TO EACH HIS/HER OWN PATH

First, you have to know what a path is, before even thinking about doing one, right? A path is a curve object (Add -> Curve -> any of those) that has it's CurvePath button has pressed. (see #2)

Ok, that tells you just about nothing, so here's more: An object parented to a path will follow it through the animation, and will follow the orientation of the curve if the proper button is pressed. Wow, now that sounds useful dosen't it? Well, ok, maybe not, but wait 'till the end ok?

Now, to demonstrate the full power of path animation, we'll animate an object along the curve of our choice. Here's how to: -> Model any crappy object you can think of. The uglier, the funnier it will be. (I used a crappy UFO model made by extruding a plane and using subsurf. I'll call the object "UFO" just for simplicity) -> Add a curve and fiddle with it a bit. Just like a mesh, you can extrude (only the ends though) or subdivide it. If you want to have a 3D path, press the button labeled 3D in the Edit Buttons ("F9") (see #3).-> Make the curve become a path by pressing the CurvePath button in the Animation Buttons ("F7") (see #2)-> Now that this is done, get out of edit mode and parent the UFO to the path (ctrl-P). What? What happen? it moved away!? That's just normal, it means the path is taking effect. A dotted line should now go from the UFO's center to the Path (if it's not sitting on it directly already). That means the object has a coordinates offset from where it should be. -> Clear that offset with (alt+"o") -> Now, if you preview (alt+"a") the animation, you'll see that the UFO's position now follows the path, but it doesn't turn with it. -> To do that, select the path, and press the CurveFollow button in the Animation Butons ("F7")-> If you want the UFO to go along the path, but to start from the other end, go into Edit mode, select a CV or a Handle (depending if it's a bezier or a nurbs), press ("W") and select Switch Direction.

It should all be well now, but how do you control how much time the UFO takes to go from one end to the other? This is really easy, and there are two different ways to do it. -> First, if the path has no Curve IPO already (which it shouldn't, unless you chose Path from the Add menu), just edit the PathLen slider (see #5) in the Animation Buttons ("F7")

However, this does not give you much flexability, so a second solution would be to go into the IPO window (shift+"F6"), and under the Curve IPO tab, edit the IPO curve that is there.(see #6) Here's how it works: For Blender, a value of 0.0 would mean that the object on the path is at the begining, and a value of 100 would mean that it's at the end. Then, logicly, 0.5 means that the UFO will be in the middle of the path. Any values greater than 1.0 or lower than 0.0 will be ignored.

But, how do we know the lenght of a path, or where is the middle? That is really easy. When you enter edit mode (if your path has 3D enable), you'll see little lines along the curve. Each of these little lines designates a region of the path of the same length (length in time, not in... well, in length). Another good tool of a path is the Tilt. Just try it, enter Edit mode, select a point on your path, press ("T") and move the mouse a bit (you get something like a rotate movement). You'll notice the lines on the path titled a bit to the left or to the right. If you preview the animation now, the UFO should tilt on the side when passing near that point. Another button you will see in the Animation Buttons is the TimeOffset button. When you set it to a non-zero value, it will delay the animation of the given object that number of frame. Try it with a copy of the UFO parented to path again.

#2 Making a Curve into a Path

#3 location of the 3d button (F9)

#4 Location of the Curve Follow button (F7)

#5 PathLen Slider

#6 curve ipo button

#8 The Animation Buttons (F7)

Now, another function that you control in the Animation Buttons is DupliFrame. When you have that button enabled, a copy of the object will be created where and how it would be for each given interval of time (by default, every frame).

The DupSta and DupEnd buttons control when Blender should start/end taking a virtual copy of the object and put it in the scene. Those copy are permanent, and will be there during all the animation. By that I mean, you won't have to go to the DupSta frame to see the copies appearing. They are there from the start. The DupOff button will specify how many frames will it skip between each copy (default is 0, that means a copies of the object are calulated every frame). I used this simple technique with a path and three cylinders to create the rope you see now.

#9 - A rope made with a path and a dupliframed object

THAT'S ALL THERE IS TO SAY ABOUT THIS

That's the end! If you like it, come back next week for more! In the mean time, if you have any suggestion or comments, BIM me if I'm online or drop me a mail at theeth@yahoo.com.
I hope you've learned something, if not, you may be too good for me (or you might be [insert your favorite Blenderhead's nickname here])!

Martin
PS: OTO wears panties!
I got paid for that one (sorta), now watch carefully the 'I made this' forum, it's gonna be funny
PPS: Finally, I know I'm repeating myself, but if anybody is developing, or has developed a python script or a plugin which he thinks would be useful to everyone, just contact me, I'll try it and make a short review of it in my collumn (if it's not already released, I'll do a preview, like we did for Dynamica and BlenderMan two weeks ago).

Files:Path.blend