What is the maximum number of objects that can be represented using the…

Concept

A Z-buffer is a screen-space visibility structure: it stores one depth value for each pixel, not one record for each object in the scene.

Whenever rasterization produces a fragment at a pixel, the fragment depth is compared with the stored depth; the nearer fragment updates the depth and color values.

Application

1. Suppose three objects overlap at one pixel. Rasterize the first object and store its fragment depth.

2. Rasterize the second object, compare its fragment depth with the stored value, and retain the nearer depth.

3. Rasterize the third object and perform the same comparison again. Additional objects repeat exactly this operation without adding an object-count field to the buffer.

Contrast

• Only one object confuses one stored depth sample per pixel with one object in the scene.

• Only two objects confuses a two-value depth comparison with a two-object capacity.

• Arbitrary number of objects processed one at a time reflects the repeated rasterization and depth-testing process.

• Cannot represent any object confuses the absence of stored geometry in the depth buffer with an inability to determine visible object surfaces.

Result

Therefore, the Z-buffer algorithm can process an arbitrary number of objects, one at a time; practical limits come from rendering resources, not from a fixed object count in the algorithm.