Ripples


In this example, we place a circular ripple in the image (as if a rock or something had just hit the water). We specify that there will be one disturbance on the ocean, a ripple. Note that the render_disturbances parameter has no effect for a ripple. The ripple will be centered at x=0, y=0 relative to the origin of the ocean. Additional input information about the ripple is in the file ripple.dat. Since this is a relatively large ripple, we choose a resolution of 0.5 meters. For smaller ripples, you would want a smaller number here. The values for dx and dy here as well as dx in the ripple file should all be same. In the ripple.dat file itself, we set the starting time for the ripple at minus five seconds, so that our first frame at time zero will be five seconds into the ripple. The ripple has a radius of 4 meters. Since the ripple obviously grows with time, this is just the initial size. The v_o parameter controls the direction and speed of the water in the center of the ripple at the instant that the ripple starts. In this case, the water in center of the ripple is moving upward at 10 meters per second in the first moments of the ripple. This number may be either positive or negative.

       RenderWorld_data_file ocean 5 5
       n_points_x 1024 1 
       n_points_y 1024 1 
       dx 0.1 
       dy 0.1 
       spectrum_file spec2.dat 
       generate_file yes 
       random_seed 91401 
       end 
       number_aux_oceans 0 
       number_disturbances 1
       render_disturbance  black 
       grid_type ripple 
       n_points 1000 
       not_used 1 
       dx 0.5 
       dy 0.5 
       file spectra_rip.dat 
       generate_file yes 
       file: ripple.dat 
       centerPoint_x 0 
       centerPoint_y 0 
       end 
       box_depth 20. 
       reference_time 0 
       surface_type round 
       radius 6371230 
       max_distance 100 
       double_distance 60 
       wind_type fixed 
       wind_direction 90 
       wind_velocity 8 
       waves yes 
       water_type 3 
       external_exact no 
       glitter yes 
       whitecaps no 
       textures no 
       sunbeams no
       exclude_items no 
       number_of_bands 3 
       band_ids 1 2 3 
       index_of_refraction 1.34 1.34 1.34 
       end 
The ripple file ripple.dat is shown below.

reference_time -5. 
       radius 4.0 
       v_o 10.0 
       n_points 1000 
       dx 0.5 


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