Does anyone know how to use UTexture2D::UpdateTextureRegions()?

The function can be found here:

UTexture2D::UpdateTextureRegions | Unreal Engine Documentation

And it’s really annoying because the Wiki is just…wrong.

If you look you can see the function takes a template function as it’s final argument but when you scroll down you’ll see it lists the old final argument as a boolean.

This post shows how to use the function:

UpdateTextureRegions Pitch - Rendering - Epic Developer Community Forums

But the problem I’m having is I can’t figure out how to implement the DataCleanUpFunc in a class and I can’t seem to find any examples.

So maybe this is a more of a generic C++ question but how do I declare a Template function as a member function?

The wiki is beyond frustrating. I really wish they’d add an example on how to use things.

Any help will be greatly appreciated!

Looks like the interface of UpdateTextureRegions changed, but those note haven’t updated yet.

DataCleanupFunc have its own default implement, which means do nothing:


TFunction<void(uint8* SrcData, const FUpdateTextureRegion2D* Regions)> DataCleanupFunc = ](uint8*, const FUpdateTextureRegion2D*){}

DataCleanupFunc like below would be similar to bFreeData is true, any variables in DataCleanupFunc has to be thread safe:


TFunction<void(uint8*, const FUpdateTextureRegion2D*)> DataCleanupFunc = [this](uint8* InTextureData, const FUpdateTextureRegion2D* InRegions)
            {
                delete InTextureData; 
                delete InRegions; 
            };

I’ve spent the last 45 minutes trying to figure out how it works. Finally…

.H



static TFunction<void(uint8* SrcData, const FUpdateTextureRegion2D* Regions)> CleanMemory(uint8* srcData, const FUpdateTextureRegion2D* regions);


.CPP



TFunction<void(uint8* SrcData, const FUpdateTextureRegion2D* Regions)> UMyClass::CleanMemory(uint8* srcData, const FUpdateTextureRegion2D* regions)
{
  delete srcData;
  delete regions;
  return 0;
}


Usage



destTexture->UpdateTextureRegions(0, 1, updateTextureRegion, BufferPitch, BytesPerPixel, newTextureBuffer, &CleanMemory);


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