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Nangleator
02-26-2015, 09:59 AM
I've got an animation to do that seems easy enough, if the Graph Editor tools worked like they were supposed to.

Imagine moving an object around a precisely-curved, spiral path. Now imagine copies of that object are following the same path, but at a certain point, starting to cover the distance more slowly. Separating with time, by a precise amount. So, at the end of the path, you'd have all your clones separated by equal distances.

I've found no success with plugins like Follower. The GE ought to be able to do this.

To accomplish it, you'd grab all the keys after your precise moment in time, and stretch the keys in the GE with a time value and time origin. This would work great, except I'm getting wildly scrambled keyframes NOT centered on my time origin.

NOTE: I've turned on Fractional Frames, to allow more precision, and less jagged movement afterwards. That's not the issue.

I can do it manually, holding the mouse where I want the origin, but there's no numeric feedback, so I can't do it seven times to seven different clones and get uniform results.

What am I doing wrong?

Nangleator
02-26-2015, 01:39 PM
To illustrate my only problem, #1 is the graph editor before I use Stretch, Numeric with the time center scale at the left-most keyframe. #2 is the insane result.

bazsa73
02-26-2015, 02:09 PM
Have you tried Relativity? There is this Dr Follower function, I remember I used it, it's been a while though. I check my database if I find any example.
--edit--
here we go...
127200

Nangleator
02-26-2015, 02:16 PM
I think I tried Dr. Follower. Either I couldn't understand it, or actual X, Y, Z coordinates were getting screwed up, along with the time.

I figured out part of my problem. Times in the editor numeric panel are in seconds, not frames. It's still imprecise, and you have to manually drag things around after a "calculation" but I had a small amount of success.

bazsa73
02-26-2015, 02:29 PM
Yes, relativity is another "could have been awesome..." but I could never find a proper documentation.
but now to bed...
Cheers

Nangleator
02-26-2015, 02:36 PM
Thank you!

Nangleator
02-27-2015, 08:50 AM
Okay, I got it figured out. Relativity is the key. In the center of the dialog box is a "Special Functions" field. Add the Professor, Dr. Matcher. MATCH ties one object to another, and you can make changes to position along that path with various expressions.

I understand about 0.1% of expressions, but it was enough for my purpose.

This worked for me: MATCH(ball.lwo:ball1,t-(X(time2,t)))

Relativity is applied to the object intended to follow the main object.

ball1 is the layer of the object ball.lwo that is my main object, with the complex motion path.

time2 is a null whose X position is animated to vary how far behind in time my following object is.

Jeez, in explaining this, I'm having trouble understanding it, but through trial and error, I got it to work. Dr. Follower almost worked, but there was some variation in the path between my two objects. Seems like that's impossible; for it to be close but not right. So, out of desperation, I tried the Special Functions tab. Didn't have to enter expressions in for X, Y and Z, either.

bazsa73
02-27-2015, 10:55 AM
Okay, I got it figured out. Relativity is the key. In the center of the dialog box is a "Special Functions" field. Add the Professor, Dr. Matcher. MATCH ties one object to another, and you can make changes to position along that path with various expressions.

I understand about 0.1% of expressions, but it was enough for my purpose.

This worked for me: MATCH(ball.lwo:ball1,t-(X(time2,t)))

Relativity is applied to the object intended to follow the main object.

ball1 is the layer of the object ball.lwo that is my main object, with the complex motion path.

time2 is a null whose X position is animated to vary how far behind in time my following object is.

Jeez, in explaining this, I'm having trouble understanding it, but through trial and error, I got it to work. Dr. Follower almost worked, but there was some variation in the path between my two objects. Seems like that's impossible; for it to be close but not right. So, out of desperation, I tried the Special Functions tab. Didn't have to enter expressions in for X, Y and Z, either.

Great! There are so many gems on these forums, you just added a new one. :)

Nangleator
02-27-2015, 01:31 PM
Here's the successful result. It's in kind of a PowerPoint-looking sketch rendering style. Annotations will be added in later.

I have the option, in future edits, of changing the spacing of the balls over time. Only one ball has keyframes, so nulls control expressions that move all the rest.

jwiede
02-27-2015, 02:48 PM
To illustrate my only problem, #1 is the graph editor before I use Stretch, Numeric with the time center scale at the left-most keyframe. #2 is the insane result.

You should definitely file a bug about this issue, regardless of finding a workaround -- the GE scaling should work as expected in this case.

Nangleator
02-27-2015, 02:55 PM
jwiede, I think part of my problem is the GE uses seconds, not frames in that dialog box. But it didn't use those values exactly.