Question Unity UI Memory Allocation from Sprites

Hello. I have a pretty simple scene set up: there is a Unity UI Canvas that has multiple children with Image components. It's designed so that when I hit a button, all the Images will choose new sprites from an image manager. The image manager has a list of Scriptable objects called Displays that each have references to some number of sprites.

When profiling, I can see that after each generation my Texture memory continues to go up. At any time, there are only a small handful of images visible. If I run this enough, Unity crashes trying to allocate memory with 16 alignment.

How can I use script to manually clear out my texture memory?

Ive tried both

Code (CSharp):

1. System.GC.Collect();
2. Resources.UnloadUnusedAssets();

with no luck.
Looking for advice. Thank you.

 

Are you new-ing anything up, or creating sprites or creating textures?

If so you generally gotta Destroy() Unity things, and obviously not hang onto references to them.

Years ago I grabbed an FPS script off somewhere on the interwebs and because I was a nub I failed to notice that it had a

style = new GUIStyle()

call right within OnGUI() so it eventually leaked and blew.

 

Nah. I have a non-monobehavior that has a new one created every generation. But it's stored in a single variable that I would assume Garbage Collection handles. When I use the profiler, it really is all the PNG images taking up texture memory.

 

Well the thing is, while your C# class gets GC'd, any references to Unity objects in it won't. Remember: Unity objects are just wrappers around C++ objects, and to the GC, those objects do not exist at all (i.e. unmanaged)

So you must have a Destroy() method in your class (or make your class implements the standard C# IDisposable interface) that takes care of destroying all Unity objects, which gets called when the class is no longer needed.

 

Thanks for the feedback, guys. I actually refactored my code. The image shows the system I had before, and, after drawing it out, it became obvious why things werent getting released from memory, even tho it seems like the sprite references COULD have been removed.

I have moved all my high res imagery into Resources folders, and what I have now is a list of names that will Resources.Load<T>() them for as long as i need and then Resources.UnloadUnusedAssets() when I dont need them again.