Method to use very large textures:

Divide and win, Take care that the texture you use if it is larger than > 8192 cuts it into 4 square segments and multiples of 2. So on, you can deal with the size you want.

Then instead of instantiating 1 drawing object, instances 4 and organize them so that they stay together and ordered, and assign each one a different texture but in reality it is the 4 that you generated when making the cut.

Example

textureGrand_00 - > TopLeft instance

texturaGrande_01 - > TopRight instance

texturaGrande_02 - > BottomLeft instance

texturaGrande_03 - > BottomRight instance

Method to use only one segment

What you are looking for here is to use an area of your huge image, the strategy to follow is that you create a textured object, but reading only the corresponding bound (region).

In such a way having an example matrix: 10x10 We want only an area of 4x4, we read the bits of the giant image whose (center + half of our rago - left side) is where it starts, imagining that it is the center 5 - (4/2) = row 3, 5 - (4/2) = col 3 we start reading in 3x3 up to 3 + bound and 3 + bound bone 7x7 and that small matrix will make up our new image.

Now we simply command a swap to the visualization object that uses our new texture.

To edit it

Simply, edit the small matrix at your whim and then overwrite the region of the giant's buffer (original) to the buffer or file, as needed. The rest is to repeat the process each time you move the image.