Bullet hits on specific body areas?

I have a couple of armoured figures in a scene and want them to be peppered by bullet hits (like ricochets or pings).

Obviously I only want them to appear in the layer where the figures are.

What's the best way to achieve that?


  • Triem23
    Triem23 Posts: 20,292 Power User

    I assume you're using a stock footage bullet hit?

    Do you know how to set up the particle sim to use a video as a particle texture? I'm thinking if you set up a sim to spawn bullet hits you can animate a point emitter. Using an AK-47 as an example, an AK fires 10 rounds/sec. Set up the emitter for 10 particles per second and animate that to move over your figure. You could even set up this particle sim on its own, save a oa project and use "Import Composite Shot" to bring the sim into multiple projects. Build once, reuse forever!

    Ok... So, in the Particle Sim Emitter>Particle System>Appearance you'll be able to select a texture of "None," "Built-in," or "Layer." A Layer can contain a video file. You'll have options for "Static," "Random," or "Animated." Animated uses the whole video. You'll be able to set up a start frame and range of frames. If the bullet hit is pre-keyed, or on black you can use the layer directly (set the Particle Blend Mode to ADD if it's on black). If the hit is on green you'll have to key it in a Comp and use the embedded comp as texture source.

    Make sense?

    There are other ways to approach this, but I like the particle sim. Once that's set up it's fast to reuse and as simple as just moving the point over the impact point. You could even set up multiple emitters for a hit-spark, puff of smoke, maybe some debris. They'll all be linked...

  • DafterThings
    DafterThings Posts: 985 Enthusiast

    Thanks Mike

    Yes... took me a while to understand but that's what I need to do: Move the emitter over the figure.

    I was hoping I could, somehow, limit the creation of each bullet hit to spawn in a defined area but I had no way to define that area other than masking the figure.

  • Triem23
    Triem23 Posts: 20,292 Power User

    Hey, animating a moving point with a particle emitter takes a lot less time than stop motion!

  • FilmSensei
    FilmSensei Posts: 3,156 Expert

    @DafterThings You could just shoot the figures with a real BB gun! Practical effects! 😁

  • tddavis
    tddavis Posts: 5,222 Expert

    @FilmSensei To scale, a bb would more like an .75 musket ball, if not a cannonball 🤯🤣

  • DafterThings
    DafterThings Posts: 985 Enthusiast

    I wonder how small you can get squibs 😀

    Seriously, I will have 5-6 people firing for 30 seconds so an emitter per shooter moving across the figure should do it.