[Seaowl]

Thanks for the reply, Gap.

Have you tried adding a specular map in the alpha channel of the main
(diffuse) texture? A well done specular map can do miracles in increasing the realism of
models.

For shading I have used the „Principled BSDF“ with Cycles Renderer in Blender 2.80-beta.
The Alpha channel of the texture is enabled, but consciously I haven´t added any special specular map.
In the „Principled BSDF“ though, I had to change some values particulary the roughness, to obtain an acceptable result.

But I suppose, it´s far from perfect and I´am thankful for every instruction.
As I said above: I´am at the very beginning of using Blender.
It´s a lot of fun but a ongoing trial and error.

Are the lighthouses set as terrain objects or as land units?
If the latter is true, you can add a LOD model for the GR2 version. Just look at stock
sea/air units to see how their LOD models are set.
If the contrary is true (i.e. the lighthouses are simple terrain objects) no LOD model is
possible, but I am curious to know if you applied this method to increase the rendering
radius of the GR2 model.

In my first attempts I set – as you have shown me – the lighthouse as terrain unit:
The problem was, that the lighthouseflare dissappeared like switched off in a distance of about 2700 meters;
the model itself was visible only a little bit longer (about 3500 m).

Later – likewise following your suggestion – I set the lighthouse as land unit.
Since then visibility is no issue any longer.
There is no noticeable popping up of the model itself.
The flare is visible from about 16-17 km.
(Edit: I refer here to the Dat-file flare. Don´t know how a GR2-lense with Goblineditor set particle-controller will act.)

Of course: the flare of real lighthouses reaches a lot farther.
Though thats a problem to address later.

As shell-unit figures the LCD_Bunker_Large file.
So far I haven´t neither added any LOD-model, nor changed
the Reflect and DMG_col mesh of the original unit.
I will deal with them in the next turn.

Are the texture/materials of the DAT lighthouse version set as in SHIII or SHIV?
SHIII has a limited multi-material support, but SHIV's UnifiedRenderController enables
DAT models to have as many maps and textures as SH5's GR2 models and to similarly
use dds (compressed) textures instead of tga ones. It would be interesting if we could
put side by side a DAT and GR2 model at their respective best, and see how they will
compare in game.

I have used the original SH3-dat.
Never managed to append AO-maps and Bumpmaps to converted SH3 units in SH4.
But – as far as I remember – in KSD-2 (really great mod by the way) there is a simplified model of Flakmonkeys lighthouse with additional Ao-map.
Could try to import it and – if there is any significant difference – post some comparision screens.

I can be wrong, but I seem to see a smoothing problem near the base of the model (below the door). If that's true you can solve it by splitting some of the model edges. Since you are using Blender, there is a edge split modifier you can use for quickly performing that task.

You are right, there is a problem.
Will try to solve it with edge-splitting.

Thanks again to taking the time to answer
and providing all the tips and hints.