Subtitles of the Movie

We are back with our spaceship. Let's widen out our top view and see that the ship is animated in a rough circle with lots of dips and bends. Let's turn off the landscape for now and zoom a bit closer. I'll scrub through the animation and you can see that we have a major problem here. The ship does not turn along its path. Now, I could keyframe the rotations of the ship like I did before and that will keep it pointing along the path, but there's a simpler way and it involves using a constraint. With the spaceship selected, I'll go to the Constraint Menu and this time I'll pick Auto Bank and the constraining object will be the ground. This mountains model. And I'll scrub again. Now our ship is following the path exactly. This is because before I added the constraint, I oriented the spaceship at the first frame of the animation correctly, pointed it along the path and then the Auto Bank Constraint maintains that orientation with respect to the mountains. So as the spaceship moves, it must keeps its initial orientation which means it has to rotate. Let's open the Constraint Editor. Auto Bank is really a wonderful tool. You can tell it to roll the object as it turns and also anticipate and have a late follow-through with these Look Ahead Fields. Very cool. But there's one more thing we need and that's pointing the camera at the spaceship. As you can see in our Camera View, we're not looking at anything yet so obviously we'll use a constraint that will automatically force the camera to track our spaceship. Now with the Camera Object selected, back to the Constraint Menu and pick Auto Look and, of course, we'll pick the spaceship. Hit Cancel and it immediately pops into view in our Camera Window. So we'll preview. Very cool. We watch the spaceship twist and turn through its complex motion path. Let's look at the animation from the top view and watch the Camera Object. It pans to follow the action, just as expected. For fun, I'll turn back on the mountains and the sky objects and we'll watch the animation again from the Camera Window. Pretty exciting shot and most of it's done with constraints and a few mouse clicks. Very little of it is hand animated with keyframes. One more project. And we have a variation of the previous animation. The spaceship flies around the same circuit but now it's carrying a missile and it's going to fire it. Let's preview. And there goes the missile. But in this shot I want the camera to shift its focus from the spaceship to the missile when the missile is fired. I can't turn the camera. The constraint forbids that. It's in control of it. So the only way to accomplish the shot that I want is to make the missile another Constraint Object. Now, before I get too far into this, let me explain a little cheat that I have in here. There are actually two missiles. We see the first missile up until the time of the firing and then it disappears and then a second missile appears and shoots away from the ship. We have two missiles because the missile needs to be parented to the ship and inherit the ship's position at the beginning of the shot. But it needs to fly away from the ship and not be affected by the ship's position. If it was the same missile throughout, then it would still be pulled by the spaceship, even if I animate it flying away. The whole flight path of the missile would be pulled and I don't want that. So the visibility of the two missiles has been keyframed on and off and off and on by setting values in the Keyframe Edit Mode. With the camera selected and the Constraint Editor open, I first need to delete the constraining object. I can't add another constraint after the first one. The constraints have to be selected at the same time so I'll add the Auto Look Constraint again and this time I'll click both the spaceship and the missile two model from the Project List. And now I have two objects in my Constraint List. The trick is to animate the weight values. So I'll jump ahead in time to Frame 186 and make sure that the spaceship's weight value is one and the missile two's weight value is zero. Then let me go to Frame 204 and I'll change the weight values to zero for the spaceship this time and one for the missile. So they switch. And I'll jump to the first frame and just make sure these values are OK. There, that's right. Now, we've animated the Camera Constraints weight value so we need to make sure you before you do this that animation has been enabled for the camera; otherwise no keyframes for the weights. Now let's preview and the camera switches its focus from following the spaceship to the fired missile. Oh, let's turn back on the background objects and watch it again. Fun, fun, fun. Constraints are amazing time savers. They may not be the answer to every animation challenge, but they are extremely useful tools.