Description: The vertex normal is a vector that represents the direction perpendicular to the surface of a vertex in a 3D model. This vector is fundamental in computer graphics, as it is used to determine how light interacts with the surfaces of objects. In more technical terms, the normal of a vertex is calculated from the vectors defining the adjacent faces, allowing for an accurate representation of the object’s geometry. The length of the normal vector is usually unitary, meaning its magnitude is equal to one, thus facilitating its use in lighting and shading calculations. Normals are essential for techniques such as Phong shading and normal mapping, which enhance the visual appearance of 3D models by simulating how light reflects off surfaces. In graphics programming environments, normals are specified alongside vertex coordinates and are used in the fragment processing stage to calculate the final color of each pixel based on lighting. The correct definition and use of vertex normals are crucial for achieving realistic and efficient rendering in graphics applications, video games, and 3D simulations.
