This information is straight from the Nexus description:
Tes4ll creates new and individual high-resolution landscape meshes including all the additional changes added by the mods which one has installed.
To use this tool, one has different choices:
A one-click method on one of the prepared windows bat-file, if you would like to use a GUI, please download my MPGUI in addition, or download one of the pregenerated meshes
In addition to that, it has an expert modus where a script allows to configure the behavior of vertex setting and calculation completely, up to the placement of single vertices. If you interested, read the full manual.
Good to know...
Before installing the new meshes, make a backup of datamesheslandscapelod
In Oblivion, the LODLevel of Detail meshes can be replaced quad-by-quad only. If one has a lot of landscape changes (like ULUnique Landscapes), the following problems may appear:
The quad meshes do not fit at their borders, because they were created independently "Wall-like" steps between the normal grid and the LODLevel of Detail meshes Floating objects (trees, buildings)
Features of the executable tes4ll
To generate the LODs, tes4ll triangulates the entire worldspace in one single step. The single quads are created and written based on this complete triangulation. This avoids ugly "steps" in the far landscape. tes4ll uses an irregular mesh pattern, whereas the edges of the triangles from the CSConstruction Set are oriented in multiples of 45 degrees. tes4ll is completely configurable by the user by adapting a batch script Single vertex points can be self-defined to avoid gaps, floating trees, etc., wherever you want. Contour lines are added (for better coast lines)
Several algorithms can be used to define individual vertex points density functions:
First and second order derivatives (i.e. based on the slope and the curvature of the heightmap) A peak finder for better mountains Enhanced/reduced density based on the absolute height The number of vertices per quad can be chosen. Depending on the system, a larger or lower number of vertices can be defined. For debugging and better visibility nif files with textures and ps files can be produced. Tes4ll can also produce the normal maps with faked terrain shadows and the meshes for the Immersive Interiors Landscape AddOn (or similar projects).
Installation (since v5.00)
Unpack the tes4ll 7z-archive and move the content into the data directory of Oblivion. When asked, merge the ini-directory of tes4ll into your ini.
Start one of the Windows-bat-files by double clicking on it. At the moment, 3 versions are supported:
"tes4ll_midres.bat" -> "Mid resolution", 10000 vertex points (leads to 20% more triangles as Vanilla "tes4ll_highres.bat" -> "High resolution", 13000 vertex points (leads to 80% more triangles as Vanilla) "tes4ll_ultimate.bat" -> "Ultimate resolution", 18000 vertex points, and a very detailed wall remover (something for high-end graphics cards)
This overwrites your LODLevel of Detail files (hey, did you made a backup?). Your mod list is taken into account. The batch file is written such, that optional parts are automatically included (e.g. a viewpoint in Corinthe and additional vertices for ULUnique Landscapes Rolling hills around the farm)
If you use MPGUI, you also can go into <Oblivion>\Data\ini\tes4ll and double-click on tes4ll_all.mpb. Here you have a hell of options.
Normal map generation
Use tes4ll_normalmaps.bat, if you don't have MPGUI.
Color map generation (since v4.00)
You can run the build-in TES4qLOD with MPGUI (recommended) or by using the bat-file tes4_tes4qlod.bat.