metaballs/Assets/metaball/Scripts/MetaBall.cs

using UnityEngine;
using System.Collections;

namespace MetaBalls
{
    [ExecuteInEditMode]
    public class MetaBall : MonoBehaviour
    {
        public float radius = 0.09f;
        public bool negativeBall;

        [HideInInspector]
        public float factor = 1;
        Vector3 voidSize;

        public bool DrawGizmos;

        public virtual void OnDrawGizmos()
        {
            if (!DrawGizmos)
                return;

            if (voidSize != GetComponentInParent<Container>().transform.localScale)
            {
                voidSize = GetComponentInParent<Container>().transform.localScale;
            }

            Gizmos.color = Color.green;
            Gizmos.DrawWireSphere(transform.position, radius * Mathf.Min(voidSize.x, voidSize.y, voidSize.z));
        }

        public virtual void Start()
        {
            this.factor = (this.negativeBall ? -1 : 1) * this.radius * this.radius;
        }

        public virtual void Update()
        {
            this.factor = (this.negativeBall ? -1 : 1) * this.radius * this.radius;
        }
    }
}