Deepen your understanding of lighting and shading with this focused 3D games quiz. Challenge your knowledge of essential techniques, terminology, and in-game visual effects for modern 3D game environments.
Which type of light simulates sunlight by emitting parallel rays in 3D game environments?
Explanation: Directional light is designed to mimic sunlight by emitting parallel light rays, making it perfect for outdoor scenes. Point lights emit light in all directions from a single source, not producing parallel rays. Ambient light is a non-directional, diffuse light that illuminates the entire scene evenly, lacking directionality. Spot lights emit a cone-shaped beam that is focused in a specific direction but does not simulate sunlight.
Which shading model produces the smoothest transitions across the surface of a 3D object by averaging vertex normals, often used to make curved surfaces appear more realistic?
Explanation: Phong shading interpolates normals across the surface and calculates lighting per pixel, resulting in smooth shading and realistic highlights. Gouraud shading averages normals at vertices but computes lighting per vertex, which can miss small specular highlights. Flat shading applies one normal and color per face, creating a faceted look. Lambert shading models diffuse reflection but does not focus on smooth transitions from vertex to vertex.
What is the main benefit of baking lighting into textures for static game environments?
Explanation: Baking lighting precomputes illumination and embeds it into textures, freeing up processing power by avoiding real-time calculations for static elements. Improved dynamic shadow accuracy and interactive reflections require dynamic, not baked, calculations. Real-time color changes on objects would be limited, because baked lighting is static and does not update with gameplay or lighting changes.
In shadow mapping, what is the primary reason for shadow artifacts such as jagged or 'pixelated' edges, often referred to as 'shadow aliasing'?
Explanation: Low shadow map resolution means there are not enough pixels to accurately represent edges, resulting in jagged shadows—a problem called aliasing. Incorrect normal mapping affects surface shading, not shadow edge quality. Overuse of specular highlights would make surfaces appear too shiny but not affect shadow sharpness. Excessive ambient occlusion causes darkening in crevices but does not create jagged shadow edges.
Why is ambient occlusion often added to 3D game scenes, especially in corners and under objects?
Explanation: Ambient occlusion darkens creases, corners, and areas where light is less likely to reach, creating a sense of depth and spatial realism. It does not create uniform lighting; that is the purpose of ambient light. Ambient occlusion does not directly impact water reflections or make reflective surfaces brighter, but rather enhances dimensionality through shadow detail.