Rotoscoping hair

[rdarkside]

Hi..this is my first post here in vfxtalk...Im doing rotoscopy for some time now...and i want to take to the next level..I heard that rotoscoping hair can be extremely difficult...

If anyone has done it before or know about it please help me on general tips because i want to give it a try...i've been using combustion...So combustion kind-of help would be much appreciated....

Thanks in advance...

Sorry for the long text in the first post.....LOL

[faridzadeh]

tips for rotoscoping hair... use many small shapes, as opposed to fewer largers shapes.

Also... in you are in combustion, you can actually use the paintbrush and brush the alpha onto the strands for those shapes that are too small to roto.

[rdarkside]

thnx for the many roto shapes idea..but what do you mean by painting??

how to take fewer bristles of hair using the paint option...please explain

thanks.....

[Gravy]

I think it's the top operator in combusion by default.

He simply means you can paint in the alpha using the paint tool where it's too fine for rotoshapes.

You should search around here for threads on roto and paint. It sounds like your pretty unfamiliar with the basic principles so those threads would help you out quite a bit. Like an artist would or the brush tool in photoshop.

Here's a couple to get you started:
http://www.vfxtalk.com/forum/iv-roto...es-t19386.html
http://www.vfxtalk.com/forum/v-paint-t19395.html

[jeremybrown]

I'm going to be the obnoxious dissenter...

I don't think hair should be roto'd. It takes too much time and is difficult for a compositor to use effectively. 9 times out of 10, doing helmet hair style roto for hair and then tracking in strands later will work better than trying to generate a matte with all those little small strands intact.

if you can get a good key, awesome. if there's only a couple small strands, go for it. Other than that, producing roto for all those tiny small little guys is just a waste of time. your time and the compositor's time is better spent ignoring the tiny hairs at first, then putting them back in later by some other means. such as tracking in small hairs later or pulling a soft key on the hairs and putting that back on top later.

of course i have to disclaim that it all depends on the shot and situation. =)

[faridzadeh]

I'm going to be the obnoxious dissenter...

I don't think hair should be roto'd. It takes too much time and is difficult for a compositor to use effectively. 9 times out of 10, doing helmet hair style roto for hair and then tracking in strands later will work better than trying to generate a matte with all those little small strands intact.

if you can get a good key, awesome. if there's only a couple small strands, go for it. Other than that, producing roto for all those tiny small little guys is just a waste of time. your time and the compositor's time is better spent ignoring the tiny hairs at first, then putting them back in later by some other means. such as tracking in small hairs later or pulling a soft key on the hairs and putting that back on top later.
=)

In an ideal world... yes.
In the world of production, if you need to roto that hair, then you WILL roto that hair.

[beaker]

of course i have to disclaim that it all depends on the shot and situation. =)

Right because most of the shots where the roto people are doing the hair is where there isn't a green/blue screen in the first place to pull a key off of.

[arunbac]

I use to roto hair by givin a rough mask to top half of the head... Almost accurate.... then i subract the bg from the characters hair.... its bit easy for me to work on with a perfect roto

[rdarkside]

oh...subtract as in u mean key it out???

[arunbac]

well not accurately keyin out but almost yes.... have u seen the option Add Subtract Invert toolbox... well subtract it in that