plot_bath: Plot bathymetry with transparency control
In vinayudyawer/KUD3D: Visualising animal telemetry data in three dimensions

Displays the shaded map in 3D with the 'rgl' package. Altered version of the plot_3d function to allow adjustment of transparency

plot_bath(hillshade, heightmap, zscale = 1, water = FALSE, waterdepth = 0,
  watercolor = "lightblue", wateralpha = 0.5, theta = 45, phi = 45,
  fov = 0, zoom = 1, background = "white", windowsize = c(600, 600),
  ...)

`hillshade`	Hillshade/image to be added to 3D surface map.
`heightmap`	A two-dimensional matrix, where each entry in the matrix is the elevation at that point. All points are assumed to be evenly spaced.
`zscale`	Default '1'. The ratio between the x and y spacing (which are assumed to be equal) and the z axis. For example, if the elevation levels are in units of 1 meter and the grid values are separated by 10 meters, 'zscale' would be 10. Adjust the zscale down to exaggerate elevation features.
`water`	Default 'FALSE'. If 'TRUE', a water layer is rendered.
`waterdepth`	Default '0'. Water level.
`watercolor`	Default 'lightblue'. Color of the water.
`wateralpha`	Default '0.5'. Water transparency.
`theta`	Default '45'. Rotation around z-axis.
`phi`	Default '45'. Azimuth angle.
`fov`	Default '0'–isometric. Field-of-view angle.
`zoom`	Default '1'. Zoom factor.
`background`	Default 'grey10'. Color of the background.
`windowsize`	Default 'c(600,600)'. Width and height of the 'rgl' device displaying the plot.
`...`	Additional arguments to pass to the 'rgl::par3d' function.
`baseshape`	Default 'rectangle'. Shape of the base. Options are c("rectangle","circle","hex").
`solid`	Default 'TRUE'. If 'FALSE', just the surface is rendered.
`soliddepth`	Default 'auto', which sets it to the lowest elevation in the matrix minus one unit (scaled by zscale). Depth of the solid base.
`solidcolor`	Default 'grey20'. Base color.
`solidlinecolor`	Default 'grey30'. Base edge line color.
`shadow`	Default 'TRUE'. If 'FALSE', no shadow is rendered.
`shadowdepth`	Default 'auto', which sets it to 'soliddepth - soliddepth/10'. Depth of the shadow layer.
`shadowcolor`	Default 'grey50'. Color of the shadow.
`shadowwidth`	Default 'auto', which sizes it to 1/10th the smallest dimension of 'heightmap'. Width of the shadow in units of the matrix.
`waterlinecolor`	Default 'NULL'. Color of the lines around the edges of the water layer.
`waterlinealpha`	Default '1'. Water line tranparency.
`linewidth`	Default '2'. Width of the edge lines in the scene.
`lineantialias`	Default 'FALSE'. Whether to anti-alias the lines in the scene.