JP4959819B2 - 3D ocean wave display method - Google Patents

Description

  The present invention uses a computer graphics system having a CPU (Central Processing Unit), a GPU (Graphics Processing Unit), and a display, and converts a three-dimensional ocean wave in pixel units in real time. 3D ocean wave display method for displaying by shading (shading calculation and drawing).

  In recent years, with the development of computer graphics systems, it has become possible to perform 3D ocean wave calculations and shading (shading calculation and drawing) in pixel units. In addition, the display device that displays the rendered result has also been improved in resolution and becomes clearer.

  By the way, since the resolution of the display device remains high enough to allow humans to recognize dots, flickering and moire (interference patterns) are not completely eliminated, and the shape of long-distance 3D ocean waves is unclear. become. This problem is known to be improved somewhat by performing anti-aliasing processing by sub-pixel sampling. However, sub-pixel sampling may increase processing and may not be able to maintain real-time characteristics.

  FIG. 5 is a waveform diagram showing a conventional three-dimensional ocean wave display method. As shown in FIG. 5, a composite wave 104 obtained by synthesizing three sine waves 101, 102, and 103 having different periods and three sine waves 101, 102, and 103, which is a basic generation of a three-dimensional ocean wave. is there. If the left side of the synthesized composite wave 104 is the position of the viewpoint in the computer graphics system, it indicates that the right side is farther from the viewpoint. At this time, in FIG. 5, even in a distant place, a wave having a short period is directly calculated as a shadow, and appears as flicker or moire at the time of drawing on the screen.

  FIG. 6 is an example in which a composite wave is drawn by the method of FIG. 5, and moire appears remarkably at a distance (upper part of the screen). Also, flickering occurs when the viewpoint is moved in this state.

JP 2001-184519 A JP-A-8-36633

  An object of the present invention is to provide a three-dimensional ocean wave display method that can reduce flicker and moire in drawing of a three-dimensional ocean wave and can maintain real-time properties.

The present invention relates to a three-dimensional ocean wave display method for performing calculation and shading of a three-dimensional ocean wave on a pixel basis using a computer graphics system having a CPU, a GPU, and a display. Differently, a plurality of waveforms that are attenuated from the vicinity to the far side are created so that the shorter the waveform, the smaller the amplitude in the vicinity of the viewpoint, and a composite wave that combines the plurality of waveforms is created. The shade of each pixel constituting the wave is calculated, and the display device draws the shaded composite wave.

  The three-dimensional ocean wave display method of the present invention has a high possibility of reducing flicker and moire in drawing of a three-dimensional ocean wave and maintaining real-time properties. Therefore, it is possible to display the three-dimensional wave with a sense of incongruity and with emphasized features.

It is a wave form diagram which shows the three-dimensional ocean wave display method which concerns on embodiment of this invention. It is the image which drew the composite wave by the method of FIG. It is explanatory drawing which shows the three-dimensional ocean wave display method which concerns on embodiment of this invention. It is composition explanatory drawing which shows the three-dimensional ocean wave display apparatus which concerns on embodiment of this invention. It is a wave form diagram which shows the conventional three-dimensional ocean wave display method. It is the image which drew the composite wave by the method of FIG.

  Hereinafter, embodiments of the present invention will be described in detail.

  FIG. 1 is an explanatory diagram showing a three-dimensional ocean wave display method according to an embodiment of the present invention. As shown in FIG. 1, three sine waves 1, 2, 3 having different periods and a composite wave 4 obtained by synthesizing three sine waves 1, 2, 3 are shown. The wave 1 having the longest period in the upper stage has no amplitude attenuation from the vicinity of the viewpoint to the distance. The wave 2 having a slightly short period in the middle stage is gradually attenuated so that the attenuation rate of the amplitude becomes maximum (the amplitude disappears) far from the viewpoint. The wave 3 having the shortest cycle in the lower stage has its amplitude sequentially attenuated so that the attenuation rate becomes maximum (no amplitude) between the vicinity of the viewpoint and the distance between them. The composite wave 4 is a wave obtained by synthesizing the three waves 1, 2, and 3.

  FIG. 2 is an image in which a composite wave is drawn by the method of FIG. 1, and a wave having a short period disappears from the shape of the composite wave as it goes farther (upper part of the screen).

  That is, while moire in a distant place is reduced, a wave having a long wavelength is displayed with its characteristics remaining. In addition, flicker does not occur even if the viewpoint is moved in this state. Therefore, it is possible to display the three-dimensional wave with a sense of incongruity and with emphasized features.

FIG. 3 is an explanatory view showing a three-dimensional ocean wave display method according to the embodiment of the present invention. In FIG.
(Original wave height) = Ocean wave wave height at the drawing position (View distance) = Distance from the viewpoint to the drawing position (Start distance) = Distance at which attenuation starts (End distance) = Distance at which attenuation ends (Attenuation rate) = Attenuation rate of amplitude (drawing wave height) = Wave height of ocean wave with attenuation
(Attenuation rate) = {(End distance) − (View distance)} / {(End distance) − (Start distance)}
......... (Formula 1)
However, when (attenuation rate)> 1 (attenuation rate) = 1, when (attenuation rate) <0 (attenuation rate) = 0.
(Drawing wave height) = (Original wave height) × (Attenuation rate) (Equation 2)
It becomes.

  In the above (Equation 1), the three sine waves 1, 2, 3 can be created by adjusting (start distance) and (end distance).

  The waveform in FIG. 3 is one ocean wave, and “X” indicates an attenuation rate depending on the position. However, “X” is set as 1.0 when “X” is larger than 1.0, and as 0.0 when it is smaller than 0.0.

  Here, as an example, the start distance A = 30, the end distance B = 80, and the viewpoint distance C = 100, and the viewpoint distances of the drawing positions [1] to [3] are the drawing position [1] = 12, the drawing position [ When 2] = 45 and the drawing position [3] = 85, the attenuation factor of the wave height at the positions of the drawing positions [1] to [3] is as follows from (Equation 1).

Attenuation rate of drawing position [1]: (80-12) / (80-30) = 1.36
Since the attenuation rate> 1.0 is established, the attenuation rate is 1.0.
Attenuation rate of drawing position [2]: (80−45) / (80−30) = 0.7
Attenuation rate is 0.7
Attenuation rate of drawing position [3]: (80−85) / (80−30) = − 0.1
Since the attenuation rate <0.0 holds, the attenuation rate is 0.0.
FIG. 4 is a configuration explanatory view showing a three-dimensional ocean wave display device according to an embodiment of the present invention. As shown in FIG. 4, a three-dimensional ocean wave display method for calculating and shading three-dimensional ocean waves in pixel units using a computer graphics system (PC: personal computer) having a CPU 11, a GPU 12, and a display 13. The CPU 11 creates a plurality of waveforms having different amplitude attenuation and periods, for example, the waves 1, 2, and 3 in FIG. 1, and synthesized the plurality of waveforms, for example, the waves 1, 2, and 3 in FIG. A composite wave, for example, the composite wave 4 of FIG. 1 is created. The GPU 12 calculates a shadow of each pixel constituting the composite wave, for example, the composite wave 4 of FIG. The display 13 draws and displays a composite wave created by the CPU 11, for example, a composite wave 4 shown in FIG.

  That is, flickering and moire can be reduced by reducing the amplitude of the three-dimensional spatial three-dimensional ocean wave in the computer graphics system according to the distance from the viewpoint. Further, by changing the degree of this reduction for each wave constituting the three-dimensional ocean wave, only a large wave can be emphasized in the distance. Since the above processing is less than the calculation formula of the three-dimensional ocean wave, there is a high possibility that the real-time property can be maintained as compared with the subpixel sampling processing.

  As described above, when a three-dimensional ocean wave (complex wave) model with an expanded sine wave is displayed on a computer graphics system by shading (shading and drawing) a pixel unit, it occurs on the screen. While avoiding the problem of flickering and moire (interference pattern), the characteristics of the composite wave constituting the three-dimensional ocean wave can be left and displayed.

  Note that the present invention is not limited to the above-described embodiment as it is, and can be embodied by modifying the constituent elements without departing from the scope of the invention in the implementation stage. Further, various inventions can be formed by appropriately combining a plurality of constituent elements disclosed in the embodiment. For example, some components may be deleted from all the components shown in the embodiment. Furthermore, you may combine suitably the component covering different embodiment.

  1, 2, 3 ... sine wave, 4 ... composite wave, 11 ... CPU, 12 ... GPU, 13 ... indicator.

Claims (1)

In a 3D ocean wave display method for calculating and shading 3D ocean waves in pixel units using a computer graphics system having a CPU, GPU and display,
The CPU creates a plurality of waveforms that are attenuated from the vicinity to the far side so that the amplitude is different in the vicinity of the viewpoint so that the shorter the waveform, the shorter the period, and the composite wave that combines the plurality of waveforms is created. And
The GPU calculates a shadow of each pixel constituting the composite wave,
3. The three-dimensional ocean wave display method, wherein the display device draws the shaded composite wave.

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