. Software finagles all these sample points to
arrive at an average location.
Limitations of the units are related mostly to terrain. If you are in heavily
forested or very mountainous terrain you may have trouble getting signals from
the 3 satellites required by the handheld units.
Hope this helps with GPS units 🙂
Dave