Snow Swirls

stbo
stbo Posts: 61
HF2 Ultimate user
Looking for suggestions as to how I might make 'snow swirls' - something like the swirls that you see the Elsa character in 'Frozen' 'throw' out of her hands.
I understand how to make a set of particles follow a traced path, but ideally I want the swirls to 'fan out' in some sort of geometric pattern - and I have been experimenting for some time and I must be missing something.  
the video is available on Youtube here:
https://www.youtube.com/watch?v=moSFlvxnbgk&feature=kp
See around 1.08 and also 1:18.
It seems like I almost have to generate a path for each snowflake individually, then track the path, then use that tracked path to attach the slowflake to, but that seems way too cumbersome and error-prone.
Would anybody have any suggestions how I might achieve something similar? I am aware of the complexity of the original - there is a fantastic article on the sequence over at fxguide.com - well worth a watch - but I would like to achieve sometime similar if possible.
Many thanks,

Comments

  • rgbii
    rgbii Posts: 965 Just Starting Out
    You'll need to do multiple emitters. The middle seems to be the brightest and biggest particles and the lest amount of travel from the original path. I'd probably do at least three emitters traveling together (attached to a point) for the main section of each. Each emitter creating smaller, but more particles that travel farther from the path.
    It might help myself and others to know what to suggest by knowing what you've got so far. Can you post an example?
    I only watched the two examples you mentioned, and nether showed the snow swirls after a few seconds. Do you plan to do the same, or will you have them drop or dissipate in some way?
  • SimonKJones
    SimonKJones Posts: 4,448 Enthusiast
    Also, looking at the swirls, there appears to be quite a lot of warping going on - whether that's just a side effect of the techniques or whether they applied some post-processing distortion I've no idea, but adding on some warp (vortex displacement warp?) to the particles could help.
    I think the trick here is going to be in combining full-on particle simulations with clever animated particle textures.
  • stbo
    stbo Posts: 61
    OK, bearing in mind I am really new to this....
    Here is my first attempt.  I found Simon's excellent tutorial on creating 3d animation rigs and followed it.   Once I got the 'Orbit/Orbit A/Orbit B' concept clear in  my mind I see now how it works.  I also see now why multiple emitters would make more sense.
    I change the particle texture to a small 90x90 snowflake.  I also used the 'Movement Variation' properties to cause the snowflakes to move in a more random trajectory once they were emitted. 
    If anybody has an opportunity to review the attached project (with png of snowflake) I would welcome some answers to the following questions:
    1.  At the end of the 10 seconds the emitters keep on emitting.  What is the correct way to stop the emitters emitting at the end of the effect.  Given my final keyframe is at 10 seconds and the Movement/Life property is set to 5 seconds I also need approx 5 additional second to allow the snowflakes born at 10sec to die  at 15 seconds.  I thought it might have something to so with some lifetime controls but I cannot see how..
    2. I wanted to have two sets of opposing snowflakes, so I created another point, set the turns to -3 to cause it to rotate in the other direction, then duplicated the various point layers and particle emitter, attached them to the appropriate layer and it seems to work.
    However, it is just too uniform.  I would appreciate some suggestions on how to make it more random.  I would like the snowflakes to disperse quicker, but still to last only 5 seconds once they are born.
    3.  What is the best way to 'offset' the start of the emission.   It would seem to make sense to delay the start of the various emitters by a small amount of time so they are not all travelling at the same time.  Should this be done at the point or in the emitter?  Again, I tried altering the acceleration properties of the individual emitters.  It does cause the individual snowflakes to move, but it is not what I am trying to achieve.
    Any advice/suggestions are much appreciated.
    Many thanks.
    stbo.
  • Nate066
    Nate066 Posts: 191
    edited May 2014
    1. You can either keyframe the active property under the emitter general settings or you can keyframe the particle count to zero.
    [attachment=959:ref 3.PNG]
    2. Change the seed to a random value for everything and mess with the movement variation. You could also use multiple snowflake textures.
    [attachment=957:Ref.PNG]
    3. You can use the time shift property for the two particle systems and for the rest just keyframe the active option under the emitter.
    [attachment=958:ref 2.PNG]
  • SimonKJones
    SimonKJones Posts: 4,448 Enthusiast
    edited May 2014
    I had a bit of a play - see attached project. I simplified it down to a single stream, but then added in a couple of additional particle systems. These were basically copies of the main one, but with smaller and more particles. I then added a turbulence force, and altered the mass of each particle system so that the smaller particles were affected more by the force. This results in the tiny particles being spun off from the main trunk.
    Crucially, I also threw on a couple of vortex displacement warps. I didn't put much effort into their placement, but they do help to add a randomness to the movement which is a bit like the Frozen stuff. With proper customisation and made to be a bit subtler it could look pretty awesome.
    It's a step in the right direction, I think - you're going to want to keep adding additional detail like that to get it looking right.
    EDIT: Here's a render:
    http://youtu.be/ula--Q4yJB8
    It's all waaaaaay too slow, obviously, and some of the warping is too extreme, but I like the overall look it's angling towards.
  • Triem23
    Triem23 Posts: 20,070 Ambassador
    Oooh, think I will download this project and dissect it!
  • stbo
    stbo Posts: 61
    Nate, Simon,
    Many thanks for all the suggestions (and the sample project).  it gives me a lot to play with and also to learn from.
    STBO.
  • rgbii
    rgbii Posts: 965 Just Starting Out
    Here's a quick test I did. Not perfect, but was fun playing with.  I used the default particle circles, so would probably look better with a proper texture.
    http://youtu.be/CLow76AOi3o

    [attachment=961:SnowSwirls.hfp]
  • stbo
    stbo Posts: 61
    Richard,
    Thank you - I love the 'drop' - I hadn't thought of doing that, but it really works...
    Stewart
  • KirstieT
    KirstieT Posts: 1,086 Staff
    Oh wow rgbii - I only watched Frozen a few days ago and I reckon you're onto something there!
    The drop is great - perhaps not lingering in the air for so long but being given off at all times while the shape is being created. Combining the 'magic' of Simon's with the practicality of yours could create something which is really similar. Just need to add some snowflakes now! :)
  • KirstieT
    KirstieT Posts: 1,086 Staff
    Alright, took 10 minutes out to play around and came up with this:
    https://www.youtube.com/watch?v=6Ou7Ik8-XmQ&feature=youtu.be
    Using some of rgbii's methods and Simon's idea of a vortex displacement (genius!). Warp was too extreme but it could get to something similar in the future.....
  • CalebK
    CalebK Posts: 435
    Wholly cow your a magician! Nicely done! You guys (especially Kristie)
  • CalebK
    CalebK Posts: 435
    I was playing around when simon's demonstration.... i found a really cool frame!
    [attachment=973:cool.png]