2.1 Tracking the Scene

Hello, this is Christopher Kemody and welcome to the Visual FX Compositing course. We're gonna convert this simple corridor shot into something much more impressive. And if you are doing this yourself, it may be that you've been given a piece of footage by a production company and they want you to add visual effects. Or it may be that you've been asked to create a shot like this from scratch, and if that's the case you can simply use the camera movement from your own footage like this to create something that's completely CG. We'll be doing something that's sort of halfway between that and we'll create a few CG walls and leave some of this background showing. I'll show you the other version of the clip corridor dark. This one has been darkened and made bluer. This is much more of the feel that I would want for the final shot. I've also reduced the noise in it so that it's more usable for broadcast. The problem is that because its had its noise reduced, we can't get a good track from this, and getting a good 3D track is everything. So we'll use this original for the track, and then we can drop the colored one in when we're doing the compositing work. Just be sure that you are using the most raw and original version of a clip that you have when doing the 3D track. So I'll do that now by clicking track camera. And that begins analyzing in the background. Just go to advanced and click detailed analysis to make sure that that gets all the information that you can. Of course, if this did come from a production company, they would hopefully have put tracking markers on all the walls and that would make things much, much easier. However, I'm gonna show you something that is a little more real world and that you often have to create your own shots. You're often given footage that didn't have tracking markers and you have to make the thing work even though it wasn't perfectly shot. So here we have, on the right, a blank wall, there's almost no textural detail there. So matching anything up to that is gonna require a little bit of skill. We also need to get a good track of the space in the ceiling, because that's where our main visual effect is going to be. I'll just turn the track point size up, and you can see we've got lots of tracking points on this wall, which is good. None on the wall on the right, and a few up here which may be of use to us. If you've never used the camera tracker before, the idea is that you hover around until you find one of these targets that appears to be on the correct plane. So if we look at that, that's clearly just floating in space and doesn't look right. If I select here, that circle looks as though it might be lined up with the ceiling equally over here. We can keep looking till we find something there that appears to be lined up with the plane of the wall. So I'll play right to the end of the footage and I can see there are more tracking points appearing up here for the space in the ceiling, I'm not sure that that's quite the right angle, just looking at that, it looks as though that circle might be leaning towards us a little bit. So, even though this is the area that we really want to track, we might actually get a better track somewhere back here. So, I'll test it by right-clicking and going to create solid and camera. And now, I'll just drag backwards through this, and look to see if that appears to stay in the same place. I think it does. I'm quite happy with that. I'll just undo, to get rid of it, maybe try a different tracking point. About this one. Create solid in camera. And that appears to move away from the black edge here. If you watch as we go through that's just not quite right. So I'm gonna undo that again. Keep looking for another tracking point. If the automatic selection doesn't work when you're hovering around, you can shift+click some of these points to get what you want. So I'll shift+click here, here, and here. And I actually quite like the look of that one, so I'll right click, create solid in camera and let's have a look at that. That appears to be the best so far. That being the case, I'm still going to undo, but I'm going to use those tracking points to create my ground plane. These will be very important later on when you're working in Cinema 4D. So click, shift+click, shift+click, and from here, I right-click and set ground plane and origin. Once I've done that, I can right-click and create solid in-camera. And now we need to create a solid on this wall over here as well. I could go over here and pick one of these but because those points go off screen to the left after a while, I would rather pick something from around the middle here. So then it's going to stay in sharp all the way through. So I'm looking at that. I'm just gonna right-click, create solid, and then I'll scroll backwards to see if that appears to stay in the right place. Now play through the shot. Does that look right? It does, that appears to be stuck to the wall. To test this, I can just hit S, scale that up, do the same for the one on the ceiling, and now play through again and see how that looks. Those do appear to be in the right place, lined up with the plane of the wall and the ceiling. I'll just bring up the tracking points again by clicking on the corridor layer then clicking on the 3D camera tracker. You'll notice there is nothing on the right hand wall so we can't actually create a solid for that wall. We're gonna have to simulate that later. But for now, you created a good track and put some solids in place and you're ready for the next step.