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Posted by PTravel on 10/10/06 14:40
"Rayne" <mineapollo@gmail.com> wrote in message
news:1160462218.702136.327660@i42g2000cwa.googlegroups.com...
> yep thats the kind of thing, but im going one step further...i want to
> do 3d rotations...any ideas? As simple as creating a sprite with a
> still and rotating it? Or is there some special technigque?
The only way I know of to do something like that with a full 3D rotation is
to model the primary subject in a program like Maya or 3D Studio Max. You'd
need front and back photographs that could be mapped as textures to the
model you create -- then rotate against a green background and chroma key
onto the background. What you're talking about is CGI animation, not still
manipulation. The Photoshop technique I described is relatively easy.
Creating models in Maya or 3DS Max that match still photos is not. As an
alternative, why not just shoot video of your primary subject against a
green screen and then composite it against whatever background you want?
>
>
>
> .
> PTravel wrote:
>> "Rayne" <mineapollo@gmail.com> wrote in message
>> news:1160399746.466405.211350@b28g2000cwb.googlegroups.com...
>> > Hi guys, ive been struggling trying to understand something here. Has
>> > anyone seen (hard to describe) adverts and title sequences made using
>> > stills. Pics of people or things that have been cutout and rotated
>> > about the z-axis? Channel 4 used to make a whole lot of these adverts
>> > at one point using this kind of technique...im trying to work out how
>> > to do that kind of thing, either to use after effects or Motion to
>> > create movement using stills. Help? I know its a bit tough to
>> > describe..ill try and find an example and post back..
>> >
>>
>> I think I know what you mean.
>>
>> The first step is to separate the subject from the background. This is
>> done
>> using a still image editor, like Photoshop. Start with two copies of the
>> original still. On one, use "magic lasso," "background remover" or some
>> similar tool to isolate the primary subject. Save the still in some
>> format
>> that preserves the alpha channel.
>>
>> On the other copy, use the "Healing brush" or "clone tool" to extrapolate
>> the missing background that was behind the primary subject.
>>
>> Import both stills into a video editor or effects program that can work
>> with
>> alpha channel and allows superimposition. Place the still with the
>> primary
>> subject over the still with the extrapolated background.
>>
>> Using movement tools, setup a slow zoom or pan on the still with the
>> background. Do the same thing with the primary subject still, but
>> increase
>> the speed and "distance" moved (this is an old animation technique
>> originated when cartoons were drawn on cels -- there's a name for it, but
>> I
>> can't recall at the moment).
>>
>> The resulting video makes the scene appear as if it was three
>> dimensional,
>> with the primary subject positioned in front of the background.
>>
>> Because the "hole" left in the background still when the primary subject
>> is
>> removed must be filled in, there is no way to create the entire effect in
>> a
>> video editor or effects program (at least none that I'm aware of). Also,
>> if
>> you don't have anything that works with alpha channel, you might consider
>> positioning the primary subject on a green or white background and using
>> chroma- or luminance-keying in the video editor, respectively.
>>
>>
>> >
>> > M
>> >
>
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