GetSurfaceOrientation()

vector CGame::GetSurfaceOrientation ( float x, float z )

inlineprotected

Returns tilt of the ground on the given position in degrees, so you can use this value to rotate any item according to terrain.

См. определение в файле Global/game.c строка 1216

    {
        vector normal = g_Game.SurfaceGetNormal(x, z);
        vector angles = normal.VectorToAngles();
        angles[1] = angles[1]+270; // This fixes rotation of item so it stands vertically. Feel free to change, but fix existing use cases.
        
        //Hack because setorientation and similar functions break and flip stuff upside down when using exactly this vector ¯\_(ツ)_/¯ (note: happens when surface is flat)
        if (angles == "0 540 0")
            angles = "0 0 0";
        return angles;
    }

Перекрестные ссылки g_Game, vector::VectorToAngles() и x.