Virtual Texture
Stream only the visible tiles of a texture
Also known as: Virtual Texturing · VT · SVT · RVT · Streaming Virtual Texture · Runtime Virtual Texture
Definition
Virtual texturing splits a very large texture into small tiles and keeps only the tiles that are visible in memory, instead of loading whole mip chains. Unreal Engine has two systems: Streaming Virtual Texturing (SVT), where cooked texel data is loaded from disk, and Runtime Virtual Texturing (RVT), where the GPU generates texel data at runtime. SVT suits large artist-made textures and UDIM sets; RVT suits procedural or layered material output such as Landscape blending.
In production
Enable virtual texture support in the project settings, then mark individual textures as virtual in their asset settings. That lets a single 8K texture or a UDIM set live in a project with a smaller, steadier memory footprint. RVT is a common way to blend rocks and props into a Landscape: the terrain writes its color and height into an RVT and nearby meshes sample it. Virtual textures add sampling overhead, so keep ordinary small textures non-virtual.
Tools that use Virtual Texture
See also
Texture Streaming
Load only the mip you need
UDIM
Multi-tile UV layout
Mipmap
Pre-filtered texture down-sampling chain
Texel Density
Texture-to-surface ratio
Displacement Map
Actual geometry from a texture
Landscape Layers (Terrain Texturing)
Painting materials onto terrain
Landscape Texture Tiling Visible
Repeating patterns on terrain from a distance