Why Unity freezes while creating Meshes procedurally?

[Wdarkfenix]

I’m creating a mesh procedurally with around 10000 vertices, the problem is that when I start the mesh generation it freezes for a few moments, I used the time method to get the number of frames that past but it appears that not a single one past, then the mesh is finished, but I dont want that the program freeze each time that I generate a new mesh, 'cause I’m doing it constantly.

The arrays fills automatically before creating the mesh, but just filling them without sending them to the mesh there’s no lag, so I don’t think the problem is there.

Also, if ,after generating the mesh, a method move all the vertices around there’s no lag, so the manipulation of the mesh appears to be ok too, anyone has a clue of why is this happening?.

Here’s the codo so you can take a look:

	public void Build(	GameObject GObject,
						List<Vector3>	chunkPosition,
						List<Vector3>	chunkRotation,
						List<int>		chunkSides,
						List<int>		chunkSpace){
		float time1,time2,timeResult;
		time1 = Time.time;    		
		int	arraySize	  = 0,
			index		  =	0,
			sidesToRender = 0,
			tama		  =	chunkBlockID.Count;
		
		MeshFilter	meshFilter	= GObject.GetComponent<MeshFilter>();
		Mesh 		mesh		= meshFilter.mesh;

		mesh.Clear();
		
	//Each position in each list represents information of a cube that occupies that place
	//chunkSpace represent the number of triangles of the cube that are to be rendered

		for (int i = 0; i < tama; i++)
			arraySize += chunkSpace*;*

•  Vector3[] vertices = new Vector3[arraySize];*
  

•  Vector2[] uv       = new Vector2[arraySize];*
  

•  int[] triangles    = new int[arraySize];*
  

•  Vector3 Temp       = new Vector3(0,0,0);*
  

•  ////ChunkSides contains six glags, one per side, so this cycle decides the orientation of each triangle*
  

•  for (int i = 0; i < tama; i++){//Todos los posibles bloques*
  

_ sidesToRender = chunkSides*;_
_ for(int j = 0,selector = 1,Kstart = 0,Kend = 6;_
_ j < 6;_
_ j++ ,selector = 2,Kstart += 6,Kend += 6){_
_ //If the flag of a side is on, then add the respective rendering parts_
* if((sidesToRender&selector) != 0)*
* for(int k = Kstart; k < Kend; k++, index++){*
* vertices[index] = Shapes.CubeVx[k]+Temp;*
* triangles[index]= index;*
* uv[index] = Shapes.CubeUV[k];*
* }*
* }*
* }*
* mesh.vertices = vertices;*
* mesh.triangles = triangles;*

* mesh.uv = uv;*
* mesh.RecalculateNormals();*
* mesh.RecalculateBounds();*
* mesh.Optimize();*
* time2 = Time.time;*
* timeResult = time2-time1;*
* print(timeResult);*
//Get the total time elapsed (it always gives me 0)
* }*

[whydoidoit]

Firstly no frames will pass if you are taking a long time to do something, it will be a synchronous operation.

If you want to know how long individual parts take you could use a StopWatch to time them.

Without seeing your code it’s hard to tell why its taking some time, but of course creating a mesh will potentially need to do lots of things with the GPU and allocate a significant number of objects. One solution would be to prepare a collection of meshes and then manipulate them as that seems to be a fast enough operation for you.