Textures are loading twice in memory causing doubled CPU spike and memory usage about unitygltf

[pfcDorn]

Hey,
that is as intended. At line 505, it will only be created when the previous created texture has other sampler settings (like filterMode or WarpMode).
When they have both the same sampler settings, it's likely a bug.

[umeraamir-arthur]

Can we just change sampler settings of first one and assign it to the second one? As the first one (I suppose) has no use here after...

[pfcDorn]

So the first created Texture is not in use? Maybe you can share the file here?

[umeraamir-arthur]

It is the same case for any GLB it'll load the texture twice.... First one has only 1 reference which is (I guess) ImageCache list... and the second one is assigned to materials and has a proper use

[pfcDorn]

i will check! that's very likely a bug :)

[umeraamir-arthur]

It is a very old bug since first build which I once resolved as well but wasn't able to share at that time unfortunately.

Basically, the problem is that when you load any GLB from code using GLTFComponent in a build and then if you use memory profiler by Unity then it'll show that every texture is loaded 2 times. First texture has only 1 reference and the second has proper use of it. Also if you use CPU profiler then you can see big spikes when a texture is loaded because it once load a texture through LoadImage() and then Object.Instantiate() on same frame. Above mentioned places are the exact points which I found after profiling.

Hope these information help.

[pfcDorn]

Still needs some tests, but should prevent this behaviour now: 73f7b66

[umeraamir-arthur]

Hi @pfcDorn... Thankyou for sharing the implementation

I managed to brought back my implementation of the issue.

I would prefer older implementation because of many reasons

• If isFirstInstance is null then there might be issues to call Object.Instantiate(null) in that case
• isFirstInstance can't be null because of if (!source) return; at line 427
• No if-else needed for Object.Instantiate so it is a simpler version of it
• I've tested this on few test cases and was working fine on previous version

Here is the commit I made.

[pfcDorn]

With your solution you just removed completly the support for multiple sampler settings on a single texture. In Unity we need to duplicate a texture when we have in the gltf different sampler settings for the same texture.
Lets say we use Texture A in Material 1 and in Material 2. In Material 1 the texture will have WrapMode Repeat, and in Material 2 it will set to Clamp. So in this case we must dublicate the texture on import to support this. Otherwise one material will not be displayed correctly.

[umeraamir-arthur]

Yes but this statement is true for both of the above solutions I suppose.

The issue was that if you've 1 texture and 1 material it was still loading the texture twice.

[pfcDorn]

thats the reason why i added the isFirstInstance, so it only create the texture twice or more when it's needed (in case of multiple sampler states)

[umeraamir-arthur]

But I think isFirstInstance might always be true because of the lines on 429 and 430 ???

var source = _assetCache.ImageCache[sourceId];
if (!source) return;

Which means matchSamplerState on line 491 will always be false

[umeraamir-arthur]

@pfcDorn did you manage to find a work around?

[pfcDorn]

line 430 is only false (null) when the texture can't be created in line 427. So don't worry. Don't get confused with ImageCache and TextureCache here ;)

[umeraamir-arthur]

Oops! I was missing a point there... Thankyou