Another Screenshot:

The models look extremely detailed. Are these 3D scans or self-made assets?

Most of the 3D objects are my own photogrammetry scans.
The knight and the horse was my first attempt at creating a 3D model using AI, which created a 3D model from just a single photo. Post-processing is then necessary, of course.
The landscape I also created with Photogrammetry. I made hundreds of screenshots with Google Earth and then let the Photogrammetry software create the 3D model of the landscape. And I use my own "planting script" to place the trees on the landscape.

Some of my 3D objects that I scanned in my summer vacation two years ago:

I experimented with local AI based photo-to-3D-model-conversion in the past. I think, currently the best models available are probably Hunyuan 3D 2.1 and Trellis.

I haven't tested online services though.

Your landscapes also look very impressive.

Swimming and diving