using System.Collections;
using System.Collections.Generic;
using UnityEngine;

public class RandomInside : MonoBehaviour {
    public GameObject Prefab;
    public int NumberOfPrefabs = 50;
    public float Factor = 0.5f;

    void Start () {
        for (int i = 0; i <= NumberOfPrefabs; i++)
        {
        var obj = Instantiate(Prefab,GetRandomInsideTheMesh(),Quaternion.identity);
        obj.transform.parent = gameObject.transform;
        }
    }

public Vector3 GetRandomInsideTheMesh(){
    Mesh mesh = gameObject.GetComponent<MeshFilter>().mesh;
    Bounds bounds = mesh.bounds;
    var pos = transform.position;
    var scale = transform.localScale;
    float minX = pos.x - scale.x * bounds.size.x * Factor;
    float minY = pos.y - scale.y * bounds.size.y * Factor;
    float minZ = pos.z - scale.z * bounds.size.z * Factor;

    Vector3 RandomArea = new Vector3(Random.Range (minX, -minX),
                                 Random.Range (minY, -minY),
                                 Random.Range (minZ, -minZ));
    return RandomArea;
}
}