# Unity - Proper use of threads with procedural generation

I have been working on a simple chunk based terrain generation system, with voxel octrees. The overall method works pretty well, but testing this system with large amounts of chunks completely freezes the game/main thread until the generation process is finished. Looking for a solution, I read about threads and coroutines and I implemented a simple thread class (based on this template) to call the "generate" function from it. The only advantage I had was a faster generation, with full CPU usage, but the game still freezes until the chunks are completely loaded. Am I doing something wrong? Here some parts of the code:

public class ChunkThread : ThreadedJob {
public Chunk chunk;
chunk.root = chunk.root.BuildOctree (chunk.pos, Chunk.size, -1);
}
protected override void OnFinished(){
chunk.RenderChunk ();
}
}


This is the simple Thread class I use to call the Build function, and the Render function when finished. This piece of code below is the start\update method for every Chunk gameObject (I kept only the relevant part), that simply creates the Thread instance and calls Start() pressing the mouse button.

void Start () {
t.chunk = this;
}
void Update () {
if (Input.GetButtonDown ("Fire1")) {
t.Start ();
}


Now, coming to the questions, what should I do to generate the terrain while still being able to play? Is there something wrong in my thread? Should I use a thread pool, if so how?

• Whats this ThreadedJob class ? Not part of unity as far as I am aware .. you'll need to write some sort of threading code to pass the work off to another thread. – War Mar 14 '15 at 13:17
• nvm ... just noticed the link to the code for it ... I took a similar approach to this. – War Mar 14 '15 at 13:23

I took a similar approach here:

My code basically does what the .Net 4 tasks stuff does (well some of it) in that I pass a lambda in and get a task back ....

var task = Task.Factory.StartNew(() => { return GenerateLotsOfData(); });


I then use update to handle when the task is complete ...

void update() {