Get all meshes in an area... without colliders.

So I have a script that, whenever it is instantiated, needs to grab all meshes within its object's bounds and iterate over all of them.

Originally I used:

Code (csharp):

1. Collider[] colliders = Physics.OverlapSphere(transform.position, _myRadius);
2. for (int i = 0; i < colliders.Length; i++)
3. {
4.     MeshFilter filter = colliders[i].GetComponent<MeshFilter>();
5.     if(filter != null)
6.     {
7.         //Do Stuff.
8.     }
9. }

Which was happy and fast but required that every object had to have a collider on it. Turns out this wasn't possible so I had to switch to:

Code (csharp):

1. MeshFilter[] filters = FindObjectsOfType<MeshFilter>();
2. for (int i = 0; i < filters.Length; i++)
3. {
4.     MeshFilter filter = filters[i];
5.    
6.     if (filter.renderer.bounds.Intersects(_myBounds))
7.     {
8.         //Do Stuff
9.     }
10. }

This, as you might imagine, is not so fast. With the sheer number of objects in our scenes, it's actually unacceptably slow.

So my question, has anyone found any fast ways of gathering all meshes within an area that does not require colliders?

 

The only way I know how to do that is to go through all of the gameobjects in the scene and calculate the distance from the object. Doubt that is faster though.

" Which was happy and fast but required that every object had to have a collider on it. Turns out this wasn't possible so I had to switch to: "

Why wasnt this possible?

 

Just the way the artists had set up their levels. I came in on the project when it was part way done and going back and changing how collision was done on every object wasn't really an option

 

You couldn't use trigger colliders on their own layer?

 

The reason I use the MeshFilters is I need to do a bounds check to see if a mesh intersects the bounds of my object. Distance wouldn't work because that's just from the center and there is a wide variance of mesh sizes in the scene.

 

Thats acctually what physics is for, to detect exactly that stuff.
Iterating over all objects is never a good idea, nor good design, no matter what you acctually do with it. Therefore, either add a box collider as bounding box or implement your own logic.

As of implementing your own logic, you'll have to dive into the game physics world. Create a custom component representing a bounding box and check them via a broadphase algorythm, either Hierarchical hash grid or Sweep and Prune.

 

Why is it not possible to have a collider on everything? If you have some which should not collide, set their layer to one which is ignored in the Physics settings

 

if you have a bounds, and you iterate through all the active objects in the scene, you can then figure if each object has a meshfilter. If it does, compare the meshfilter's bounds to the bounds you are looking at. That would be the "correct" way to do it.

Bounds to bounds testing is very fast, faster than Vector3.Distance.

 

That's actually what I'm doing. There are a LOT of objects in our scenes however, so its a bit slower than I'd prefer.

 

could have empty objects with a trigger and a list of all objects within that trigger... when your player enters each trigger area it only has to check vs that area's list of objects

 

hmmm, that's an interesting idea. Could do a pre-bake like the Occlusion bake.