How do I animate a cylinder elongating horizontily over time while also moving up and down, as if the line is moving on a graph over time?

You could use the spline modeler, changing the length and envelope over time using keyframes in the timeline.

Chuck

You could also try a cylinder with a couple of bones in it- move the bones, let the cylinder deform. Markd

Thanks Chuck but I've been trying this for the last day. I extend the line by dragging the point along the axis, then set a key frame, this will work for the 1st point. To change line direction I then add a point on the line near the one I moved so the line will stay at that value. Then I continue extending the line by dragging to the next value and set another key frame. The line would look similar to this //_/. When I do this the line will not animated from point to point, instead it will track from the final point to the starting point. Is there a certain order to add points and set key frames? Does anyone know of a tuitorial?

Thanks Markd, But I need the line to start very small and grow smoothly along a fixed path. I can use the cloaking tool to hide line segments and uncloak them at keyframes but this is has too jerky an effect.

Is it like some sort of financial graph with a cylinder "pipe" being used instead of the red line? How about using an animated shader that "reveals" a pre-set stationary pipe via transparency.

Ah! I misunderstood. I thought you were talking ONE section. The transparency idea should work ok- although the rate may change some as the angle of your line does, depending on how you rig the shader. If you have Akuro's Potentializer, that would do the trick nicely (use a sphere to deform a plane permanently, shade the plan based on elevation. voila!) Markd

I've created all the points I'll need for the entire bar and set them all to the same starting point. Then I move them together along the same path, letting points stay in place along the way.

Thanks shonner: I've tryed this and it works, but how do you keep the all the points close enough together when you change direction of the line? Can can you stack the points on top of each other, or do you zoom way in to see the individual points? I'm able to drag all of them together and leave one point behind as I continue elongating the line, but this leaves a straight portion of the line containing the unused points that doesn't follow the direction of the line, especially the first couple changes of direction of the line. Thanks everyone for your help.