Orbit through forces?

Dimipapa
Dimipapa Posts: 431 Enthusiast
edited September 15 in Post-production techniques

I played around with it just a little, but I wonder if you could get particles to orbit around the forces sphere or cube of influence. If it works like actual gravity it would have to be a pretty perfect speed and trajectory to get it to work since you can't make any adjustments after the particle is born.

Comments

  • Triem23
    Triem23 Posts: 20,188 Power User

    You can get an orbit, but, as you said, you'll really need solid starting vectors to make it happen.

    Amusingly, waaaay back with HFU2 I was playing around trying to get a decaying orbit for a "black hole" or "vortex," and accidentally ended up with this. It's all driven by a single gravity force. Couldn't have hit this form any better if I'd been trying for it.


  • Dimipapa
    Dimipapa Posts: 431 Enthusiast

    interesting, so it is possible, just not really worth it.

  • Triem23
    Triem23 Posts: 20,188 Power User

    Depends on what you're trying to do. But, since an entire particle sim layer can be transformed in 3D space after calculation, I'd probably just rotate the particle sim layer on an axis and fake it. Since most of what I've seen from you is more anime style, faking the orbit by rotating the sim is probably the way to go, while using Depth Layer settings to handle occlusion with other layers.

    I dunno why I'm thinking you wanna rotate particles around a character, but that's my first guess. So, if the character layer is on a 3D plane you should be able to Depth Layer the particle sim with the character for occlusion.

    I also think the forces are simplified. Gravity has a distance falloff in the real world, but I'm pretty sure the particle sim "Attract" force doesn't.

  • Dimipapa
    Dimipapa Posts: 431 Enthusiast

    Yeah I would just use rotating points if I wanted it around a character. I was just curious if this was possible. I've been watching these technical looks at the code of old NES games makes me wonder about everythings nuts and bolts. Speaking of my anime BS I just tried to recreate the HUD from Street Fighter Alpha 3, it came out pretty good. Did it with a bunch of tracing with planes and masks.


  • NormanPCN
    NormanPCN Posts: 4,298 Expert

    I also think the forces are simplified. Gravity has a distance falloff in the real world, but I'm pretty sure the particle sim "Attract" force doesn't.

    I agree. Constant force, any distance from force center point. This is a reason why particles do not move around and/or by a force cuboid like they should. Years ago in a Hitfilm wishlist post, about fixing/updating the particle sim forces, I linked a few seconds of video from the particle sim in Resolve. Showing how I think force should work in Hitfilm.