A Runtime Virtual Texture (RVT) creates its texel data on demand using the GPU at runtime, and works similarly to traditional texture mapping. The RVT caches shading data over large areas, making them a good fit for Landscape shading that uses decal-like materials and splines that are well suited to conform to the terrain.
Using RVT will allow asset and landscape texture blend with each other seamlessly without any harsh lines and allows better improved performance when using high resolution textures. Also able to add height information to a landscape material without additional performance hit.
The first part is to enable virtual textures in the project setting to be able use RVT.
Search for RVTV and drag in two volume in the scene
Assign the materials to the RVT volume and then set the bound of the landscape.
Assign the materials to the landscape
Created a function material to handle the virtual textures