Some advanced Particle Simulator questions

KeeganKeegan Website User Posts: 294 Just Starting Out
Hello!
I am working on a new short video and almost all of the VFX are going to be done with the particle simulator. I have some specific questions based on the effects I am trying to achieve. I assume most of the people reading have a much better understanding of how the Particle Engine works, so bear with me! :)
Okay, first off, I have a particle effect and I am trying to make the particles white and purple. I want this color to be applied at random, so some are white and some are purple. The 'color variation' knob makes them all different colors. Are there parameters I can set to make my particles vary between specific colors?
Second, I am trying to achieve an effect where a particle is emitted and then that particle cycles through a series of images. More specifically, I am emitting a butterfly and am trying to make it appear to be flapping its wings. I have 3 particle textures that outline the basic 'flapping' cycle of a butterfly. I thought maybe a .gif image would work, but I have no idea how to do that.
Third, I am making a kind of particle stream and I wanted to make it distort along its path. I know hitfilm doesn't have a brush feature (yet? ;) ) so I was wondering how I would animate a distortion effect that only affected my particle stream.
Lastly, is there anyway to make particles behind/beneath a plane disappear? I am trying to make a dome of particles and am using the sphere emitter shape. It really ruins the effect if you can see the particles going beneath what should be the ground! xD
That is all! Thank you in advance for your help! :))

Comments

  • OrangePekoeOrangePekoe Website User Posts: 478
    edited June 2012
    Hmm lots of good questions here,
    1) I'm not sure if there is a specific setting to control the particles colors (limiting the choice to two colors). I'll take another look when I get back home. However, you could create two particle systems, link / parent there emitter movements together making one white and the other purple, offset the timings and movements so the particles disperse at different times.
    2) Good question, I was curious if we could control the cycle of images for a given particle over time as well. I haven't checked if animated gif's are usable or not but if they are that would be great!!
    3) What type of distortion effect are you looking for? Something similar to a displacement / heat wave effect that only affects the particles?
    4) Depending on the angle of the shot, if it's a side profile shot you could just change the timing of the 'life' so that around the time the particles hit the ground they 'die off'. You could also try masking the area which you want the particles to stay within so that once the particles move outside of the mask they disappear.
    Hopefully that helped.
  • AxelWilkinsonAxelWilkinson Staff Administrator, Imerge Beta Tester, HitFilm Beta Tester Posts: 5,242 Staff
    1. The best way to have two distinct colors in the same effect is to use two particle systems. I used this exact technique in creating the Time Tunnel in this tutorial from last week:

    Once you get your first particle system set up, just duplicate it, and change the color for the second one. Then shift the Seed a bit so you get the particles in different places.
    2. Animated sprites for particles are definitely something we are looking into for the future.
    3. Depending on the distortion you need, you might be able to achieve it simply by placing cube deflectors near/in its path, and controlling the particle movement with them.
    4. Placing a plane through the middle of the sphere will hide half of the sphere from view. Its just a matter of adjusting the angle of the camera or of the plane and effect, so that it looks correct in the frame.
  • KeeganKeegan Website User Posts: 294 Just Starting Out
    Thanks for the responses, guys! :)
    1.) Got it all sorted out! Thanks!
    2.) I hope that feature gets implemented! I was thinking maybe I'd try 3 particle systems with all 3 animations as textures and identical seeds. To make them appear to animate I'd fluctuate the opacity of each particle system. This is all in theory, so I have no idea if that would work!
    3.) Displacement is what I am looking for. I want it to look like the light is bending so the particle stream itself, not the individual particles is visibly skewed and twisted, making it look like the light it being bent.
    4.) Excellent! That worked like a charm!

    One (hopefully final) question: Are there any ways to simulate a sphere shaped deflector? I wanted to shoot these particles at the particle dome I mentioned previously and have them bounce off and scatter about as if they were colliding with a geometric sphere. A flat deflector bounces the particle straight back at the emitter if it is perpendicular to the stream and any angle variation of that plane only deflects the particles in one direction.
    My quick fix was to have the particles disappear at the point of impact and use another emitter at that point to shoot the particles in a 180 degree dome (using the 'cone' emitter type). This doesn't work 100% because its hard to hide the fact that there are 2 distinct emitters.
    Here is a quick demo of what I am talking about. I attempted to use lens flares to cover up the point of impact but it's not the same xD
    [attachment=306:DomeCollisionTest.png]
    Thanks again for all the feedback! Love this community. :D
  • SimonKJonesSimonKJones Moderator Website User, HitFilm Beta Tester Posts: 4,450 Enthusiast
    1. While multiple particle systems works, the best way to get multiple colours into a system is to use the Lifetime controls. For the particle system in question, go to the Lifetime panel and the Color property. Change the type to 'Random'. Then add tabs with all the colours you want to use, and activate the 'key frame only' option. Each particle will pick one of the keyframed colours at random when it is born. Nifty, eh?
    2. Animated textures aren't possible in HitFilm 1. It's definitely something we want to add in future and we've got some pretty epic ideas for implementing such a feature.
  • KeeganKeegan Website User Posts: 294 Just Starting Out
    Simon, you're great. Its as if you are some kind of expert. :P
    1. This is perfect!
    2. I've got massive faith in FXhome, always have. Can't wait to see where the road leads to next. :)
  • spydurhankspydurhank Moderator, Website User, Ambassador, Imerge Beta Tester, HitFilm Beta Tester Posts: 2,829 Ambassador
    Nice, I just rendered out an image sequence of a turbulent smoke sim from Blender to use in HitFilm's 3D particle engine. I was very surprised to realize that particles were not cycling through the animation. Not a big deal though. I'm sure the guys will add this feature whenever they're able.
    Another thing that surprised me is... HitFilm can import high res images to use as particle textures. I rendered out a smoke sim in Blender at 1920x1080 and HitFilm handled it very well. I then rendered out the same smoke sim at 200x250... again, I was surprised because it looked really good. HitFilm blows me away every day. :D
  • OrangePekoeOrangePekoe Website User Posts: 478

    1. While multiple particle systems works, the best way to get multiple colours into a system is to use the Lifetime controls. For the particle system in question, go to the Lifetime panel and the Color property. Change the type to 'Random'. Then add tabs with all the colours you want to use, and activate the 'key frame only' option. Each particle will pick one of the keyframed colours at random when it is born. Nifty, eh?
    That's a great tip!
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