Set fixed speed to an object?

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

Thread Tools Display Modes
  08 August 2013
Question Set fixed speed to an object?


I am sure someone here can help me with this.

Is it possible to set the speed of an object first? so for example I could set the speed of a ball to 200 units (mm in my case) per frame so that I can say I want to ball to move say 3000 units in x at a speed of 200 units per frame and then max will work out how many frames it will take.

I ask this because I am trying something more complex than a ball moving (see video). It is an animation of stairs forming. Since each consecutive plane moves up a decreased distance from the one which moved before it, and takes 40 frames to move that distance...this leads to a problem as it means each plane slows down over time, where as I want them all to move at the same speed.

I know I can work out the speed etc and do it all manually meaning I have to drop 1 frame each time, but Is there an easier way to do this? maybe wire parameters? I haven't used them much but I know they are capable of many things with the ability to add equations.

Simply though I just want to be able to set fixed speed of an object, surely that seems the easiest way to do it?

Sorry If its hard to understand what I mean, it was a little tricky to explain

Any help is appreciated

  08 August 2013
There's likely a more elegant way of doing this, but what I'd do:

1. Key each step moving the same distance over forty frames.
2. Scrub through the animation to find the spot where the stare has risen as far as you want it to rise, and put a key there.
3. Delete the key at frame forty.
  08 August 2013
First of all, look at that black key button. Close to it there's a button with a red line named "Default In/Out Tangents for new Keys". Click it and selected the red straight line.

Now, set 2 key frames, that will define how much your ball will move between those frames.
-key A - frame0 - Xaxis = 0
-key B - framme 24 - Xaxis = 500

Your object will move 500 units in 24 frames.

Then, select your object, right click and 'curve editor'.
On the left part of the object, find and select your Xposition ($YourObject > Transform > Position > X Position). On the graph view, you'll see the graph of the move.
Now, in that window, go to Edit > Controller > Out of Range Types. There are six of them. Guess you want Relative Repeat.
  08 August 2013
Excellent, thanks for the help people
  08 August 2013
Thread automatically closed

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.
CGTalk Policy/Legalities
Note that as CGTalk Members, you agree to the terms and conditions of using this website.
Thread Closed share thread

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Society of Digital Artists

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump

All times are GMT. The time now is 03:57 PM.

Powered by vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.