Help with Tread animation

Hellspawn

I'm trying to model a sort of siege tank for a project. The model needs to have at least two moving parts. The first moving part is the main cannon which swivels from side to side. I wanted to make the second moving bit, the treads on which it travels. But I'm having some difficulty figuring out how to get them to move in a tank tread sort of manner.

I used a path constraint around the wheels of the vehicle with a box and then used the snapshot tool to get the treads to form. Now I'm stuck as to how to get them moving in a tread fashion. Any one have some pointers please? Thanks!!

Mark Dygert

They are one of the most difficult things to rig up but there are a few ways I've seen it done, but they really depend on the poly count, how close and how complex of a rig you're allowed to make and what kind of things can you use.

What app?

The easiest way I've seen it done, is with animated UV's.
The most complex included a lot of collision and some amazingly complex rigging.
In the middle you have some pretty high poly treads following a path(spline) by using a path constraint and animate the % along path. But it really depends on the app you're using and the projects requirements.

jocose

I dont know if you are using maya or can use maya but there is a really good rig already set up for tank treads you can just download for free:

http://www.highend3d.com/maya/downloads/mel_scripts/modeling/misc/2285.html

Hellspawn

Vig-It's a 3Ds max project. We haven't learned about Animated UV's yet, but I'll be sure to ask my professor about it tomorrow. All i need the treads to do is move. They don't need to interact with an environment or anything yet. I'll check ouyt that tank tut when i get some time. Thanks for that.

jocose- We're not supposed to use Maya, but i'll check out the link for reference :]

tanka

I was trying to do this the other day too. The best way I've found is to use the plugin jocose just posted. (I use maya)

The only problem is I can't get the damn thing working in maya 8.5

Mark Dygert

Animated UV's are pretty easy to do: Turn on auto key, move the time slider 24-30frames, open the uvw editor move the UV's around, scrub the bar.

You'll probably need to go into the curve editor and adjust the curve to be linear otherwise it will ease in and out slowly speeding up at the beginning and slowing down toward the end. While you're in there set it to constant so you don't have to create a bunch of keys, it will loop over and over again.

Ridgid treads: Use path constraint on many thread pieces.
- Create a oval shaped spline (path)
- Create a dummy, bone or some other non-rendering object
- Path constrain the dummy to the spline: Click object > Animation menu > Constraints > Path Constraint > click path spline)
- Adjust its properties in the Motion tab (Wheel) with auto key on and the time slider moved, the % along path to move the tread around the spline.
- Copy the dummy and tread piece (hopefully instance the tread so you can work on one piece and all are effected) offset its % along path so its just in front of the other piece, do that until all the tread is filled in.
- There will be gaps as it goes around the ends, but if you designed the tread well no one but you will ever notice.

Stretchy method: Using path constraint on a large section of track
- Create a long section of track
- Path constrain it to your path oval spline
- Animate the % along path
- Its going to stretch the mesh as it rounds the corners, hopefully no one will notice but you...

kodde

Not sure if this is helpful. But I made an example to teach this to my students. I can share the Maya project with you if that would be helpful.

[ame]http://www.youtube.com/watch?v=kiPn6orWwFg[/ame]

And here is my stunning texture flat

Hellspawn

Haha So turns out I wasn't the only one with this problem in class. Luckily the professor did know how to remedy our troubles.

What we ended up doing was:
- copying a single tread however many times we needed it to round the wheels.
-Using a spline to get the shape of the oval around the wheels
-Apply a pathdeform modifier to the treads with the spline as the chosen path
-Then use the Wire parameters to link the two animations together

Vig: Thanks so much for taking the time for all those suggestions. I'll defenitly make sure to check them out for reference. It's always good to have options xD

Kodde: Awesome video. That really helped me understand the whole animated UV thing better. I'm excited to try out these other options now too xD Great texture btw. Haha!

cman2k

Sorry to dig up this month-old thread but I have to say huge thanks to Vig for the nice breakdown of his process. I was able to use a similar process to get animated tank treads into the source engine, and with only a few hiccups it worked really great.

This really was an awesome resource, I looked all over google and couldn't find what I needed but this was perfect for doing bone-driven tank tread animation for a game engine, so thanks again!