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import 3d model into 2d video
HI everyone
i’ve seen this effect in lots of movies where there’s a 3d model flying over a 2d background and you can see his shadows on the ground.
how can i create this effect?
do i have to use the background in the 3d software and then add the 3d model over it in the program.
or should i render the 3d model over a green screen or something and then add that in AE or anyother editing program?
anyway eater way how u add the shadows?
thanx for any help in advance -
3 Replies
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usually they use an invisible material on the ground, and that material has the ability to accept shadows or even reflections, but that’s it.
in maya the material is called “Use Background”
You can either composite it there or in AE.
You could also use the video of the 3D model over an empty BG, and then in AE duplicate the 3d footage layer and make it black (using Tint, brightness and contrast) and then add a blur to it to make it look more like a shadow. Then just lower the layer down on the Y-Axis so that it looks like it’s on the ground. You may need to play with one of the distort effects to make the shape look right.
Regardless, there’s no reson to render on a green screen – always render over an empty BG and then use an alpha channel when you output. That way it already comes in to AE with transparency, and you don;t have to deal with green halos or anything.
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Aharon Rabinowitz
aharon(AT)yahoo(DOT)com
http://www.allbetsareoff.com
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Creative Cow Master Series DVD
particleIllusion Fusion Volume 1
available @ http://www.pIllusionFusion.com -
Thanx for your reply aharon now its clear but one more question about it
i saw one time on TV that they render out a video of the model as black and white of the model and shadow or just a video of the shadow on the ground and then they have three layers :
one of the video with no shadow
one of only the shadow alpha channel
one of only the shadow with color
any idea about it?
thanx in advance -
without knowing the context of that video, it’s hard to say exactly what they are doing there. Hpwever, often, you create several render passes to get a really good composite. SOmetimes you use different transfer modes with the different passes to create a really realistic match of the 3D and BG elements.
In maya, you can shut off an object’s primary visibility, so that you can see it, but it doesn;t rernder. It does, however still create a shadow and reflection of itself, if your Use BG material (or any material in the scene) can recieve a shadow or reflection.
—————————————-
Aharon Rabinowitz
aharon(AT)yahoo(DOT)com
http://www.allbetsareoff.com
—————————————-
Creative Cow Master Series DVD
particleIllusion Fusion Volume 1
available @ http://www.pIllusionFusion.com
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