Bug / Crash Force Zone not working

[OneGuyProd]

Hi. So I been trying to have a fluid floating around the player by setting the gravity of the solver to 0, also, to cover the player collider shape, I attached a force zone to it. The problem its that it is not working at all and it is showing a message in the force zone component "Error: Could not retrieve a property". However, I´m attaching a video to this post to show you the set up of all the stuff.

For clearance, the buyoancy from the liquid blueprint is set to 0.

https://youtu.be/PD8gLi1eC-Y (uploaded on youtube because of the page did not accept an attachement directly in the post).

[josemendez]

Hi. So I been trying to have a fluid floating around the player by setting the gravity of the solver to 0, also, to cover the player collider shape, I attached a force zone to it.

Hi,

That's not how force zones work: force zones only affect particles inside of them, which in your case means fluid needs to be inside the player for the force zone to do anything at all.

Your force zone is also set to radial, which means it will apply a force away from the surface of the collider and towards its center. So instead of floating around the player, all fluid emitted inside the box will clump at its center - which is the behavior shown in the video.

If you want the fluid to orbit around the player, use a spherical force zone set to vortex mode, that encompasses the orbiting area (which I think should be considerably larger than the player). You could use additional force zones to control how close the fluid is allowed to get to the player, and how fast it should orbit.

let me know if I can be of further help,

kind regards

[OneGuyProd]

I tried that setup and the result is shown in this video: https://youtu.be/mVxphj-gdIE

The emitter is inside the collider of the force zone, the force zone is setted to "Vortex" and the collider to follow for the force zone is bigger than the player itself

[josemendez]

I tried that setup and the result is shown in this video: https://youtu.be/mVxphj-gdIE

The emitter is inside the collider of the force zone, the force zone is setted to "Vortex" and the collider to follow for the force zone is bigger than the player itself

- The force zone is still extremely small, fluid goes outside of it almost immediately after being emitted. You need fluid to stay inside the zone for long enough to be affected by the force and have its trajectory altered. The larger the force, the faster the fluid will accelerate depending on its mass. This brings us to the second issue:

- The force intensity is 100, but what's the mass of your particles (shown in the fluid blueprint)? Acceleration = Force/Mass, so mass is large, large forces will result in very little acceleration. There's no way to tell if 100 is a large enough force to move the fluid without knowing its mass. You may want to switch the force zone to "acceleration" instead of force if you want to directly apply an acceleration, regardless of the fluid's mass.

- Another obvious issue is that the emitter is pointing outside the force zone.  A vortex will make particles rotate around the force zone's local Z axis, but if fluid is moving towards the edge of the force zone, rotation won't prevent it from going outside the zone. This is because in absence of a force that opposes movement, objects will just keep moving.

If you want to confine the fluid inside the force zone, you may want to use damping to reduce velocity in the direction of the force zone's surface: set the force zone's damping direction to "Surface Direction", and use a high damping value, like 100. You could also use a second force zone set to "radial", that acts like a gravity well attracting fluid towards the player.

- Keep in mind that collision filters only affect particles. In the video you seem to draw attention to the fact that the player's collider is set to collide with everything except category 15, and Sphere_Coll is on category 15. Colliders cannot collide against force zones (it wouldn't make any sense) so this doesn't matter at all. As long as the force zone collider is on a category that the fluid can collide against, it's all good.

kind regards,