Paint effects exact end for flow animation

[zaphands]

Hi all,
I'm using flow animation on painteffects brushes which I want to start growing at 0 seconds and END dying (the help only mentions start dying) at 1 seconds. Does anyone know how to set the parameters? I think that the length of the stroke should be taken into account, but I'm not sure and I can't get the exact animation I want.
For example, in the screenshot I attached, on top you can see the stroke with flow animation at time=1sec, and on bottom you can see the full length (spans = 26) stroke without the flow animation. As you can see, the start of the flow animation doesn't even reach the end of the stoke by that time. How can I tell when does will the tubes die exactly?
Thanks in advance

[bjohnston]

Are you looking to flow the texture  on the stroke or grow the stroke along a path?

[zaphands]

Grow the stroke along a path (it's curve).

[bjohnston]

Have you tried animating the min and/or max clipping under the EndBounds tab on the shape node?  The flow animation is primarily for controlling the texture scrolling and gap animation on the brush tubes, not its growth along a curve.

[zaphands]

There are two problems with end bounds (clipping):
1. Using them causes extreme memory leaks from maya and it (and sometimes even windows) crashes after a few minutes of work.
2. While it's true it is used for growing tubes, on the brushes I use the tubes tend to grow along the curve (though I don't know in what manner exactly). So It's not quite the same visual effect of growth I'm looking for in the clipping. Clipping changes the geometry of the tubes in a non smooth way.

[bastardloud]

Hey,

So I see your time set for .1 seconds I thought that 1 = 1 second not .1? One tenth of a second = 2.4 frames@24fps. This will not really give you much time to play with anything. I don't really see what you problem is. So I'll just try and give helpful suggestions. Can you explain your goal?

1. You can keep adding seconds to your "End Time" Attr untill you get the desired effect. 

2. Again not knowing what you really want you can crank the "Flow Speed" up to 50 or 100

3. Could this be solved by using the "Gaps" Section of Paint Effects. 

4. Can you just convert to polygons and then plug a ramp into the tranparency of a shader and just animate the ramp?

[zaphands]

My goal is to create a smooth animation of a painteffects stroke advancing along it's curve, not using clipping from the reasons above.
In the screenshots above I try just to convey the problem, but it's a typical case to what I'm trying to acheive.
my endTime is set to 0.1 secnods only for this example. I expect the animation to be in a total length of 1 second, so this means that the visible length of the stroke should be 10% of it's curve. Unfortunately, the animation doesn't take exactly 1 second since it's duration depends on the flowSpeed. So my problem of perfecting the duration of the animation is reduced to determining the flowSpeed. I noticed that to create an animation length of 1 second with different strokes in different lengths requires setting different flowSpeeds, so I hoped that there's a constant ratio between the length of the stroke's curve and the flowSpeed, but apparently it depends on other parameters as well. I couldn't find and formula to determine the flowSpeed so the animation would take the expected time.
Regrading your suggestions:
1. True, but this would be different for each stroke and I couldn't find a rule. I'm trying to apply this to many strokes and I can't do this manually.
2. If I don't find the exact flowSpeed value, I wouldn't get the exact duration I want. If the flowSpeed is too high then the stroke would disappear too quickly.
3. No. Gaps operate on the tubes, not on the stroke.
4. The visual quality of the painteffects when reduced to polygons is too low for me.