Beast tessellation shader is integrated into Unity's default Standard (for Built-in RP) and Lit (for Universal RP) shaders and offers exactly the same shader rendering features with additional tessellation effect:
Tessellation Types
Beast shaders offers four types of tessellation:
Adds fixed amount of tessellation to the whole mesh. This type of tessellation is useful for meshes with roughly the same size of faces on screen.
Models faces tessellation level is calculated based on their distance from the camera.
If mesh faces are not roughly the same sizes, then Fixed and Distance Based tessellation methods create effect when small faces are tessellated too much, while large triangles aren’t tessellated enough. One way to improve this is to compute tessellation levels based on triangle Edge Length on the screen.
This makes the shader a bit more expensive, but saves a lot of GPU work for parts of meshes that are outside of the Camera’s view.
Phong Tessellation modifies positions of the subdivided faces so that the resulting surface follows the mesh normals a bit. It’s quite an effective way of making low-poly meshes become more smooth.