Hello. Thanks for the answer, the shadows without tessellation were really corrected, but as soon as I turn on the tessellation, they break again. Here is an example of a modified shader: addPass shader is the same as firstPass (tessellation). Texture Checkers from ASE examples. In both shaders, the Cast Shadows option is enabled. Forward rendering: Deferred rendering: It seems that forward rendering does not take into account terrain tessellation when shading, and deferred rendering does this with errors. Also, the problem with cutting off polygons that are not visible without Vertex Offset, but with it they should be displayed, remains.