Jump to content


Photo

Particles That Follow A Path.... Again.


  • Please log in to reply
16 replies to this topic

#1 vidjuheffex

vidjuheffex

    Advanced Pig

  • Adv Members
  • PipPipPip
  • 33 posts

Posted 22 February 2013 - 11:17 AM

So I've been searching around and have reached a few dead ends. I've found several tutorials that show show to get particles to emit from a point on a path, like trailers. This is not quite what I need. I need a fixed emission point whose particles follow along a path as they travel. There have been references to a tutorial by Arty which seems promising but I cannot find that, as well as a broken link to this forum for a solution from Eric so I am fairly confident that this is out there. Any help on this would be greatly appreciated.

#2 vidjuheffex

vidjuheffex

    Advanced Pig

  • Adv Members
  • PipPipPip
  • 33 posts

Posted 22 February 2013 - 11:30 AM

Additional info:
This can be a 2d solution as the move is linear and I should be able to project it on a card.

#3 ChadCapeland

ChadCapeland

    Flying Pig

  • Adv Members
  • PipPipPipPipPip
  • 1,975 posts

Posted 22 February 2013 - 01:04 PM

Convert a 2D path to an image (basically XY coordinates along the length of the spline in time as RG values in the image X). Then read in that image to a pCu or pCF and sample the pixels (or the partial derivative) based on the particle age.

#4 vidjuheffex

vidjuheffex

    Advanced Pig

  • Adv Members
  • PipPipPip
  • 33 posts

Posted 22 February 2013 - 01:28 PM

Okay.
1) Thanks for the reply
2) It's a bit above my pick-up-and-run-with-it level especially with this toolset so I hope you don't mind some questions. :)

Question 1: This sounds a lot like http://www.pigsfly.c...?showtopic=1966
If so then it is emitting from the path, not emitting from a fixed emiiter and being "flowed" along the path.
If not, what step is different between what you described and the eyeon-video that would cause the behavior change.

#5 ChadCapeland

ChadCapeland

    Flying Pig

  • Adv Members
  • PipPipPipPipPip
  • 1,975 posts

Posted 22 February 2013 - 02:26 PM

Check out...
http://research.anat...tive-smoothing/
http://research.anat...hing-animation/

This may be of some lesser use...
http://research.anat...ition-sampling/

#6 ChadCapeland

ChadCapeland

    Flying Pig

  • Adv Members
  • PipPipPipPipPip
  • 1,975 posts

Posted 22 February 2013 - 02:34 PM

Holy crap, that was easy.

px=getr1b(age,0)
py=getg1b(age,0)

I'll do a blog post on this technique shortly, or if you're in a hurry email or pm me.

#7 vidjuheffex

vidjuheffex

    Advanced Pig

  • Adv Members
  • PipPipPip
  • 33 posts

Posted 22 February 2013 - 03:36 PM

Sorry, pasted the wrong link still working through your other stuff. Will let you know if when I get stuck. Thanks.

#8 vidjuheffex

vidjuheffex

    Advanced Pig

  • Adv Members
  • PipPipPip
  • 33 posts

Posted 22 February 2013 - 03:51 PM

Okay, question(s). My 2D spline is Paint node with my polyLine drawn on that.

"Convert a 2D path to an image (basically XY coordinates along the length of the spline in time as RG values in the image X)."

What do you mean by "in time", the path is not animated at it is a consistent path I want my particles to animate. not emit, along.

I guess with the degree to which this is not clear to me, an example comp would be the most useful if at all possible. I'm just not understanding the above-quoted statement, the pCustom stuff seems pretty clear. Thanks.

#9 ChadCapeland

ChadCapeland

    Flying Pig

  • Adv Members
  • PipPipPipPipPip
  • 1,975 posts

Posted 22 February 2013 - 04:46 PM

Ah, Eric's comp is based on the concept I had in the blog post, so yeah, he's gone and done what I was going to show you, so you should be all set.

#10 vidjuheffex

vidjuheffex

    Advanced Pig

  • Adv Members
  • PipPipPip
  • 33 posts

Posted 22 February 2013 - 05:18 PM

Yes but unless I am mistaken, the emitter is moving in these examples, no? Leaving behind a trail of particles. I need the Emitter to stay put, think a teapot, the steam always leaves the spout, I just need to specify the path the steam takes as it is not procedural but instead a bit weird and specific. I've attached a still from Cinema 4D's Thinking Particle Follow Spline Example. The blue extruded shape is the path to follow, and the airplanes always emit from the same (selected and visible with axis) point, they follow, but do not emit from the blue spline. As such, the blue spline is not animated so it doesn't have a "coordinate" at time. Is this possible in Fusion?

Nevermind, it wouldn't attach.

#11 vidjuheffex

vidjuheffex

    Advanced Pig

  • Adv Members
  • PipPipPip
  • 33 posts

Posted 22 February 2013 - 05:22 PM

https://skydrive.live.com/redir?resid=EE631A5F507BC8BE!29864 here, just as an example

#12 Dunn

Dunn

    Flying Pig

  • Adv Members
  • PipPipPipPipPip
  • 303 posts

Posted 22 February 2013 - 05:46 PM

Is this maybe what you are looking for :



#13 vidjuheffex

vidjuheffex

    Advanced Pig

  • Adv Members
  • PipPipPip
  • 33 posts

Posted 22 February 2013 - 06:01 PM

Close, we saw that video and it crossed our mind to try that approach, it's just not precise enough. The issue is this steam goes off screen on both sides, then we track right, over to the source of the steam. Then the steam is supposed to stop emitting but retain its tapered end as that travels along the path. I think we can get it with a mesh shape but that means we have to model mesh shapes for all 4 times we do this, and a part of it feels like we're killing a fly with an armored tank. Currently, the plan is to use the motion path feature in After Effects particular and render out to a card in Fusion as it seems this is a missing feature.

#14 Dunn

Dunn

    Flying Pig

  • Adv Members
  • PipPipPipPipPip
  • 303 posts

Posted 22 February 2013 - 07:02 PM

Okay, maybe try this.. http://native-newmed...ly/writeon.comp
i´m using a text Plus tool for this.. yes they are not particles but maybe you can get way by duplicating it or so.

.. just Trash it if its not what you looking for or wrong direction ;-)!

#15 Gringo

Gringo

    Associate Administrator

  • Adv Members
  • PipPipPipPipPip
  • 1,455 posts

Posted 25 February 2013 - 04:43 AM

Another way to make the particles fly along a 2D path:
http://www.pigsfly.c...976




0 user(s) are reading this topic

0 members, 0 guests, 0 anonymous users