Nanite, performance, LOD, and collision

Nanite Landscape boundary

Nanite can improve Landscape rendering performance, especially with Virtual Shadow Maps. It does not add source terrain detail or inherently improve image quality; the source data is identical.

UE 5.8 keeps both representations at runtime:

• Nanite Landscape data for Nanite rendering;
• non-Nanite Landscape data for systems including RVT, water, and other Landscape functions.

Therefore Nanite adds streaming and memory data. Measure the total system rather than assuming “Nanite replaces Landscape LOD.”

Workflow

1. Capture non-Nanite target performance and memory.
2. Enable Nanite on the Landscape.
3. Build Nanite data through the documented Landscape build/save path.
4. Confirm every proxy is up to date before comparing visuals or timing.
5. Inspect seams; enable Nanite Skirt and tune skirt depth only if needed.
6. If using Nanite tessellation/displacement, validate material settings, rebuilt data, shadows, collision mismatch, and scalability.
7. Compare GPU, CPU, memory, streaming, cook time, disk size, and edit iteration.

Landscape.Nanite.LiveRebuildOnModification is Experimental and live rebuild can significantly slow editing. Keep it off by default and perform controlled rebuilds. Epic's page also shows a differently ordered legacy spelling in prose; confirm the exact CVar through console help in the installed build before scripting it.

Landscape performance levers

• component and section count;
• visible component count and LOD distribution;
• material shader/texture cost and layer permutations;
• grass/foliage instance count, WPO, shadows, overdraw, culling;
• RVT page generation/uploads and pool memory;
• Nanite/VSM/tessellation cost;
• collision mip and physics queries;
• streaming and derived-data readiness.

Profile the dominant cost; do not apply every lever at once.

Collision mip

• Collision Mip Level controls complex/visibility collision detail.
• Simple Collision Mip Level controls simple/player collision detail.
• Higher mip values reduce geometry/memory but increase mismatch from rendered terrain.
• Epic notes that common cases keep Collision Mip at 0 and Simple Collision Mip at 1 or 2; validate against the actual movement/query requirements rather than adopting this blindly.
• Per-component overrides can reduce cost in inaccessible areas.

Render displacement/tessellation does not automatically redefine gameplay collision. Keep visible displacement within the acceptable collision error or provide another collision/gameplay solution.

Target capture

Record:

• stat unit, stat gpu, Insights trace, GPU profile;
• visible components/sections and draw calls;
• Landscape/material/GPU time;
• texture, RVT, Nanite, and total memory;
• streaming hitches at fastest traversal;
• collision query behavior and navigation rebuild/pathing;
• cold cook/load and warm traversal.