Core projection families in technical graphics From a high-level classification perspective, what are the two main types of projection used to represent 3D objects on 2D media?

Introduction / Context:
All graphical projections for representing 3D objects on 2D surfaces fall into two broad families. Recognizing these families helps students place specific methods (orthographic, isometric, oblique, perspective) in a coherent framework.

Given Data / Assumptions:

• Parallel projection uses parallel projectors; examples include orthographic multiview, isometric, dimetric, trimetric, and oblique.
• Perspective projection uses projectors that converge at a station point; examples include one-point, two-point, and three-point perspective.
• We seek the top-level categorization, not a specific sub-method.

Concept / Approach:
Choose the answer that names both top-level families explicitly. Orthographic is a subset of parallel projection, not a separate top-level family. “Convergent” is a descriptive term often used for perspective, but the standard naming pair is Perspective and Parallel.

Step-by-Step Solution:

Verification / Alternative check:
Graphics texts define orthographic as a type of parallel projection and perspective as the other major family.

Why Other Options Are Wrong:

• Parallel and Orthographic: Redundant because orthographic is a subset of parallel.
• Station-point and Perspective: Station point is a parameter of perspective, not a separate family.
• Parallel and Convergent: While descriptively close, the accepted term is Perspective, not merely Convergent.

Common Pitfalls:
Confusing isometric with perspective because both look 3D. Isometric is parallel; perspective shows size diminution with distance.

Final Answer:
Perspective and Parallel