Learn about methods for altering X-Spline and Bezier shapes.
- [Instructor] So far we've dealt with relatively easy footage in terms of tracking. The city footage had lot of planar surfaces built right into the buildings, so Tracker worked really easily. Now when you move on to more complex footage, with more complex surfaces, it's good to have additional options to draw your splines. Let's talk about that. So here I'm' working with project three-one with some new footage, and I'll play that back. This shows a group of soldiers running through a field.
So, obviously a lot of organic shapes, but we can still use our PlanarTracker pretty easily. So let's see what we can do with X-splines and Beziers and see what some additional options are. I'm going to go back to the first frame, and zoom in here, and let's say I wanted to track this soldier's pocket, maybe I want to add a new patch, or and injury, or something like that, I could do that. I'm going to grab the X-spline shape, and we'll start with that. Draw a shape around this part of the pocket, right mouse button click to finish it, and there we go.
Now we talked about movin' the points around, once you have them, also the handles to soften or harden the corners. You can also delete points if you decide you have too many, just select the point by clicking on it, press the delete key on your keyboard, or, opposite of that, if you need to add additional points and you do not have to keep with a four sided shape, just go up here to point insertion tool, click that, and then click on the shape. You can add as many points as you need to.
So keep in mind that, even if you have an intricate shape, Mocha still considers that shape to representative of a planar surface. In other words, the pattern underneath is just going to be always coplanar. Whatever is making that pattern physically, like this pocket, that part is going to be in the same plane. But you're not limited to simply four points. So, for example, if I peak this at the top here, it'll help me track this dark triangle, which will probably be a nice feature that'll be easy to follow over time.
Now initially when you draw a shape, it's attached to a single layer. Now, if I go and draw additional X-spline, and you can actually have as many as you want to track different parts of the scene. But if I just use the regular X-spline tool, it's going to be put on a separate layer. It's sometimes useful, and sometimes not. I'm going to go ahead and delete that. As long as that layer is highlighted in the layers control panel, I can press the delete key and get rid of it, there we go. Now, another route is to actually add an additional shape to the same layer.
If you do that, though, both shapes are considered coplanar, on the same plane. But sometimes that comes in handy. Let's give it a try so you see how it works. I'll select that layer. Now, instead of using the X-spline tool, I'm going to add the one to the right, which is called add X-spline, and now I can draw an additional shape. Same layer, two shapes. I'm going to adjust these so they're more side by side.
Alright, so now I have two shapes, that are considered coplanar. And if I track these, each shape will maintain it's original construction, in other words, the program will try to make sure that the one on the right is rectangular, on that part of the pocket, and the one on the left has a little peak, and is on that side of the pocket. Let's give it a try. That works pretty well. Now as the soldier turns around, the one on the right maintains it shape, but it's not as accurate because of the perspective change.
However, you can see both shapes keep the same relative distance from each other, keep their original construction, and are really considered part of the same plane. So, if you need to, you can break up a single layer into multiple shapes to help make the tracking easier. And this might be suitable for more complex shapes you're trying to track. Our shapes are partially occluded. Now if you don't want that second shape, you have to select the points, you can draw a marquis over them, shift select them, so they turn red, there we go.
And then just press the delete key and those points go away, and now I'm back to my original shape. So let's try the Bezier shape next. I'm going to actually get rid of this shape, delete it, grab the Bezier tool, and talk about that. Remember when you click with the Bezier tool, you just click quickly and get a point with the default tangent orientation. Now if you click, hold the mouse button down, then drag, you can determine how long that tangent is, and where it points to.
Either way, it's up to you. If you want to close the shape, you can right mouse button click, and then of course, you can move the tangent handles wherever you want, to effect the softness or hardness of the corners, in terms of if they're round, or more linear. Of course, the points themselves. If you need to add additional points, you can do that. Grab the insert tool, as many as you want, or delete them, later on, if you want to. It doesn't matter which tool you use, I personally prefer X-spline, some people like Bezier, particularly for organic shapes, it's up to you though, whichever one works.
Now, just like the X-spline, there's also an add Bezier spline tool here, so I can add a second shape that'll be tracked in similar fashion. Then if you want to get rid of that, select those points, and delete. Now aside from that, one interesting thing to keep in mind is the X-spline and the Bezier have built in feathering, however, by default, you don't see it. There is a inner edge, and the outer edge. The outer edge is simply called edge, and the inner edge is called inner.
Now by default, when you select a point, it selects both, and they're welded together. However you can go up here, to the move inner and edge points tool, and switch to app by clicking to get to the menu, and choosing one of these other options, for example, pick edge, pick edge will pick essentially the outer edge. Now, in order to see the feather, what I can do is turn on the mat. And the mat will show that as a colored area, and that's right here, show layer mats. So now I can see that if I pull the blue edge, that's the end of the feather, again, that's called edge.
I can also go back to this, and say pick enter, which is the red line, and that's the inner edge. Now if you swap 'em, in terms of where they are in space, the feather doesn't actually work. I have to remember to go back and pick edge. But if I swap them, you see the feather's no longer working that, that the blue edge outside the red inner. And then the last option after pick edge and pick inner, is pick any, which allows you to pick any point.
So if you want to, you can have a feather now. Feather is not quite as useful for motion tracking, it's really designed for broader scoping. So we're going to talk about that in more detail when we get to that part of the program. For now, though, keep in mind that there are two edges, and they're on top of each other by default. Alright, so that's a few extra things you can do with X-splines and Beziers in terms of drawing your shapes, to help you define a more complex planar surface, to help you with more complex footage.
- Setting up the application
- Organizing projects
- Creating spline shapes
- Tracking in mocha
- Using tracking data for different tasks
- Masking occlusions
- Using offset tracking
- Rotoscoping fundamentals
- Creating complex mask shapes efficiently
- Stabilizing footage
- Correcting for lens distortion in footage
- Generating a 3D camera solve
- Working with mocha VR