Materials Count creates Memory Leak

Questions & Answers
1

Hello, I’ve noticed this issue and can’t figure out if this is due to my coding or unity bug. I change the material on the object a lot and my materials count increases and increases.

Here’s my sample code

if(renderer.material.name != Green.name + " (Instance)")
{
	renderer.material = Green;
}

this is in my update function.
This would happen every time I highlight it but it this seems to increase the count. Does anyone else had this problem, if so how did you solve it. Thank you

3

Note that unlike most other objects, Material instances are not automatically disposed when no gameObject/component is using them.

Anytime you create a material instance through script (which happens automatically whenever you use renderer.material instead of renderer.sharedMaterial), cache a reference to it, something like this:

_cachedMaterial = Instantiate(sourceMaterial) as Material;
renderer.sharedMaterial = _cachedMaterial;

If you later change to a different material or destroy the renderer, and won’t need _cachedMaterial again, manually dispose of the instance (since this instance was created through script, you won’t get a “Destroying assets is not permitted” error):

Destroy(_cachedMaterial);

(Use DestroyImmediate if this is an Editor script)

This will prevent material instances from leaking.

If you don’t need to change parameters on the material per-instance, use renderer.sharedMaterial instead - this will allow multiple objects to share one material reference, rather than instantiating a unique copy for each one.

2

  1. use Equals() to compare strings (sry java background)

  2. try

    renderer.materials = new Material[1];
    renderer.material[0] = Green;