Strip or unload built-in textures for headless server build

Hello everyone,

I'm currently experimenting with Unity as a dedicated game server. For each room I'm planning to spawn a new process, and I need to reduce memory footprint as much as possible.
However I can't seem to unload some built in textures, namely:
UnityNHxRoughness (32.3 KB)
UnityHalo (4.3 KB)
UnityAttenuation (2.3 KB)
UnityGrayscaleRamp (2.3 KB)
etc...



As you can see in the attached memory snapshot, almost 1/3 of the total memory are used up by built-in textures. My question, how to I reduce the memory footprint even more? How to strip these textures? What modules are using it?

I'm using Unity 2019.2.0f1, IL2CPP on Windows, disabled almost all built-in packages.

 

Well almost one week of trying out different methods I'm still stuck. However I have found out some useful things for others who may stumble into this problem.

After examining the build asset files, I found out that these textures are not packaged there during the build.

The only reference for the UnityNHxRoughness texture this is in

UnityStandardBRDF.cginc

shader include file

Code (CSharp):

1. half LUT_RANGE = 16.0; // must match range in NHxRoughness() function in GeneratedTextures.cpp

That means these textures are in fact generated when the player starts.

I have tried to forcefully destroy or unload the textures from memory with this

Code (CSharp):

1. var objs = Resources.FindObjectsOfTypeAll<Texture2D>();
2.         foreach (var obj in objs)
3.             Object.Destroy(obj);

But it does not work. For all built-in textures I'm getting this message

Destroying object "UnityNHxRoughness" is not allowed at this time.

So the most minimal memory I have managed to achieve is around 15MB with every Unity modules disabled. It would be great if someone from Unity would have a look at this, but in the mean time I think I submit a bug report.

 

You could ask the developer of the Headless Builder asset on the Asset Store if his/her asset includes stripping these textures. Often asset developers are more than happy to discuss how they have solved certain issues, even if you have no intention of making a purchase.

 

I really wouldn't worry about a little 32KB texture, given how large a minimal Unity project can be. That really sounds like premature/misdirected optimization?

Do you really need a process per 'room'? (and what is a room? - a group of players in a lobby/game, or a physical room in an MMO-ish game?). Can you run N of them on a single server instance?

 

The goal of this experiment is to see how feasible is to spawn one Unity instance for every room. What I meant with "room" is a short game session with 4 players. For example as in Diablo.

Probably the solution for such a problem is what you have just described. But I had to measure what is the absolute minimum memory consumption for a headless server.