VFX Graph - Rotate 3D, how to make particles rotate around center where they spawned, not the current center of a moving object?

Unity Engine
, , ,
1

Hi all,

I have some graphs set up to use Rotate 3D > Position (update block) for a spiraling effect to ‘wrap’ characters in trails/particles for spell effects. This setup works great when the target is stationary, but not when moving. I am not good at figuring out very technical things though, so I have come here for help :slight_smile:

The ‘problem’:

  • World space position / local space rotation center: when the character moves quickly, the particles swing out wildly trying to keep up with the new rotation center
  • World space position / world space rotation center: The center stays at the same point in world space, so the particles always rotate around it

Solution needed:

  • How to make the rotation center for each particle stay at the location it was at, when the particle was spawned? The effect I intend is that the particles fall behind the moving character, but continue their rotation/orbit in world space as they finish their lifetime, not trying to chase the currently moving rotation center. So somehow, I need to tell it to grab the ‘Rotation Center’ that existed at the moment the particle spawned, and use that?
  • Or if this isn’t possible using Rotate 3D, what should I do to get the desired spiraling effect that gets left behind in world space?

Thanks!

Here’s the Rotate 3D setup I have been using

image
image773×276 25.6 KB

2

What you need is exactly as you said - world position that existed at the moment of spawning.

I assume every particle has it’s own rotation origin, so you need to cache parent position in particle attribute.
For example you can use ‘targetPosition’ (or custom attribute) and set it to current world position when particle is spawned (Initialize context), then retrive it later and feed to Rotation Center.

Something like that should work:

obraz
obraz982×529 42.4 KB

3 Likes