In 2022, researchers rediscovered ancient indigenous glyphs, or drawings, on the walls of a cave in Alabama. The cave's ceiling was only a few feet high, affording no position from which the glyphs, being as wide as ten feet, could be viewed or photographed in their entirety. However, the researchers used a technique called photogrammetry to assemble numerous photos of the walls into a 3D model. They then worked with representatives of tribes originally from the region, including the Chickasaw Nation, to understand the significance of the animal and humanoid figures adorning the cave.

According to the text, what challenge did the researchers have to overcome to examine the glyphs?