You can animate the stroke path being painted (or revealed) by keyframing the Max Clip value.

The following procedure describes just one way of keyframing. For other methods, refer to the Animation guide.

To keyframe the stroke being painted (or revealed)

1. Click the Auto keyframe toggle (the key icon at the bottom right corner of the Maya main window) and move to the first frame.
2. Select the stroke you are animating.
3. In the Attribute Editor, click the strokeShape tab and expand End Bounds.
4. Right-click the Min Clip and Max Clip boxes and select Set Key.
5. Set both the Min Clip and Max Clip values to 0.
6. Move to the last frame and set the Max Clip value to 1.
7. In the scene view click the Play Forward button to check that the animation is working the way you want it to.
8. Render the animation. See Render a scene with Paint Effects strokes.
   Note

   You can achieve other effects by keyframing different permutations of the Min Clip and Max Clip values. For example, you could animate a stroke gradually or disappearing from the beginning of the stroke, or from both ends of the stroke.