View Full Version : Animate a growing line

05 May 2009, 12:40 PM
Iīll try to explain what I wish to do.
A line growing from the left side and while itīs growing the camera pans with it.
The line shall be able to divide it self into two seperate lines (to create a outline of an object) and coutinune as one after.
I wish to rotate and pan the camera, for an example as in AE.

Iīll tryed the plugin Trapcode 3D Stroke in AE, but it needs closed masks.

I wich to have a open line to animate.

(I use Adobe CS3 incl AE, Premier, Flash, 3Ds Max).

Any thoughts or plugins to recommend?


05 May 2009, 08:58 PM
You basically just need to draw your line, create a mask and make the mask grow from left to right. If your same is more complicate try breaking it up into several layers and time your masks appropriately.

You can really test this easily in flash but if you want to do it in AE I dont see any problem using shapes and layer masks.

If you need to have a camera following it, it might be difficult to show that the line is growing or being drawn. You might want to put a textured BG in there to show some background motion.

Check out the new trailer for the Princess and the Frog, the opening has this draw effect and it looks pretty good.



05 May 2009, 04:00 AM
Another technique that might be useful is to animate an alpha mask. For Blender there is a tutorial on the TexMesh feature which is used to create a burning fuse. The alpha-mask switches quickly (but not quite instantaneously) from transparent to opaque, and it's then animated down the length of the cord. So, the entire cord is present the entire time, but most of it is invisible (or not).

05 May 2009, 07:16 AM
Thanks for the input.
I have a rather complexed scene, so I hoped there were another way to do it.

More like Trapcode 3D Stroke, but whitout the closed masks.

Thereīs a thought, I could do it in Max and export the alpha to AE.

Any more suggestions?

05 May 2009, 04:55 PM
Have you tried using the AE native strokes effect on a AE generated mask? Create a black solid, use the pen tool to create the line, add the stroke effect to the solid layer, set the solid layer to screen (if over a background layer), set the solid layer to a 3D layer, add a camera and animate the stroke through its effect controls. You'll be able to animate the camera to follow the stroke. Use multiple strokes to make the line splite, etc.

If you have access to Maya you can animate paint effect stroke attached to curves to do this very effectively.

Good luck

Buzz Chambers

05 May 2009, 07:21 AM

Pretty much the way I did it, but I used the Trapcode sroke instead. It worked fine without closed masks.

Maya, long time ago, but you gave me an idea for 3ds max.
Always nice with new input,

thank you..

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