RW - Spectrum

"Spectrum" is a very versatile modifier to create very different waves. For this purpose you can choose from three different subtypes which are all ruled by the same set parameters: “Sinusoidal”, “Asymmetric”, and “Sharp”. The waves are created within a certain range of frequencies, defined by “Min. freq.” and “Max. freq.”. These parameters are very sensitive and even smallest changes can produce a completely different result. Spectrum types are mostly used as an underlying base wave to get a better behaviour and a more convincing appearance.

"Spectrum" waves can be very fast and therefore it is often necessary to slow down their movement. Since there is no wave speed setting with this type, you have to use higher “FPS output” settings of up to 150 or even 200, while playback is done using the standard frame rate of the used TV or cinematic system, e.g. 30 for NTSC or 24 for HDTV. If you want to use spectrum waves in combination with different modifiers and high “FPS output” values, also consider adjusting the other modifier’s speed setting.

“Sharp” waves, in particular, are not always easy to adjust and usually require some testing. With very large surfaces, spectrum waves tend to produce regular patterns. They are more suitable for small or mid-ranged scenes. Please note that “Sharp” spectrum waves always have a negative vertical offset at the beginning of the simulation – that is important to bear in mind when you are applying crest emitters.

 

 

Active

You can choose between “Yes” and “No”. The active switch is normally only needed with more than one modifier or other sources of wave creation, e.g. travelling objects. Under such circumstances you can disable the appropriate modifier and evaluate the underlying wave structure for fine-tuning.

Weight

With “Weight” it is possible to define a kind of mixing strength. By default, each set of waves contributes to the final result at equal strength and weight. To reduce the influence of a certain modifier, simply decrease its weight. The range starts with 0.0, while 1.0 stands for 100%.

Shape

As already mentioned in the introduction you can choose from three different types:

  • “Sinusoidal” uses standard sine functions in horizontal directions to create a regular pattern. This is most useful for an underlying base wave in combination with other modifiers.
  • “Asymmetric” generates a more realistic surface without regular structures and provides waves of varied heights and widths. This type is also ideal for combinations with the "Fractal" modifier to get a more differentiated look.
  • “Sharp” produces waves with sharp crests, similar to "Statistical Spectrum" waves but based on other rules. Nevertheless it is possible to achieve very realistic cresting waves with this modifier, though without the typical motion patterns of statistical waves.
Min. frec.

This is this minimum frequency of the waves. There should be at least a difference of 0.1 samples between “Min. frec.” and “Max. frec.” to achieve reasonable results.

Max. frec.

To change the maximum frequency of the wave spectrum change this value. The waves’ samples are created from the range between “Min. freq.” and “Max. freq.” With values around 2.0 and above it might be possible that regular patterns appear on the surface. In this case simply reduce this setting.

Samples

This is the number of waves or samples that will be generated from the given frequency range. To achieve wider gaps between the wave crests, reduce “Samples”. For more waves, raise it.

V scale

Change and adjust the vertical height of the waves with this parameter. For a more realistic look avoid very high values. “V scale” is a rather sensitive value, so try to change it in relatively small steps. "V scale" is measured in metres [m].

Angle

Determine the origin and the direction of the waves with this setting. Please be careful with “Angle” and sharp waves. Changes often yield a completely different look, because the sharp crests are influenced by the waves’ direction. This value uses degrees [deg].

 

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