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Follow path? Particles? Help!

Posted: Tue Jan 02, 2018 1:57 pm
by pinar
Ok so I'm trying to animate something like in the video between seconds 0:52-1:12, and I'm having a LOT of difficulty doing it. I tried to create a shape and move it along the path, but it rotates when I attach it to the path and if I rotate it in frame 0, it goes crazy and rotates constantly between frames. This is the first time I'm using follow path in Moho, so I don't even know what I'm doing wrong :(

Honestly, if I knew how to do it, I would even consider doing it frame by frame. Any help is appreciated!

https://youtu.be/GxAFnXQ6YAU

Re: Follow path? Particles? Help!

Posted: Tue Jan 02, 2018 3:45 pm
by hayasidist
you're trying to do the sand I assume from the reference to "particles" in the headline.

try this as the basis of an approach.

make your vector sand particle exactly at the origin {0,0}
make your particle direction and gravity the same direction (i.e. +/- 270)
have free floating particles; off at start.
draw the path for the trunk's "business end" as one curve that goes up in an arc - flat for a moment - then back down

at the start of the sequence turn particles on
animate the particle layer along the path - rotate to follow path - have extra keys at the "top of the arc" to slow the motion
rotate the particle layer to get the sand to fall until the flat top of the arc when turn it rapidly through 180 (it's now inverted twice - one for the path and one by layer rotation)
at the top put in a noisy keyframe on its rotation to get the "shake"
turn off particles

to get sand to bounce off the elephant's back have a second particle layer that throws the sand up (i.e. 90) with gravity down (270)

to increase the sand fall consider multiple particle layers turned on/off as needed
experiment with duration / speeds / scatter...

hope that's useful. do say how you get on....

Re: Follow path? Particles? Help!

Posted: Tue Jan 02, 2018 7:10 pm
by pinar
Wow, that's a lot of info. Honestly, when I first read it, I was like "what language is this??!" But then I figured out how to make particles (thank you youtube :) ) And after that it made much, much more sense.

I didn't get this part though.
rotate the particle layer to get the sand to fall until the flat top of the arc when turn it rapidly through 180 (it's now inverted twice - one for the path and one by layer rotation)
And now I have more questions :D

I made 2 particles, one for the arc, and one for falling down on the elephants back. The arc one seems to be working ok for now. However, in the second one, when the particles are supposed to fall down, they're jumping upwards first and then falling down, even though both the direction and acceleration are 270. Any idea why that might be?

Also, is there a way to prevent the particles from falling all the way down to the frame? I just want them to fall a little bit, until the elephant's back, but they keep on falling.

Oh, and thanks for the help :) You have no idea how much I appreciate it!

Re: Follow path? Particles? Help!

Posted: Wed Jan 03, 2018 3:52 am
by hayasidist
at the top of the arc you want the sand to fall down. With "rotate to follow path" but without rotation of the particle layer, the particles will (should!)be pointing upwards, so it's necessary to flip the particle layer so the particles come out pointing down (and we need rotate to follow path so the sand sprays out as the trunk arcs.)

a jump up first is possibly because you've got particles on at start - if you have "free floating" and don't turn particles off before you rotate / move the particle layer, the particles are generated with the initial (frame 0) settings.

adjust the speed / particle lifetime to have them disappear at the appropriate time.


good luck! (I'll work up a short demo in the next few days if that's not clear)

Re: Follow path? Particles? Help!

Posted: Sat Jan 06, 2018 9:43 am
by pinar
Got it! Thanks again for the help and opening a whole new door for me (particles) :D

Re: Follow path? Particles? Help!

Posted: Sat Jan 06, 2018 11:40 am
by hayasidist
glad to have been able to help. Particles are pretty versatile - you can animate the individual items for more effects. If you're interested in a few examples - in this: https://www.youtube.com/watch?v=ywI5SZjuVaY there are particles for the falling snow; the smoke rising; the sparkle in the fairy wings; the "laser" she fires; the "flame" on the ice surface; the steam rising; the flashes in Santa's dome.

Re: Follow path? Particles? Help!

Posted: Sat Jan 06, 2018 6:40 pm
by pinar
Hold on, your name is Hayat? Huh.. that means "life" in my language :)

The animation is pretty cool. I may need to follow you on youtube :)

Thanks again!

Re: Follow path? Particles? Help!

Posted: Sat Jan 06, 2018 7:17 pm
by hayasidist
pinar wrote:Hold on, your name is Hayat?
nope - she's my better half ... https://youtu.be/rPNf1tf3_XE