Lighting & Rendering Flashcards

What is the purpose of tone mapping in the rendering pipeline?

Answer: To map high dynamic range (HDR) luminance values to the limited range of a display device while preserving visual detail

Tone mapping compresses HDR scene luminance values into the narrower range a monitor can display, preventing detail loss in very bright or very dark areas of the render.

In Blender, what is the key difference between the Cycles and EEVEE render engines?

Answer: Cycles is a physically accurate path tracer producing photorealistic results; EEVEE is a real-time rasterization engine trading accuracy for speed

Cycles uses physically based path tracing for accurate global illumination and reflections at the cost of longer render times, while EEVEE uses rasterization techniques for fast, interactive rendering.

What is a render farm and why is it used in professional 3D production?

Answer: A networked cluster of computers working together to distribute and accelerate the rendering of complex 3D frames

A render farm distributes individual frames or render tasks across many machines in parallel, dramatically reducing the total time required to render long animations or complex single frames.

What is screen-space ambient occlusion (SSAO) and what is its main limitation?

Answer: SSAO approximates ambient occlusion using only on-screen depth buffer data; its main limitation is that it cannot account for off-screen geometry

SSAO runs as a real-time screen-space post-process, meaning it can only consider geometry visible in the current frame and produces artifacts or misses occlusion from objects outside the viewport.

What is caustics in 3D rendering?

Answer: Concentrated light patterns formed when light refracts or reflects through transparent or reflective surfaces, such as the bright ripple patterns seen under water

Caustics are the focused light patterns produced when light bends through refractive materials like glass or water, creating bright, shifting patterns on surrounding surfaces.

What is the purpose of anti-aliasing in 3D rendering?

Answer: To smooth jagged, staircase-like edges along geometry boundaries by sampling multiple sub-pixel values and averaging the result

Anti-aliasing reduces the jagged 'staircase' artifact on diagonal and curved edges by sampling colors at sub-pixel positions and blending them, producing visually smooth silhouettes.

What is light baking in 3D workflows and when is it typically used?

Answer: Pre-computing lighting and shadow information from a scene and storing it as a static texture on a mesh, commonly used in real-time games to simulate complex lighting without runtime cost

Light baking pre-calculates expensive lighting calculations offline and stores them as lightmap textures, allowing real-time engines to display complex lighting without computing it every frame.