You're watching the free version
of Mocha Essentials Follow along with projects and footage with the Premium download. Available at borisfx.com - [Mary] Hi, I'm Mary Poplin with Boris FX and today we're gonna talk
about PowerMesh for rotoscoping. So one of the most common uses for PowerMesh is to help
drive splines for rotoscoping. I'm gonna build upon what Ben showed you and talk about how you can use PowerMesh to drive roto splines. Now it's similar to what
Ben already showed you how to do except for, this
exercise will highlight the small changes to look out for and how this type of roto technique differs from the one we used earlier. So I'm gonna rotoscope this pigeon, which has a lot of complex movement and edges that are changing shape. We're gonna apply Mocha and launch it. Now when using PowerMesh, we do have to work in
the Classic Workspace and I'm gonna zoom into my
pigeon here a little bit. So just like when you're
dealing with any other shot inside of Mocha, you wanna
make sure that the object that you're trying to focus
on is largest in frame, least blurry and most
parallel to the camera. No problem. That's gonna be this
frame, which is frame 22. I'm gonna create a roto spline and similarly to how I've been
creating other PowerMeshes, I make sure that I stay inside the object that I'm trying to track. And we're gonna use all of this data to drive our complex roto shape. Now, if I were rotoscoping
the traditional way, I would make a shape around the head, around maybe two parts of
the neck, the wing, the body, every part of the legs and
the two different parts of the tail and wing back here and that's not necessarily
something that I want to do. So we're gonna use PowerMesh. I'm gonna turn perspective and mesh on and I'm going to use
automatic generation mode. Now I am actually going to
cut this down to about 15, use adaptive contrast
and generate the mesh. In this way I get a lot
of data to work with. I played around with a
bunch of different settings, in ten, fifteen, twenty, those are all good
settings for this pigeon. We're gonna track backwards and we're going to track forwards, and notice how PowerMesh is really capturing the
complex motion of this bird. What would normally be
handled in a whole bunch of overlapping roto shapes is now handled in one single roto shape. I feel like I'm losing
the beak a little bit. So what I'm actually going to
do is pull this roto shape out to grab the beak and track backwards, and notice how I also pulled one of the PowerMesh vertices out as well. As with any shot in Mocha,
you can always go back and change your shape
and change your track. I'm gonna call this Pigeon Roto and I'm gonna turn off my PowerMesh. On the frame that I created
my original roto shape on, I'm just gonna adjust my roto,
back to the outside edges. I'm going to use my Add
Points to Spline Tool. I'm going to relax for curves and pull tight where I want corners. So like the edges of the beak, places where the wings and tail meet, and I'm gonna create some nice adjustments to these roto pieces
down here and the wing. I wanna make sure that my roto is exactly where I want it to be, 'cause this is going to
be my reference frame. This is what I'm gonna
try to keep matching as far as the data goes for this roto. I'm gonna turn the gear
off cause we don't need to track it anymore and
I'm gonna use the track that Mocha created to try to
make an overall correction over this entire roto shape. So I'm gonna go to my last
good frame, which is here and we're gonna start
adjusting this roto shape. So just like Mocha, when
you're using just planar tracks for rotoscoping, I want you to think of using these sub planar tracks that we use inside of the PowerMesh tools as a roto assistant. It's not gonna be perfect, but what it will do is
help you cut way down on the amount of key frames
that you're creating. So now we're gonna just
do a quick correction to this roto here, and
we're gonna go to the end and see what we can get away with. You always want to add as much arc to the animation as possible, because the closer your key frames are, the more likely you are to get jitter. Now PowerMesh is really powerful but one of the places where it fails is when you have a lot of blur. So we need to correct the
shape here at the end. It also fails when lighting
changes are really severe so keep that in mind, and plan your holdout shapes accordingly. So again, we're gonna look
for that last good frame and make our corrections, and then because we got really
blurry there for a second we lost our track. So we're just gonna correct
it, where there are any jumps. And we look for the arcs of the animation. So it looks like the head is
where I have the most problems. Mostly because there's not
a lot of texture up there and that's okay, because we can just make
quick corrections to that. But I love how it's sticking
on the body and the neck and doing all of those
subtle changes for me so that I don't have to do it by hand. So again, we had a little jump there so we're gonna just correct
this roto shape one more time. Go to our jump, correct the head shape. Look for any changes. I don't see any. Here we are. Alright and really quickly
we've got a nice roto shape for our pigeon here. Let's play that. Look at all that complex
motion we're getting. We're getting, we're
capturing secondary motion. We're capturing some squash and stretch and we're capturing all of that without doing a whole ton of work. So for 93 frames of animation, I've got a single shape around my pigeon and I have 14 key frames and Mocha has done the
rest of the work for me. Now, the smaller your object is, we could probably correct this
neck to 15 key frames now. Now the less pixels you have
and the more blur that you have and the more complex
the object like fingers or this bird's feet, the more
problems you're going to have trying to track it with PowerMesh. So we talked about what frame
to start on for Warp Splines and how rotoscoping with PowerMesh is different than traditional roto. We also talked about things to look for when you're using a Warp Spline, but we're not done with this lesson. We're gonna move on to PowerMesh
for rotoscoping part two.
