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View Full Version : Compositing on MotionBlured footage

Creature
11-09-2005, 12:36 PM
I've got footage of a guy fooling around and I need to place a 3d prop in his hand (like he's holding it). I've got a good tracking and the lighting and everything is decent but how do I best composite the prop in the guys hand? It's kinda tricky because sometimes the hand is quite blured due to motion blur. I want to keep the blur on the hand and composite the prop there as seamless as possible.

Any hints?
SOE digital
11-09-2005, 01:02 PM
Can't you justy apply motion blur to the object?
Creature
11-09-2005, 01:12 PM
Of course I can. But the prop needs to be behind the hand (forgot to say that in my first post). So it's partly covered by the blured hand and I was wondering how to best setup a mask for the prop which takes the bluring of the hand into account.
jussing
11-09-2005, 03:37 PM
I'd put a feather on the mask.

- Jonas
SOE digital
11-09-2005, 10:51 PM
That'll do it.
hiphopcr
11-10-2005, 03:40 AM
What program are you doing the roto in? Using motion blur on the mask instead of feather will work better.
Creature
11-10-2005, 10:43 AM
Digital Fusion 4

Can you MotionBlur a mask? Didn't know that.
hiphopcr
11-10-2005, 05:56 PM
Ah DF... that's what I use for roto everyday.

Click on the node that has your mask(s) in it, click the "masks" tab, expand the mask settings, click the "common controls" tab (looks like a radioactive sign), check motion blur, and then mess around with the settings.

I like bumping the quality up to 6 and dropping the shutter angle down, unless you need a lot of blur I'll put it at 144 or leave it at 180. Normally I drop it down to 108 with a feather of .001.

Good luck!
beaker
11-11-2005, 10:03 AM
Using motion blur on the mask does work but I find it a little slow. Instead I use a directional blur, or if you don't have that, just blur in one axis in the direction of the motion blur. Ie.. if its going across, just motion blur more in X then in Y.

Also another option, if you have Shake or Silhouette, they allow for variable soft edges so you can control the amount of blur and in which direction it goes. It is like second edge to your rotoshape. I forget if DF has this.
hiphopcr
11-11-2005, 08:14 PM
Fusion 5 has it.
JoshKirk
11-12-2005, 05:54 AM
I just saw a fusion 5 demo and it seems that program has everything. You can actually have different amounts of points for the mask fall off than your rotoshape, which was made known to us that no other app has at this point. It really blurs the lines between a 3d app and a compositing app with the 3d geometry/lighting/particles. VERY good price for students too!
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