可以在上述你给我的代码中不设置particles.particleNoiseTex和particles.particleSpriteTex吗

当然可以。如果你不设置这两个参数，系统会使用默认的噪声纹理和粒子纹理。以下是修改后的代码示例：

using UnityEngine;

public class ParticleController : MonoBehaviour
{
    public int numParticles = 10000;
    public float maxDistance = 5f;
    public float particleSize = 0.1f;
    public float particleSpeed = 0.1f;

    private ParticleSystem particles;

    void Start()
    {
        particles = GetComponent<ParticleSystem>();

        var main = particles.main;
        main.startSpeed = 0f;
        main.startSize = particleSize;

        var emission = particles.emission;
        emission.rateOverTime = numParticles / 5f;

        var shape = particles.shape;
        shape.shapeType = ParticleSystemShapeType.Sphere;
        shape.radius = maxDistance;

        var velocity = particles.velocityOverLifetime;
        velocity.enabled = true;
        velocity.space = ParticleSystemSimulationSpace.World;
        velocity.x = new ParticleSystem.MinMaxCurve(-particleSpeed, particleSpeed);
        velocity.y = new ParticleSystem.MinMaxCurve(-particleSpeed, particleSpeed);
        velocity.z = new ParticleSystem.MinMaxCurve(-particleSpeed, particleSpeed);
    }
}

这段代码会使用默认的噪声纹理和粒子纹理，不会造成任何问题。