Still doesn't work
In the meantime I swapped the rectangle shape for vertices because memory allocation started to become problematic, but even with vertices I can't draw them into render texture, while still using the noise texture
EDIT:
I've just wrote a simple program that sets texture to a rectangle and then draws it into render texture, the render texture is then set to another rectangle, which is then drawn into the render window, and the result is a white rectangle, so I assume that the render texture only saves the shape and its color, not its texture :/ Is it intended ?