Ground and river models are just for visualization in scene.

Models have V-Ray materials in maya scene.

Preview images are rendered by V-Ray

I didn' t use any HDR file, only used V-Ray lights and environment override with color ramp node

I used V-Ray layers on renders for color correction, saturation and style.

Textures designed and exported from Substance Painter.

Textures from substance painter are in seperate rar file

Texture resolution is 4096 x 4096

Maya project has its own texture files in sourceimages folder.

Clean Maya Outliner and History

Clean geometry, no ngons or other bad geometry.

Models also have uv maps of their own.

Uv maps are unwrapped and non-overlapping

If you want to change color or other features you can use the Substance Painter file.

If you use Maya scene for render, you will get same results as the render images.