spinning blades

heyvern · Post by **heyvern** » Fri Jun 19, 2009 3:06 pm

The backward motion is a "strobe" effect illusion.

Just like wheels that appear to go backwards in a movie or under a strobe light. You can only see the rotating blade or wheel on each frame. It's a single still image in a specific position. You don't see "between" the frames. There is no real motion. This illusion makes it appear to change direction. The bone isn't actually changing directions when you look at the number values.

-vern

basshole · Post by **basshole** » Fri Jun 19, 2009 3:27 pm

true. however on an exported movie i can scroll frame by frame and watch as the points on the blade appear to move backward. the suggestions you guys made seem to fix that when combined with the proper timing

basshole · Post by **basshole** » Sun Nov 22, 2009 3:14 pm

Hey, gang. I am finally ready to use this little piece of animation which I THOUGHT I had perfected. I know we have been through this exhaustively, but I realize there is a flaw in my cycled spin.

So, if I start with the angle of a bone controlling a spinning blade at 0, then at a certain key frame (21 frames later to be exact) rotate it to -360, and then cycle it back to 0, you'd think this would all work out, right? And it would continue to spin?

Yes and no. Yes it continues to spin, but it goes first one way, then at the cycle, changes directions to BACK to 0 from whence it came. I watched it do this, and I can see the bone change direction.

The only way I can figure to keep it spinning in the same direction is to increment the degrees each rotation. Example: starts at 0, goes to -360 on the next key, then -720, and so on to infinity. But how to make you this a repeating thing where you don't have to manually enter the numbers on each key? I can't see a way to do it with cycling.

slowtiger · Post by **slowtiger** » Sun Nov 22, 2009 4:32 pm

Been there, done that, palmed face ...

Maybe it comforts you to know that any ongoing rotation seems to be a problem in any animation software, and no two of those do it the same way.

What I do is this: first I do a full rotation and decide upon the speed. Let's say I decide to have a full revolution in 30 frames. Then I rebuild it in earnest, like this:

- key at #1
- do a full 360° rotation and key at #31
- make sure key #1 is set to linear
- click the bone in #30 to create a key
- erase key #31
- set key #30 to cycle (30 # relative).

That's all.
(Please adjust for any cycling tricks dependent on your AS version.)

basshole · Post by **basshole** » Sun Nov 22, 2009 11:10 pm

Thanks, yo. I'll try it.

Speaking of cycling bugs, did that ever get addressed? I'm still on 6.0. I'm afraid to upgrade to 6.1 because of a NEW bug that screw up shapes with lines that intersect or something weird like that. Which I'm sure I have.

slowtiger · Post by **slowtiger** » Mon Nov 23, 2009 12:07 am

I just installed 6.1 and will work with it next week - new client who already started in 6.1 . I will tell you which bugs I find on the way ...

Post by **Víctor Paredes** » Mon Nov 23, 2009 12:22 am

basshole wrote:Speaking of cycling bugs, did that ever get addressed? I'm still on 6.0. I'm afraid to upgrade to 6.1 because of a NEW bug that screw up shapes with lines that intersect or something weird like that. Which I'm sure I have.

If you are talking about the bug Ramón found, you can be quiet, it's very very strange to found it when working on AS, actually, it correspond to a pretty weird way to make shapes.
In 6.1 the cycling bug and many other are fixed, so don't be afraid to download it, it's far more stable than 6.0.

basshole · Post by **basshole** » Mon Nov 23, 2009 12:35 am

I have unfortunately made some very weird shapes, and have already spent much time fixing the "glitches" that sometimes appear in incorrectly made shapes. Consider me deathly afraid. Unless I can try 6.1 and then roll it back to .0 if I find problems? Without reinstalling, that is.

basshole · Post by **basshole** » Mon Nov 23, 2009 1:23 am

Ok, well, your rotation/cycling trick seems to work. So thanks.

GardenGuy · Post by **GardenGuy** » Tue Dec 08, 2009 3:35 pm

Maybe it's me but it seems like everyone is overthinking this. As a saw blade spins it is really only made up with a few positions before the blades are back in line with how they started. (Since all the blades look the same no one can tell if it's rotated all the way around to the beginning or just one part of the rotation where the blades line back up) It seems to me that it would be much more simple to do a switch layer of the blade. Use the Rotate Layer function to rotate the blade a small amount making that a new vector for the switch, rotate a little more and make a vector. Then create a switch in the animation that goes from one vector to the next. Skip the last rotation where the blades look lined up again and instead create a loop back to frame one (or whatever you have your first switch layer vector on) so that you are only repeating three or four frames. Unless there is something that has to rotate all the way around on the blade, this will give the same effect as rotating the blade in a complete circle.