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View Full Version : PaintFX-Loop Brush Animation How To?


circusboy
03-04-2008, 07:26 PM
I just don't get it.
And the docs seem to state the obvious and stop.
-shot 100 frames long
-Flow speed 5
-30fps
-start time 0
-end time 2

(lets say I'd like it to loop twice within 100 frames)

If I have a stroke with flow animation and then I apply
'Loop Brush Animation' it just seems to *break everything*.

-Stroke time and Time Clip uncheck
-Flow speed goes fro 5 to 0.480
-No property seems to be added
The stuff growing off the stroke is static now.
So where is my loop?

Checked back to v7 its the same behavior.
-help?

Duncan
03-04-2008, 11:11 PM
The looping is accomplished by attempting to modify your settings so they seamlessly loop within the defined "cycle frames". Basically it adjusts the flowspeed and and turbulence speed to accomplish the looping. You can't have timeClip or stroke time, because these effects cannot loop by their nature.

This is generally useful for things like looping flames, or having trees blow in the wind in a loop (say for creating an animated sequence for a sprite).
It also works for effects like rain, bubbles and things where one is using flow speed with gaps.

How would you expect a growing effect to seamlessly loop? In general such loops have an overall static effect. I suppose a growing branch could get skinny or fade out within the loop cycle( or reverse direction and shrink).

Also are you sure that the end time of 2 does what you think? Most people get confused on that one and think it is the time at which the object is fully grown. Rather it is a time at which the stroke stops emitting, and thus the object will disappear from the bottom up after this time. Setting the end time does not make sense with plant growth, but it can be useful if you want to do effects like emitting a lighting bolt.

Duncan

circusboy
03-04-2008, 11:25 PM
How would you expect a growing effect to seamlessly loop? In general such loops have an overall static effect. I suppose a growing branch could get skinny or fade out within the loop cycle( or reverse direction and shrink).

Duncan
Thanks Duncun.
This is pretty much what I had visualized indeed-a loop growth animation.
A request then-not sure how trivial.
BTW its hard to tell from the parameter labels and even the docs what the effect is
restricted to.

Duncan
03-04-2008, 11:48 PM
Looping plant growth will be tricky. You could create a grow sequence where you keyframe the tubeWidth and leafSize values to zero at the end of the sequence. Then duplicate this stroke but animate the same sequence such that the timing is offset by half the sequence length.. basically the first and last halfs of the sequence should be swapped. Note that if desired this second sequence could be a different animation.. it need not be the same as the first. The key is that the second growth fades to nothing and restarts in the middle. This way the overall growing looks more continuous. One can introduce additional strokes with time offsets of 1/4 and 3/4, to make the growth look more continuous( instead of pulsing at the loop value ).

Note that for the growth animation (timeClip+flowSpeed) doing the time offset can be accomplished by breaking connection on the brush time attribute and keying by hand. Note that your keyframes on tubeWidth would need to be shifted as well.

Duncan

circusboy
03-05-2008, 01:49 PM
Thanks as always Duncan-

Turns out a more standard flow might be the ticket after all.
But this advice is very useful.

So is there gonna be a nPaintFX someday?

yenvalmar
03-06-2008, 05:03 AM
i like it, maybe "nsoftbodies" could be next ..

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