View Full Version : Newbie question on timing.

03-17-2003, 08:29 AM
Ok, I'm a student and have a "beginner" type question. Not quite "getting it" from the instructors explanation.

I'm doing a project where a ball comes through the air and "ricochets" off a solid box, then bounces a few times until it rolls to a stop.

I have a camera moving from the first keyframe to the end keyframe following slightly ahead of the ball and following the motion of the bouncing ball.

My problem: At the very end of the motion of the ball and camera...the ball temporarily "overtakes" the camera in speed, thus going out of the view of the camera...and then in the last few keyframes...the camera comes back in front of the ball.

I spent several hours messing with "tension and continuity and bias" as my instructor suggested...but this hasn't helped me at all to resolve the timing issue.

I want the camera to travel along just slightly in front of and to a slight angle to the ball, and keep the distance between them fairly static until the end of the animation in which the ball comes to rest with a close-up still shot from the camera.

Again, the ball, for whatever reason eventually gains speed and overtakes the camera position.

I have also fooled around with the graph editor...and honestly...I think this is the most confusing thing I've ever encountered....I select the "camera" and then try adjusting the "X and/or Z" channels, and try adjusting the vertices for these to see if I can get the camera to stay in front of the moving ball...to no avail.

Please help. I'd be happy to send what I have to anyone that may want a closer look at what I'm doing.

Thanks for all your help and wealth of knowledge.


03-17-2003, 01:36 PM
I think the graph editor is the answer here, you'll just have to spend some time with it to figure it out. I used to stay away from it until I realized that I absolutely *had* to learn how to adjust curves in the graph editor if I wanted my animations to come out right. So I spent a whole day, starting with simple animations, figuring out what everything meant. It was frustrating at first but once I figured it out, the graph editor has become my best friend, it's an enormous time saver.

If you've got a deadline and need a quick fix, you can try parenting the camera to the ball and making a few keyframes on the camera so that it isn't always the same distance from the ball; or follower might work with a negative delay. But definately learn how to use the graph editor.

03-17-2003, 01:39 PM
there's 2 ways

- keyframe the thing by hand

- create a slider and an expression driving the camera position

I'm no genious but the expression part would be like look ahead so many frames for the position of the ball to target the camera to

maybe a null object tied to that expression

if you want the ball to overtake - input a negative amount so the camera targets previous ball position

something like this is quite advanced. I would just eyeball it and keyframe the whole thing.

03-17-2003, 01:46 PM
Hi Dave,

Man, I'll keep trying....I worked with the Graph Editor for about 6 hours last night....I couldn't get it to affect the timing of my camera in a way that would work without it (adjustments to the Graph Editor) altering the position of the camera.

I was able to slow-down the entire speed of the animation by applying a 1.25 times setting in scene editor. So, that was helpful....but the timing thing has me perplexed.

I'll keep fiddling and try your suggestions...thanks.

03-17-2003, 05:06 PM
add a null and have your ball be it's parent, then track that null with the camera, see how that looks. you can move the null away from it's parent anytime to adjust where the camera is looking.

03-18-2003, 01:39 AM
I'll be honest with you: I probably don't know what I'm talking about and I probably know less about Lightwave than you. But here goes anyway...

I had a similar problem on a project where I had the camera tracking just in front of a golf ball that was moving across a putting green. When I wanted the golf ball to stop, it did so whith a kind of elastic motion where it moved past the point where I wanted it to stop and then it suddenly sprang back.

What worked for me was going into the graph editor and adjusting the points on the balls motion path from TCB to Linear - it stopped the ball from bouncing around like it was on an elastic.

Hope I'm not embarassing myself here!

03-18-2003, 03:52 AM

The very simplest thing you can do here is to clear out all the key frames from your camera and then copy/paste the ball`s motion curves into the camera`s motion curves. This of course makes the camera exactly match the ball`s movement, but puts the camera inside the ball. Huh? That`s not what you want! No, but now all you have to do is select all the keys in each of the camera`s motion curves and move them up or down in the graph editor: the motion stays the same, but the camera just gets offset to where you want it.

Now it`s just a simple matter of massaging the camera`s motion curves at the points where you want it to lag behind or accelerate infront of the ball, by moving the keys up or down in the GE a bit more.

Good luck!