Why are bitmaps useful for displaying images but less useful for three-dimensional calculations?

Bitmaps are highly effective for displaying images because they represent a display space as a grid of pixels, allowing for the precise storage and rendering of continuous-tone images, such as photographs, with a wide range of colors and subtle gradations.1

However, bitmaps are less useful for three-dimensional calculations because they lack the necessary structural information to model objects in 3D space. Computational tasks in 3D graphics require a representation of the objects themselves—often defined by polygons or mathematical curves like Bezier curves—rather than just the final color values of a 2D grid.2

To achieve realism in 3D, systems must perform complex operations such as:
* Transformations: Calculating how objects move or rotate relative to the observer.2
* Hidden Surface Elimination: Determining which surfaces are visible and which are obscured by others, often by calculating the "depth" of each pixel.2
* Lighting and Shading: Modeling the interaction of light with surfaces using techniques like ray tracing or radiosity, which require geometric data rather than static pixel values.2

Because bitmaps only store the final output of these calculations, they cannot be easily manipulated to simulate these dynamic 3D interactions.2