What are two types of shadows in Unity and how do you optimize them for performance?

• A. Hard shadows and soft shadows; optimize by reducing shadow distance, lowering shadow resolution, using cascaded shadow maps, and baking shadows where possible.
• B. Soft shadows only.
• C. Shadows do not impact performance.
• D. Shadows only exist in URP.

Answer: (A)

Shadows in Unity come in two practical forms: hard-edged shadows and soft-edged shadows. Hard shadows have crisp, defined edges and are generally cheaper to render because the edge calculation is straightforward. Soft shadows blur the edges to simulate penumbra, which looks more realistic but requires more sampling and filtering, so they cost more at runtime.

To optimize performance, you can tune several aspects that affect both types of shadows. Reducing shadow distance limits how far from the camera shadows are calculated, cutting unnecessary work for distant objects. Lowering shadow resolution decreases the texture detail of the shadow maps, saving GPU time while sacrificing some quality. Cascaded Shadow Maps improve quality where it matters most by using higher resolution for shadows that are closer to the camera and lower resolution for distant shadows, giving better visuals without a proportional performance hit. Baking shadows precomputes lighting for static scenes, so those shadows don’t need to be calculated in real time, which is ideal for performance-driven projects.

Shadows do impact performance, and they’re supported across Unity’s different rendering pipelines, not just URP, so it’s not accurate to treat them as pipeline-specific or non-impactful.