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View Full Version : animating a spool of film unraveling



mightpeebler
10-18-2005, 09:26 AM
I am more familiar with modeler. This year or animater left, and I have become responsible for that task too. I am working on a project where I am trying to make a roll of film unravel and stream out of a person's mouth. So far I have tried to modify the parchment tutorial on the newtek page to work like film. However, this has been rather problematic. I have to keep rotating the spool as it unravels to resemble film. Then the spool is still unraveling too loosely. I need it to stay tighter. Then there is the problem of making the film flow through a guide (representative of the mouth). Here I tried to use cloth dynamics to save time, but I am still a kind of a beginner so I am having a hard time getting this to work. Right now it seems like I'm going to animate each bone in the film. But it seems like lightwave 8 should have an easier solution for my problem. Does anyone have any suggestions? Is there some way to do this with dynamics, or is there some type of IK chain I could set up?

Dirk
10-18-2005, 10:54 AM
Is it possible to fake the spool? I mean, if the spool is nothing but a cylinder that's scaled down over time, it might be easier (the reel should only rotate, of course).

For the film: maybe You can animate a texture (with alpha channel) along the film?

ACLOBO
10-18-2005, 11:18 AM
I think there might be an easier solution. You just have to think aboutit in a weird way.

Consider a morph target. Create a plane that has many, many segments. stretch it out to the total length of film you will need to spew.

Shrink it down to almost noithing using the stretch tool. Make this the base, and the stretched version the morph.

As you animate the Morph in layout. see if you can add a dsiplacement texture (maybe ripple or wave?). THis should make a stream of film that ripples.

You can parent the base film object to a null so that you can place the origin where you see fit.

Another thing you might do is add a weight map to this long strip so that one end is heavy. And perhaps there is a function in the cloth dynamics to consider a weightmap for gravity?

I have never tried this before, but based on your description of what you were after, this idea just popped in my head. Hopefully it makes some sense and will at least be some food for thought. I just might have to explore this myself and see if it works.

If it does work, hire me! I need a job creating digital content instead of teaching it! lol (I AM SERIOUS DARN IT). :hey:

-Adrian

MonroePoteet
10-18-2005, 01:34 PM
Might also check out this thread and the sample scene in the last post:

http://vbulletin.newtek.com/showthread.php?t=41171

mTp

mightpeebler
10-18-2005, 07:43 PM
Might also check out this thread and the sample scene in the last post:

http://vbulletin.newtek.com/showthread.php?t=41171

mTp
So, if I do it this way, I would need to start with the film already unraveled and have it follow a motion path using bones? Also, I looked at the video tutorial, and your modeler, and scene files-why do you have one really huge bone leading to your motion path?

SplineGod
10-19-2005, 01:11 AM
I would do the roll of film and the stream of film and two separate things.
Make the roll of film shrink in size to simulate unrolling. Make the stream of film come down from behind the roll so you dont see that its not actually connected.
You can stream the film by morphing along a bone chain, using a free plugin like shift spline transform or better yet, the free trailer plugin from DStorm. The idea is that the only thing that matters is the final animation regardless if you make it behave exactly like it would in real life. :)

mightpeebler
10-19-2005, 10:01 AM
I would do the roll of film and the stream of film and two separate things.
Make the roll of film shrink in size to simulate unrolling. Make the stream of film come down from behind the roll so you dont see that its not actually connected.
You can stream the film by morphing along a bone chain, using a free plugin like shift spline transform or better yet, the free trailer plugin from DStorm. The idea is that the only thing that matters is the final animation regardless if you make it behave exactly like it would in real life. :)
Thanks Splinegod,

USing two objects made the process alot easier. I also found that using bones as a motion path really helps the streaming film.

MonroePoteet
10-19-2005, 10:10 AM
So, if I do it this way, I would need to start with the film already unraveled and have it follow a motion path using bones? Also, I looked at the video tutorial, and your modeler, and scene files-why do you have one really huge bone leading to your motion path?

Sounds like you got it working, but to answer your questions: Yes, the film is unraveled at the beginning, and uses a bone path to coil up, but then you have the keyframes in Morph Mixer reversed to make it uncoil. The huge bone is to make the hose go straight after it "leaves" the spool. I could have used a bunch of little bones in a straight line, but opted to use the huge bone instead.

I used single-piece hose and coiled it using the bone chain since it's obvious what's on the spool and what's not. With a scene where separate objects can be used, it definitely simplifies the bone path.

mTp

mightpeebler
11-28-2005, 09:40 AM
So the animation for this project is pretty much done, but now I'm running into a problem with texturing. Since I'm using a morph to cause this effect is there a way to keep the size of each frame in the film strip constant?

SplineGod
11-28-2005, 11:24 AM
Are any of the bones changing size ?

mightpeebler
11-28-2005, 12:55 PM
Are you talking about the bones in the motion path? If so they don't appear to be changing size. I created a uv map for the texture, and when I apply the morph to the polygon that I used for the streaming effect the UV remains constant.

mightpeebler
12-01-2005, 10:28 AM
I thought that the stretching was due to the UV map I was using, but I tried to use a planer projection and modify the scale, position, and rotation so that the frames were spaced out right. This caused even more stretching. Is it possible to have an object stretch and to have the texture remain the same or do I need to totally re-think the animation?

SplineGod
12-01-2005, 02:26 PM
If your object deforms in some way the texture will to. You can use world coords on the texture but getting it to stay aligned with the object might be a real pain. The trick is to move the filmstrip along a path without stretching it. You should be able to do this
morphing it along a chain of bones or using something like DStorms free Trailer plugin.