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View Full Version : Combining composited 3D shadows with real "2D" shadows without overlapping? (C4D)


SCGT
02-05-2009, 09:24 PM
I want to make some animation of a 3D composition in a real footage.


I have PFTrack to make the tracking, but I don't know how to blend the 3D lighting correctly.


First, about the shadows: As you can guess, if I'll simply make a shadow "catching" matte surface, it would get overshadowed over already "2D" shadowed areas from 3D objects.

I though that maybe by making a 3D model of the 2D objects that cast the shadow which would only recieve shadows but won't cast any, it could "catch" the shadow that comes from the composited 3D object but as it doesn't cast its own shadow, if the model was created and placed correctly it would only "cut off" the 3D shadow from the areas that shouldn't contain more shadowing.

I've tried that by using a compositing tag settings and some other methods - it doesn't seem to work, it'd simlpy disable the "matte model" shadow but even though it still receives the composited model's shadow, that shadow is still visible in the areas where it should be "cut off".

And anyway, I've also thought about the cases where it neeeds to be composited with moving objects - how can you match the 3D shadowing with an animated footage objects and shadows?

And even harder - what can you do to make a composited 3D object being shadowed by a footage animated object?



And another question in a similar area - when you want to make it with a realistic lighting while combining it with GI and all of this - how can you make the lighting correct like it really gets illuminated by the real footage objects' (and general environment) reflectiveness? Especially when, again, the objects are moving and not static?


Thanks in advance.

djart73
02-15-2009, 05:03 PM
Hello SCGT,

here in Cgtalk is a very good C4D Thread where you can post your questions that have to do with C4D
http://forums.cgsociety.org/forumdisplay.php?f=47

This thread could maybe answer some of your questions

http://forums.cgsociety.org/showthread.php?f=47&t=726510

Here is little file, that shows how to set the light and so on.
http://forums.cgsociety.org/showpost.php?p=5662966&postcount=12

Greets djart73/ before rasher73

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02-15-2009, 05:03 PM
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