Originally written in 2018, so might be better solutions out there.

The repository contains a helpful file with Z-heights for any given X,Y coordinate in GTA:V. I originally wrote a client-side script in JavaScript back in 2018 that would teleport the player in a grid pattern and grab the heights around him using

entity.getHeight(X, Y, Z, atTop, inWorldCoords);

from https://wiki.rage.mp/index.php?title=Entity::getHeight This is not perfect, and I'm pretty sure that there exists proper height maps that would produce the same or something of higher quality.

The result of running the height grabber was the file data_file/GTAV_HeightMap_Data.data. All heights are within a bounded box with a lower left point and upper right point:

• LOWER LEFT: (-4100,-4300)
• UPPER RIGHT: (4300, 7825)

This covers the land of San Andreas and must of the surrounding waters. Beaware that some heights might be 0, but my experience is that this is only a few of them.

Just invoke GetHeightAtXY(...) from MapDataLibrary as such:

float height = GetHeightAtXY(goto.X, goto.Y);
NAPI.Entity.SetEntityPosition(ply, new Vector3(goto.X, goto.Y, height));

Distributed under the MIT License. See LICENSE.txt for more information.