Final answer:
Paintings on cave walls are considered 2D art because they present flat, two-dimensional representations, regardless of the wall's texture or any illusion of depth created. These artworks do not extend into three dimensions but remain on the surface, using pigments and techniques that enhance the visual impression without making the images physically 3D.
Step-by-step explanation:
Despite the texture of cave walls, paintings on them are considered 2D art because they essentially consist of two-dimensional representations. These paintings do not occupy physical space in three dimensions; instead, they display a flattened image on the surface of the cave walls. Although artists sometimes utilized the natural contours of the cave walls to enhance the effect of their art, creating a sort of pseudo-3D effect, the art itself remains two-dimensional, as it does not project outward or have a form that can be viewed from multiple angles.
The application of pigments like charcoal and ochre, as well as the utilization of scraping techniques to prepare surfaces, allowed these early artists to leave their mark in a manner that persisted through the ages. In places like the Chauvet Cave, the use of complex scenes displaying interaction between animals, and taking advantage of the wall textures, shows a sophisticated approach to creating a dynamic illusion of depth and movement, yet the depictions remain on the flat two-dimension plane of the wall.
In conclusion, despite the inherent bumps and irregularities of the rock surfaces, cave paintings do not exhibit the physical dimensions necessary to be considered 3D art. The visual impressions of depth, interaction, and textures are artistic techniques to enhance the 2D imagery, not to transform it into a three-dimensional artwork.