What defines the appearance of a 3D object in Unity?

The appearance of a 3D object in Unity is primarily defined by its material. A material in Unity is a combination of textures, shaders, and other properties that determine how the object interacts with light and how its surface looks visually.

When you apply a material to a 3D model, you can control various attributes, such as color, shininess, and transparency, as well as how textures are mapped onto the surface. The material is essentially the curated collection of settings that harmonize textures and shaders for the desired visual effect on the object in the game.

While textures provide the visual detail and images on the surface of the 3D object, and shaders define how to render the surface in relation to lighting and viewing angles, it is the material that encompasses and integrates these elements, thereby shaping the object's overall appearance within the scene. The mesh, on the other hand, refers to the geometric structure of the object itself, which does not inherently define its visual aspect without a material applied to it.