Need help getting a TAssetPtr asset loaded in game, getting crashes

[Nuchaz]

I’m working on a little card game project and this thing has like 550 cards for the most basic version and many more to add on top of that, so I decided I wanted to load my assets in C++ and expose them to blueprint as arrays where I can work them easily. I found and followed this tutorial the best I can (Asynchronous Asset Loading | Unreal Engine Documentation). I’m coming from a Java background and still learning C++ and that guide was a bit advanced for me, but I managed to kind of get what I wanted. I am able to search my card folder and create an array of TAssetPtr and expose them to blueprint. I can see on my blueprint, in the options, my 2 texture arrays are there and I can expand them and see all the textures as I would expect. Ok, so all good so far.I threw together a little loop in blueprint to spawn all the cards in an array so I could apply all the textures from the array as a good test to verify it works. I have a material instance setup and a texture sample set as a parameter and I can manually make an array in blueprint of textures and it seems to work fine. The chain that spawns the cards happens on game start, in the level blueprint I fire a custom event on the card table blueprint which spawns the test cards.

Heres a screenshot that shows the code, the blueprint, and and it running in game.

Next is where the problem comes in. When I plug in the texture sample from the array I built in code, the editor crashes with an unhandled exception. I am guessing it isn’t properly loaded or something, even though it does show up in the editor (just in the properties panel) and in blueprint. It doesn’t matter if I plug in the Array Element from the ForEachLoop into the Set Texture Parameter Value or if I plug in the little get index 0 of array node I have there, I still get the same crash. I tried plugging in an array get of index 0 in just to see if even one texture would work.

Heres a screenshot that shows the initial crash when I hit the simulate button if I have my UTexture2D array plugged in:

Heres a screenshot that shows just visual studio after I hit the Break button, it almost seems like whatever module is needed to show me a useful error isn’t loaded or something.

Also heres a code snippit of my declarations, maybe something needs to change here?

	UObjectLibrary* blackCardLibrary;
	UObjectLibrary* whiteCardLibrary;

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Cards)
	TArray<TAssetPtr<UTexture2D>> blackCards;

	UPROPERTY(VisibleAnywhere, BlueprintReadOnly, Category = Cards)
	TArray<TAssetPtr<UTexture2D>> whiteCards;

	UFUNCTION(BlueprintCallable, Category = CardLoading)
	void LoadCards();

I’ve been trying different things and googling around for answers, but I’m as a loss as to what to try next to get these textures loaded in game. It seems like they are working perfectly until I hit the play / simulate button and try to load them in game on a dynamic material instance.

How can I stop it from crashing? Am I approaching this correctly?, Is there something else I need to do when loading my assets?

Thanks.

[ScottSpadea]

causes problems, you should put a space between the angle brackets:

TArray<TAssetPtr<UTexture2D> >

[Nuchaz]

Thanks. I added the spaces and tried it and I got the same crash. I’ll keep that tip in mind though when I am doing the double angle brackets.

[ScottSpadea]

in the example, they check if (!ObjectLibrary) exists before creating the library and adding to root, so maybe this is happening multiple times?

maybe forget about loading 2 decks at once and just get 1 of them working first.

also since PDB files are mentioned in the error message, and they are a debugging thing, why not try compiling in Development Editor and seeing if you get the same crash.

https://docs.unrealengine.com/latest/INT/Programming/UnrealBuildSystem/Configuration/index.html
“If you encounter weird “RPC” or “PDB” link errors, then you should set bUseIncrementalLinking=false in ValidateConfiguration()”

or maybe arrays of TAssetPtr just don’t work with blueprint. maybe try accessing it in c++ instead…

[Nuchaz]

Thanks for the suggestions! First I tried the first few things in your suggestions. I added the if (!ObjectLibrary) check and commented out all of one deck of cards so I could concentrate one one. Visual studio was already set to Development mode so I tried some of the other mods and I checked the BuildConfiguration.xml file (I guess the documentation must be out of date, that mentions a .cs file) but I found the bUseIncrementalLinking boolean and it was already set to false. So after all that, still the same crash. So I went ahead with your last suggestion.

I tried to do it as simple as possible to figure if it would work and it does! It seems to work no problem. All I did was make a function to take the material instance I created in blueprint and the array index then just apply the texture from code using the arrays I already have setup and it seems to work.

I declared this:

UFUNCTION(BlueprintCallable, Category = CardLoading)

void setCardTextureParameter(int32 index, UMaterialInstanceDynamic* material);

then just added this super simple function:

void ACAHTable::setCardTextureParameter(int32 index, UMaterialInstanceDynamic* material)
{
	material->SetTextureParameterValue(TEXT("CardFace"), blackCards[index].Get());
}

Thanks, that is all I really need, I can totally work with this. I’ll probably migrate more of the stuff from blueprint to code, but yeah, I’m happy now.

[ScottSpadea]

sweet, im glad it works it seems that most blueprint problems can be fixed by switching to c++, especially anything dealing with arrays and structs.