How to allow particles to avoid mesh but pass along the surface of the 3d object?

[zyonneo]

Hi I created a trail of particles moving in straight line.I am hitting the particles on to a mesh.I have turned on the collision but I dont want to bounce of them also I dont want the particles to go inside mesh but float over the surface of the mesh.I have added an image of settings and what I want to achieve.Red line is what I want particle to move.It is like an airflow for car.

[richardkettlewell]

You might be able to use the Particle System Force Field component to fake this (Unity - Manual: Particle System Force Field)

But ultimately this aerodynamic effect is quite complicated, so would require implementing some kind of fluid simulation to solve properly, which Unity doesn’t offer out of the box. There might be asset store solutions (eg Fluvio) but they might have high performance costs for this kind of effect.

I think the best way to fake it would be to bake a Vector Field* in an external tool (eg Houdini) that simulates how the particles should travel around the car, then use that Vector Field inside Unity, either with the Particle System Force Field, or the new Visual Effect Graph (coming out of preview in 2019.3).

• a Vector Field is basically a 3D texture (think of it like a box) and every pixel inside the box tells particles that touch it, which direction to move in.

[zyonneo]

@richardkettlewell

You might be able to use the Particle System Force Field component to fake this (https://docs.unity3d.com/Manual/class-ParticleSystemForceField.html)

But ultimately this aerodynamic effect is quite complicated, so would require implementing some kind of fluid simulation to solve properly, which Unity doesn’t offer out of the box. There might be asset store solutions (eg Fluvio) but they might have high performance costs for this kind of effect.

I think the best way to fake it would be to bake a Vector Field* in an external tool (eg Houdini) that simulates how the particles should travel around the car, then use that Vector Field inside Unity, either with the Particle System Force Field, or the new Visual Effect Graph (coming out of preview in 2019.3).

• a Vector Field is basically a 3D texture (think of it like a box) and every pixel inside the box tells particles that touch it, which direction to move in.

Looking to deploy in AR mode Visual Effect Graph is for HDRP?

[richardkettlewell]

@zyonneo

Visual Effect Graph is for HDRP?

Correct

[zyonneo]

@richardkettlewell

You might be able to use the Particle System Force Field component to fake this (https://docs.unity3d.com/Manual/class-ParticleSystemForceField.html)

But ultimately this aerodynamic effect is quite complicated, so would require implementing some kind of fluid simulation to solve properly, which Unity doesn’t offer out of the box. There might be asset store solutions (eg Fluvio) but they might have high performance costs for this kind of effect.

I think the best way to fake it would be to bake a Vector Field* in an external tool (eg Houdini) that simulates how the particles should travel around the car, then use that Vector Field inside Unity, either with the Particle System Force Field, or the new Visual Effect Graph (coming out of preview in 2019.3).

• a Vector Field is basically a 3D texture (think of it like a box) and every pixel inside the box tells particles that touch it, which direction to move in.

https://www.youtube.com/watch?v=7k9wKFeX6qI

Something like this.But tutorial in Unreal …