Virtual Shadow Maps
High-resolution shadows in Unreal Engine 5
Also known as: VSM · UE5 Virtual Shadow Maps · Unreal shadow maps
Definition
Virtual Shadow Maps (VSM) are Unreal Engine 5's shadow technique, designed to work with Nanite and Lumen. Each light gets a very high-resolution virtual shadow map, but only the pages visible on screen are rendered and cached, which gives sharp, consistent shadows without hand-tuning cascade settings. They give film-like contact shadows on detailed geometry, at a cost that rises with scene complexity.
In production
In UE5 projects VSM is usually on by default, so artists notice it as crisp shadows on Nanite meshes. If you see shadow popping or slow frames, check the Virtual Shadow Map view mode and the cost in the GPU profiler. Meshes that move a lot, large masked foliage and assets with World Position Offset make shadow caching less effective and cost more, so keep animated geometry in check.
Tools that use Virtual Shadow Maps
See also
Lumen
UE5 dynamic global illumination
Nanite
UE5 virtualized geometry
World Position Offset
Move vertices from the material
Draw Call
GPU rendering command
Reflection Probe
Pre-captured cubemap for local reflections
Volumetric Lighting
Light scattered through a participating medium
Cascaded Shadow Maps
Shadows with more detail near the camera
Contact Shadows
Fine shadows where objects touch surfaces