Perceptual realism in 3D focuses on creating the illusion of reality as perceived by humans, while physical accuracy refers to strict conformity to real-world physical laws and measurements.
Perceptual realism uses visual cues like lighting, texture, and composition to make a model "look real" to the eye, often simplifying details such as exact physics or dimensions. Physical accuracy, by contrast, ensures the model precisely matches real-world properties like size, mass, or material behavior, which is critical for functional or scientific applications.
In practice, prioritize based on goals: entertainment or visualization may lean on perceptual realism, while engineering simulations or product design typically require physical accuracy.