Contents
(1) Provide simple information for a boat hull shape, and have RenderWorld generate the wake;
(2) Read in an existing wake from a file.
In either option, the boat wake has a fixed shape that is permanent in time.
The portion of the ocean file which sets up a wake disturbance is shown below. The
render_disturbances parameter effects the rendering of the boat area of
the wake and is described in section
Ocean Disturbances.
Reference is made to an additional file (wake.dat) which contains details about the internal structure of the wake.number_disturbances 1
render_disturbances black
grid_type wake
n_points_x 512
n_points_y 512
dx 2.5
dy 2.5
file wake.hdf
generate_file no
input_file wake.dat
position_x 0
position_y 0
direction 180
velocity 0
end
The position (
position_x, position_y) and direction of the wake are with respect to the ocean: rotating and/or moving the ocean takes the wake along with it. To generate a new wake from RenderWorld, the file wake.dat has the form:
RenderWorld_data_file wake 1 1
generate_file yes
filename wake.hdf
length 10
width 3
depth 1
0.1
end
lined hull bottom shape. Finally, taper is a parameter which allows the user to control the tapering of the wake as a function of distance from the hull. Larger values of taper reduce the effective length of the wake.
The option generate_file no means that the wake will be read from the file wake.hdf. When a wake already exists as a file in the correct format, the wake.dat file has the lines:
RenderWorld_data_file wake 1 1
generate_file no
filename wake.hdf
length 10
width 3
depth 1
end
The wake is stored as a 2D array of float numbers representing surface displacement, in the hdf file format. After the wake has been generated, it can be edited using any image processing software that reads and writes hdf format. In fact, the wake need not be generated by RenderWorld. Any arbitrary 2D array can represent a wake simply by creating it in the hdf floating point format.