Question by danik2003 · Oct 06, 2020 at 10:17 AM · c#unity 5 random

Why Random.Range with preset seed sometimes returns different values?

I have script, that pseudo randomly places buildings on the map, based on coordinates of the city.

         int tryes = 0;
         float rot_jumps = 90;
         
         Random.State init_state = Random.state;
         int x = 0;
         while((ex_small_cnt < ex_small || small_cnt < small || medium_cnt < medium || large_cnt < big || ex_large_cnt < ex_large) && tryes < 3000)
         {
             Random.seed = (int)((x * place.x * place.y) + place.x + place.y + x) + 11;
             if (medium_cnt < medium)
             {
                 GameObject house = Instantiate(medium_houses[Random.Range(0, medium_houses.Length)], houses_places[Random.Range(0, houses_places.Count)], Quaternion.Euler(0f, 0f, Random.Range(0, 8) * rot_jumps)) as GameObject;
                 house.transform.parent = wholeScene.transform;
                 if (house.GetComponent<HouseScript>().Collides()) Destroy(house);
                 else { medium_cnt++; buildings.Add(house); }
                 x++;
             }
             if(ex_small_cnt < ex_small)
             {
                 GameObject house = Instantiate(extra_small_houses[Random.Range(0, extra_small_houses.Length)], houses_places[Random.Range(0, houses_places.Count)], Quaternion.Euler(0f, 0f, Random.Range(0, 8)* rot_jumps)) as GameObject;
                 house.transform.parent = wholeScene.transform;
                 if(house.GetComponent<HouseScript>().Collides()) Destroy(house);
                 else {ex_small_cnt++; buildings.Add(house);}
                 x++;
             }
            if (small_cnt < small)
            {
                 GameObject house = Instantiate(small_houses[Random.Range(0, small_houses.Length)], houses_places[Random.Range(0, houses_places.Count)], Quaternion.Euler(0f, 0f, Random.Range(0, 8) * rot_jumps)) as GameObject;
                 house.transform.parent = wholeScene.transform;
                 if (house.GetComponent<HouseScript>().Collides()) Destroy(house);
                 else {small_cnt++; buildings.Add(house);}
                 x++;
            }
             if (large_cnt < big)
             {
                 GameObject house = Instantiate(large_houses[Random.Range(0, large_houses.Length)], houses_places[Random.Range(0, houses_places.Count)], Quaternion.Euler(0f, 0f, Random.Range(0, 8) * rot_jumps)) as GameObject;
                 house.transform.parent = wholeScene.transform;
                 if (house.GetComponent<HouseScript>().Collides()) Destroy(house);
                 else{ large_cnt++; buildings.Add(house); }
                 x++;
             }
             if (ex_large_cnt < ex_large)
             {
                 GameObject house = Instantiate(extra_large_houses[Random.Range(0, extra_large_houses.Length)], houses_places[Random.Range(0, houses_places.Count)], Quaternion.Euler(0f, 0f, Random.Range(0, 8) * rot_jumps)) as GameObject;
                 house.transform.parent = wholeScene.transform;
                 if (house.GetComponent<HouseScript>().Collides()) Destroy(house);
                 else {ex_large_cnt++; buildings.Add(house); }
                 x++;
             }
             tryes++;
         }
         Random.state = init_state;

Everything works perfect, but only for some amount of times I run a game. After(let's say 20) times I play a game, all houses' displacement spontaneously changes and remains same for 20 more plays and than changes once more... I've already checked Random.seed and it remains same. I also know, that Random.Range affects Random.Range, but it's not a problem in my case.

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