(No anwers? :( )How to spawn Random Pedestrians in a raduis?

Check out Instantiate and Random.Range from documentary

Hi,

This question can be broken up into different steps. All within a modified for loop:

 for (int i = 0; i < NumberOfSpawns; i = i) { /* Code Below Goes In Here*/ }

Note that we are not doing i++. Because we want to manually increase the count if we had a successful spawn.

Within the for loop we need a few steps:

Step 1: The first is to find a random spawning position.

This can be done with the Random.Range() function mentioned above. Use the following Code:

 // Get position of Circle
     float circleParam = 2 * Mathf.PI * Random.Range (0.0f, 1.0f );
     // Select Start Position
     Vector3 startPos = new Vector3 (
                      radius * Mathf.Sin (circleParam),
                      0.5f, /* Spawn above ground */
                      radius * Mathf.Cos (circleParam )
      );
 

Step 2: Check for Collision

In this step use SpherecastAll to check for collision. below is a written function that checks for collision within a certain radius.

 // Inside for loop:
 bool canSpawn = !isCollision (prefabRadius, startPos);
 
 
 // The function
 bool isCollision (radius, position) {
       // Create new ray
       Ray ray = new Ray(position, Vector3.up);
 
      // Create Raycast hits array
       RaycastHit[] hits;
        
       // Do the raycast
       hits = Physics.SphereCastAll(ray, radius, 0f); //Can change 0f to prefabHeight / 2.1f if you need to check height
 
 return hits.length > 0;
 }

Step 3: Spawn or continue to next step

No that we know if it will collide with an object or not we can write the end of the for loop here:

 if (canSpawn) { // you can spawn it so do it
     // Instantiate the object
    GameObject obj = Instantiate (prefab, startPosition, Quaternion.identity * Quaternion.Euler (new Vector3(0, Range.Random(0, 359), 0))) as GameObject;
 
   // IMPORTANT: Increase the loop counter or you will get stuck in the loop
 i++;
 } else 
     continue; // Step to the next iteration without increasing i

All of this will ensure that you spawn the selected amount of objects and that they do not collide.

FINALLY: If you want them to despawn when out of range then keep track off all the objects in a list and use this function below in the LateUpdate function:

 void LateUpdate () {
    for (int i = 0; i < enemyList.Count; i = i) {
   // Get the distance between them
    float distanceFromPlayer = Vector3.Distance (playerPosition, enemyList[i].transform.position);
   
    // Remove if greater than radius
    if (distanceFromPlayer > radius) {
       // remove from list
       enemyList.Remove (enemyList[i]); 
    } else {
    // No Object Removed so increase i 
   i++;
   }
   }
 }