Help problem of particle position

Help problem of particle position - Printable Version

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+--- Thread: Help problem of particle position (/thread-2661.html)

problem of particle position - FZMv587 - 23-12-2020

Hi bro.
I make a rope and move it in runtime.
Now,i want to get some particles world position but i failed.

I use

Code:
actorIndex = rope.blueprint.groups[0].particleIndices[0]

to get actor index of this particle.

And i use

Code:
solverIndex = actor.solverIndices[actorIndex]

to get solver index of this particle

Finally,i use

Code:
position = actor.GetParticlePosition(solverIndex);

to get world position of this particle

Problem is this position is not change when i move rope, so i think maybe it is a local position.
Could you help me to get world position of particle?
Think you,waiting for you repose.

RE: problem of particle position - josemendez - 23-12-2020

Hi there,

Works fine for me, using the exact same code you posted:

Code:
using UnityEngine;

using Obi;

[RequireComponent(typeof(ObiActor))]

public class GetCPPosition : MonoBehaviour

{

    ObiActor actor;

    public int cpIndex = 0;

    void Start()

    {

        actor = GetComponent<ObiActor>();

    }

    private void OnValidate()

    {

        cpIndex = Mathf.Max(0, cpIndex);

    }

    void OnDrawGizmos()

    {

        if (actor != null &&

            actor.blueprint != null &&

            actor.blueprint.groups.Count > cpIndex &&

            actor.blueprint.groups[cpIndex].particleIndices.Count > 0)

        {

            int actorIndex = actor.blueprint.groups[cpIndex].particleIndices[0];

            int solverIndex = actor.solverIndices[actorIndex];

            Gizmos.DrawSphere(actor.GetParticlePosition(solverIndex), 0.5f);

        }

    }

}

RE: problem of particle position - FZMv587 - 23-12-2020

Hi，it ‘s me
Is the particle's world position are calculated by rope.gameObject.transform?
Because I use particleAttachment connect a particle group to the rope self, i move rope's position to move particles

set like this:

Code:
rope.GetComponents<ObiParticleAttachment>()[0].target = rope.gameObject.transform;

rope.GetComponents<ObiParticleAttachment>()[0].particleGroup = blueprint.groups[0];

move like this:

Code:
Vector3 to_new_position = new Vector3(0.0f, 0.0f, 1.0f);

rope.gameObject.transform.Translate(to_new_position, Space.World);

RE: problem of particle position - josemendez - 23-12-2020

(23-12-2020, 03:04 PM)FZMv587 Wrote: Hi，it ‘s me
Is the particle's world position are calculated by rope.gameObject.transform?
Because I use particleAttachment connect a particle group to the rope self, i move rope's position to move particles

set like this:

Code:
rope.GetComponents<ObiParticleAttachment>()[0].target = rope.gameObject.transform; rope.GetComponents<ObiParticleAttachment>()[0].particleGroup = blueprint.groups[0];
move like this:

Code:
Vector3 to_new_position = new Vector3(0.0f, 0.0f, 1.0f); rope.gameObject.transform.Translate(to_new_position, Space.World);

Particles are simulated in solver space. To convert to world-space, they're transformed using the solver's transform.

When you attach a particle to a target transform, the particle position at the time of setting the attachment's target/particleGroup is stored expressed in the target's local space. At runtime, this target-space position is converted to solver space and used to set the particle's position. Hope this makes sense!