Bezier Masks in a Nutshell??

ilmagic wrote on 2/7/2010, 5:14 PM

Hi,
I'm battling to master the Vegas advanced compositing features, but with poor results so far. I've got a compositing software, Visionlab from FXHome, giving me good results , ease of use and all that I need, but it would be great if I could reach my compositing goals from my editing software instead of using a specific application every time I need, for instance, to apply a grade effect to a limited portion of a frame. During my Sony Vegas trialing month I noticed the program had this option in the Pan/Crop window to create keyframed masks during your ordinary editing work, and this is one of the reasons why I preferred Vegas over Premiere. Unfortunately, as I started working on my very first projects, I realised these masks are a bit tricky to manage: they're not simple vector shapes, they're Bezier curves, I'm not familiar with them. If it 's just about creating a static garbage matte, then it all works good. But when I need to create an animated mask, then adjusting the points to make them fit with the object shape turns sometimes into a living nightmare. As I move a point, an unwanted doted line appears changing the curve shape and making hard to close the path. The motion tracking is therefore shaky and unprecise. Is there a workaround to disable this curve option? I would definitely prefer to move the single points freely, like in Visionlab, instead of having these crazy handles appearing suddenly and running all around. Or else, can anybody explain in few words how these curves work?
Thank you.

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Comments

BudWzr wrote on 2/8/2010, 6:39 PM

Another option is to take a snap into CorelDraw and create a bezier or lasso cutout there, then fill it with white, invert and fill with black and save it to a PNG (don't flatten), then use that as a "cookie cutter".

You can use track motion 3D to change perspective and resize.

farss wrote on 2/8/2010, 7:28 PM

You really need to be very careful trying to fudge masks or not, it depends on what you're trying to achieve.

In the last two cases where I did some rotoscoping I got away with it because all I was trying to do was isolate a foreground element from the background so I could throw the background out of focus and desaturate it slightly. My masks didn't need to be pixel perfect so I used quite a few pixels worth of feathering. This works becasue the eye doesn't notice if an edge is blurred or the saturation drops off. I could sure see it but not the client, he thought I'd worked a miracle.

However If I'd had to pull the foreground element onto a different background I almost certainly would have had to have been pixel perfect. The eye and brain always looks at edges and get even a single pixel wobble in them and you give the game away.

Bob.

BudWzr wrote on 2/8/2010, 7:54 PM

Yeah, I have no clue what the OP is doing, so I'm just throwing out concepts. Here's a fine example of the power of Masking and 3D track motion.

What makes this video great is that stock-type footage was used as a prop to showcase the artist. To me, that's artistic.

If the film festival piece in another thread had worked the festival into the footage as if it were on everyone's mind while shmoozing, it would have been real cool.