How does the "Import Buffer as Texture 2D" node work?

[The_untextured]

The title explains it. This is the node:

I can’t figure out how it works. I am using it to try and save and load a render target, but I just don’t know how this node works. As in: how do I structure the input buffer array?

Having used other rendering APIs in the past, such as SFML, I assumed it was RGBA RGBA RGBA… for as many pixels as there are, but apparently that just gives out an empty image. (invalid object reference)

[nande]

i think the buffer is a byte array for what is " file like" data.
in other words similar to a binary jpeg.

check the comment on " compress image" and " decompress image" https://github.com/EpicGames/UnrealEngine/blob/a3cb3d8fdec1fc32f071ae7d22250f33f80b21c4/Engine/Source/Runtime/Engine/Public/ImageUtils.h#L130

i dont see an export equivalent for the import buffer as texture 2d
i think you might get more luck using “ExportTexture2D” and " ImportFileAsTexture2D" (both manipulates a file directly and uses a filename).

[The_untextured]

The problem with using a file is that I would like to have all save data in one single file. I will have a look at the source code, otherwise, I have a slower, alternative method… But it’s quite slow…

[The_untextured]

Solved. What I am trying to do is save a render target to a save file and load it back in. The render target uses 8 bit RGB (24 bits per pixel) and will always be square. To save, I just use the “Read Render Target” node: it’s slow but it works. I save the output using a SaveGame object.

To load it back in, I created a C++ function which looks as follows:
.h:

[...]	UFUNCTION(BlueprintCallable, Category = "Rendering")	static TArray<uint8> getBufferFromColorArray(TArray<FColor> arr); [...] 

.cpp:

#define add(num) working.Add(num) #define addInt(num, size) working.Append(intToBytes(num, size)) TArray<uint8> UCPP_BPFuncLib::getBufferFromColorArray(TArray<FColor> arr) {	int size = sqrt(arr.Num());	TArray<uint8> working;	//header	add(66);	add(77);	//size	add(0);	add(0);	add(0);	add(0);	//app info	add(0);	add(0);	add(0);	add(0);	//start address	add(54);	add(0);	add(0);	add(0);	//BITMAPINFOHEADER	//size of header	add(40);	add(0);	add(0);	add(0);	//image size	addInt(size, 4);	addInt(size, 4);	//color planes	addInt(1, 2);	//color depth	addInt(24, 2);	//compression	addInt(0, 4);	//dummy int	addInt(0, 4);	//resolution	addInt(0, 4);	addInt(0, 4);	//colors in color pallette	addInt(0, 4);	//important colors	addInt(0, 4);	//image buffer	size = arr.Num();	for (int i = 0; i < size; i++) {	add(arr[i].B);	add(arr[i].G);	add(arr[i].R);	}	//set real file size	size = working.Num();	auto tmp = intToBytes(size, size);	for (int i = 0; i < 4; i++) {	working[i + 2] = tmp[i];	}	return working; } 

This pretty much just turns the FColor buffer saved into a uint8 (byte) buffer array which can be used in the “Import Buffer as Texture 2D” node.

I then use this image as a parameter of a UI material (“Tex”) as such:

(The reason why the V component in the texture coordinate is flipped is due to how bitmaps are saved. Otherwise the image gets flipped.)
I then copy the material to the render target and it’s done!