JP4777181B2 - Image special effect device, image special effect method - Google Patents

Description

  The present invention relates to an image special effect device and an image special effect method used for video production and the like, and in particular, performs illumination processing in consideration of the relationship between a light source and a viewpoint, expresses a real special effect in real time, and a variety of special effects. It is intended to simplify and miniaturize an apparatus that can deal with effect images.

  As shown in FIG. 10, the conventional image special effect device includes a frame memory 102 and a read address calculation unit 109 that calculates the image special effect read address 108 from a sequential write address 105. FIG. 10 is a block diagram of a conventional image special effect device.

  By reading the input image 101 sequentially written in the frame memory 102 with the sequential write address 105 and reading the output image 103 from the frame memory 102 with the image special effect read address 108 calculated by the image special effect read address calculation unit 109. Various video effects such as page turning effect and ball effect are applied to the image.

  In the conventional image special effect device, the method for calculating the display screen horizontal direction address when realizing the page turning effect is as shown in FIG. 11, starting from the write address x on the sequential display screen horizontal direction X13. For each of the flat surface portion 15, the lower surface curved surface portion 16, the upper surface curved surface portion 11, and the upper surface flat surface portion 12, an Xeffect expressed by the following equation is calculated. In FIG. 11, Z14 indicates the viewpoint direction 14 (z axis), R2 indicates the effect radius 2 (r), and θz40 indicates the angle formed by the normal direction vector and the viewpoint direction Z14. FIG. 11 is a diagram for explaining horizontal coordinate calculation specifications in a conventional image special effect device.

(Lower plane part 15) Xeffect = x
(Lower curved surface portion 16) Xeffect = rθz = r × arcsin (x / r)
(Upper curved surface portion 11) Xeffect = πr / 2−rθz = πr / 2−r × arcsin (x / r)
(Top Plane 12) Xeffect = πr / 2−x

  As shown in FIG. 12, the readout address calculation method in the display screen vertical direction starts from the write address y in the vertical direction Y22 on the sequential display screen, and the lower surface plane portion 15, the lower surface curved surface portion 16, the upper surface curved surface portion 11, and the upper surface plane. For each part 12, Yeffect expressed as the following equation is calculated. Further, A31 in FIG. 12 indicates the upper surface movement amount. FIG. 12 is a diagram for explaining vertical coordinate calculation specifications in a conventional image special effect device.

  Xeffect is display screen horizontal direction data for generating various video effects such as page turning effect and ball effect from the horizontal display screen horizontal direction data of Cartesian coordinates. is there. Yeffect is display screen vertical direction data for generating various video effects such as page turning effect and ball effect from sequential display screen vertical direction data of Cartesian coordinates. is there. Xeffect and Yeffect are converted into an image special effect read address 108.

  Further, in order to give a lighting effect to the obtained special effect image, by mixing table values stored with a plurality of illumination patterns corresponding to a plurality of predetermined effect surface shapes, various shapes can be obtained. An apparatus capable of obtaining an illumination effect on an effect surface is known (for example, see Patent Document 1).

In general, the calculation method in the case of realizing the specular reflection illumination effect is as follows. When the light source vector is L and the normal vector of the effect surface is N, the reflection vector R is equal to regardless of the shape of the effect surface.
R = 2 (L · N) N−L · ·· Equation 1
It is.
JP 05-143746 A

  However, the above-described conventional special effect device has the inconvenience of determining various illumination patterns in advance and determining the optimal combination of illumination patterns according to the effect surface. Furthermore, when a special effect function is newly added, an optimal combination may not be found with the mounted illumination pattern.

  In a Field Programmable Gate Array (FPGA) equipped with many multipliers, it is easy to implement the calculation circuit of Formula 1 that can deal with lighting effects on various effect surfaces.

  FIG. 13 shows a normal vector calculation formula in the case of the effect of turning pages from right to left on the display screen. FIG. 13 is a diagram showing normal vectors in a conventional image special effect device. From FIG. 13, the normal vectors of the lower plane portion 15, the lower curved portion 16, the upper curved portion 12, and the upper plane portion 11 are expressed as follows:

  In this case, as shown in FIG. 14, the normal vector display screen horizontal direction component 6 is discontinuous in the amount of change in the connection portion between the upper surface flat portion 12 and the upper curved surface portion 11, and the normal vector display screen horizontal direction For component 6, the amount of change in the connecting portion between the lower flat surface portion 15 and the lower curved surface portion 16 becomes discontinuous. As a result, the lighting effect obtained from Equation 1 also becomes discontinuous at the joint between the flat surface portion and the curved surface portion, resulting in an unnatural lighting effect.

  For example, the upper surface normal vector horizontal direction component 6 of the upper surface plane portion 12 is 0, but the upper surface normal vector horizontal direction component 6 of the upper surface curved surface portion 11 is x / r (sin θz). Further, the lower surface normal vector horizontal direction component 17 of the lower surface flat portion 15 is 0, but the lower surface normal vector horizontal direction component 17 of the lower surface curved surface portion 16 is −x / r (−sin θz). FIG. 14 is a diagram showing display screen horizontal component normal vector characteristics in a conventional image special effect device.

  The present invention has been made in view of the above circumstances, and an object thereof is to provide an image special effect device and an image special effect method that can realize a natural lighting effect and can be downsized.

  In order to achieve the above object, the first image special effect device according to the present invention is configured to illuminate with light from a light source when viewed from an arbitrary viewpoint on a plane having a plane and a curved surface for image information relating to an input image. An image special effect device to which an effect is added and outputs a video signal obtained by mapping the image information on the surface, comprising a viewpoint direction vector indicating a vector of the viewpoint direction, a horizontal coordinate of the surface, and A cosine value calculation unit that calculates a cosine value of an angle formed with a normal vector at the position of the surface based on the position of the vertical coordinate and the shape of the surface; the cosine value as a component in the viewpoint direction; 1−cosine value) or (−1 + cosine value) as a normal vector vector for calculating a vector having the horizontal coordinate component as a calculation normal vector, and the calculation normal vector And a lighting effect calculation unit for calculating the lighting effect based on the light.

  With this configuration, a natural lighting effect can be realized and the apparatus can be downsized. For example, it is necessary to add a large-scale new calculation circuit by calculating the amount of change in the horizontal direction component based on the calculation result of the viewpoint direction component from the normal vector of the connecting portion between the page turning plane part and the curved surface part. However, since it can be made continuous, the apparatus can be miniaturized while realizing a natural lighting effect.

  Further, in the second image special effect device of the present invention, when the normal vector calculation unit is a page turning shape having the upper surface and the lower surface, the cosine value calculated by the cosine value calculation unit, The vertical coordinate component of the calculation normal vector is calculated based on the vertical coordinate position and the upper surface movement amount based on the vertical displacement amount of the upper surface and the lower surface.

  With this configuration, the cosine value calculated for normal vector calculation is used for the calculation of the page turning vertical coordinate direction, so that the top and bottom surfaces do not overlap with each other when the page turns from right to left. Even without adding a large-scale new calculation circuit, it is possible to reduce the size of the apparatus while obtaining a natural page turning effect.

  The third image special effect device according to the present invention includes a sine value calculation unit that calculates a sine value of an angle formed by the viewpoint direction vector and the normal vector, and a sine value calculated by the sine value calculation unit. And (1−cosine value) and (−1 + cosine value) of the angle calculated by the normal vector calculation unit, the calculation method for using the lighting effect calculation unit to calculate a lighting effect. And a selection unit that selects as a component of the horizontal coordinate of the line vector.

  With this configuration, the horizontal component normal vector can be switched and output, so that a general lighting effect for the ball effect can be calculated in addition to the page turning effect without adding a large-scale new calculation circuit. Can be miniaturized.

The first image special effect method of the present invention uses an image special effect device, and the image information relating to the input image includes light from a light source when viewed from an arbitrary viewpoint on a plane having a plane and a curved surface. adds lighting effect, an the image information by mapping image special effect how to output a video signal obtained on the surface, the cosine value calculation unit to the image special effect apparatus is provided, the direction of the viewpoint Cosine value calculation for calculating the cosine value of the angle formed by the viewpoint direction vector indicating the vector of the surface, the position of the horizontal coordinate and the vertical coordinate of the surface, and the normal vector at the surface position based on the shape of the surface And a normal vector calculation unit included in the image special effect device, wherein the cosine value is a component in a viewing direction, and (1−cosine value) or (−1 + cosine value) of the angle is the horizontal A normal vector calculating step of calculating a vector with component in the direction coordinate as a calculation usage normal vector, lighting effects calculator the image special effect apparatus is provided, based on the calculated usage normal vector, and calculates the lighting effects And a lighting effect calculation step .

  By this method, a natural lighting effect can be realized and the apparatus can be miniaturized. For example, it is necessary to add a large-scale new calculation circuit by calculating the amount of change in the horizontal direction component based on the calculation result of the viewpoint direction component from the normal vector of the connecting portion between the page turning plane part and curved surface part. However, since it can be made continuous, the apparatus can be miniaturized while realizing a natural lighting effect.

  In the present invention, even for an image special effect having an effect surface connecting a plane and a curved surface such as page turning, the normal vector of the plane component of the display screen calculated from (1 cosine value) or (cosine value −1). The connecting portion between the flat surface and the curved surface is smooth, a natural lighting effect can be realized by the simple calculation of Equation 1, and the apparatus can be downsized. A natural and smooth shading effect can also be realized.

  In addition, the image special effect device of the present invention changes the shape to turn the page, for example, from right to left, from left to right, from top to bottom, or from bottom to top, and the top and bottom surfaces of the page turning shape overlap. The page where the upper surface and the lower surface do not overlap by reusing the calculation result of (1-cosine value) and (cosine value-1) calculated by lighting processing and multiplying the constant by moving the upper surface position The turning effect can be realized and the apparatus can be miniaturized.

  The image special effect device of the present invention can calculate a normal normal vector by switching (1-cosine value) or (cosine value-1) to a sine value. Widely applicable.

  Hereinafter, an image special effect device according to an embodiment of the present invention will be described with reference to the drawings.

により余弦値３(cosθz)を求める。法線ベクトル計算部７は、余弦値計算部４による計算結果である余弦値３(cosθz)を入力し、法線ベクトルの水平方向成分６および法線ベクトルの視点方向成分５を出力する。 (First embodiment)
First, the illumination effect on the upper surface in the page turning effect will be described.
FIG. 1 is a diagram showing a configuration of an image special effect device 100 according to the first embodiment of the present invention. The image special effect device 100 includes a cosine value calculation unit 4 and a normal vector calculation unit 7. The cosine value calculation unit 4 inputs the horizontal coordinate 1 (x) (X1 in FIG. 1) and the effect radius 2 (r) (R2 in FIG. 1),

The cosine value 3 (cosθz) is obtained by The normal vector calculation unit 7 receives the cosine value 3 (cos θz) that is the calculation result of the cosine value calculation unit 4 and outputs the horizontal direction component 6 of the normal vector and the viewpoint direction component 5 of the normal vector.

  Here, assuming that the horizontal direction component 6 of the normal vector for realizing the top lighting effect in the page turning effect is n_vector_x and the viewpoint direction component 5 of the normal vector is n_vector_z, the normal vector N = (n_vector_x, 0, n_vecotor_z). The normal vector calculation unit 7 outputs, as n_vector_z, a cosine value 3 (cos θz) which is the same calculation as the input value by the cosine value calculation unit 4. For n_vector_x, the normal vector calculation unit 7 calculates n_vector_x = 1−cos θz using the calculation result of n_vector_z.

となり、上面平面部１２の法線ベクトルNは、
Ｎ＝(0,0,1)
となり、n_vector_xの特性は、図３に示すように、上面曲面部１１と上面平面部１２の接続部分で変化量は連続となる。 At this time, the normal vector N of the upper curved surface portion 11 is

The normal vector N of the upper surface plane part 12 is
N = (0,0,1)
As shown in FIG. 3, the amount of change in the characteristics of n_vector_x is continuous at the connection portion between the upper curved surface portion 11 and the upper flat surface portion 12.

  Here, FIG. 2 is a detailed explanatory diagram of the normal vector in the first embodiment of the present invention, and the directions of the thick arrows in the upper surface plane portion 12 and the lower surface curved surface portion 11 indicate the direction of the normal vector. . FIG. 3 is a diagram showing the horizontal component normal vector characteristics in the first embodiment of the present invention.

  As a result, the lighting effect at the connecting portion of the upper surface flat portion 12 and the upper curved surface portion 11 of the page turning effect as shown in FIG. 2 can be continuously changed, and a visually natural lighting effect can be obtained. Obtainable.

Next, the illumination effect on the lower surface in the page turning effect will be described.
FIG. 4 is a diagram showing a configuration of the second image special effect device 100B according to the first embodiment of the present invention. The image special effect device 100B basically has the same configuration as that of the image special effect device 100 shown in FIG. 1, but includes a normal vector calculation unit 7B instead of the normal vector calculation unit 7.

  The normal vector calculation unit 7B obtains n_vector_z as in FIG. Then, n_vector_x of the lower curved surface portion 16 is calculated as n_vector_x = cos θz−1 using the calculation result of n_vector_z.

下面平面部１５の法線ベクトルNは、
Ｎ＝(0,0,1)
となり、n_vector_xの特性は、図６に示すように、下面曲面部１６と下面平面部１５との接続部分で変化量は連続となる。 At this time, the normal vector N of the lower curved surface portion 16 is

The normal vector N of the lower plane part 15 is
N = (0,0,1)
As shown in FIG. 6, the amount of change in the characteristics of n_vector_x is continuous at the connection portion between the lower curved surface portion 16 and the lower flat surface portion 15.

  Here, FIG. 5 is a detailed explanatory diagram of the second normal vector in the first embodiment of the present invention, and the direction of the thick arrow in the lower plane portion 15 and the lower curved portion 16 indicates the direction of the normal vector. ing. FIG. 6 is a diagram showing the second horizontal component normal vector characteristic in the first embodiment of the present invention.

  As a result, the lighting effect at the connecting portion of the lower surface flat portion 15 and the lower curved surface portion 16 of the page turning effect as shown in FIG. 5 can be continuously changed, and a visually natural lighting effect can be obtained. Obtainable.

  According to the image special effect device 100 according to the first embodiment of the present invention, the image information related to the input image is based on light from a light source when viewed from an arbitrary viewpoint on a plane having a plane and a curved surface. An image special effect device 100 that outputs a video signal obtained by mapping image information on a surface to which a lighting effect is added, a viewpoint direction vector indicating a viewpoint direction vector, a horizontal coordinate of a surface, and a vertical direction A cosine value calculation unit 4 that calculates a cosine value of an angle formed by a normal vector at a surface position based on a coordinate position and a surface shape, and the cosine value as a component in a viewing direction, an angle (1-cosine value) Or, a normal vector calculation unit 7 that calculates a vector having (−1 + cosine value) as a horizontal coordinate component as a calculation normal vector, and illumination based on the calculation normal vector With the configuration including the lighting effect calculation unit that calculates the effect, for example, the amount of change in the horizontal direction component of the normal vector N of the connecting portion between the page turning plane portion and the curved portion is calculated as the viewpoint direction component. By obtaining from the result, it is possible to make it continuous without adding a large-scale new calculation circuit, so that the device can be miniaturized while realizing a natural lighting effect.

  In the present embodiment, the effect of turning the page in the horizontal direction has been described. However, other directions may be used, and in this case, the vertical direction component of the normal vector may be considered in the same manner as the horizontal direction component.

  In the present embodiment, the page turning effect has been described, but an image special effect that connects a plane and a curved surface or a curved surface and a curved surface may be used.

(Second Embodiment)
Next, an image special effect device 200 according to the second embodiment of the present invention will be described.
FIG. 7 is a diagram showing a configuration of an image special effect device 200 according to the second embodiment of the present invention. The image special effect device 200 includes a cosine value calculation unit 4, a normal vector calculation unit 18, and a page turning vertical direction coordinate calculation unit 19. The page turning vertical direction coordinate calculation unit 19 is an example of a part of the normal vector calculation unit.

  The cosine value calculation unit 4 is the same as that described in the first embodiment mobile phone. The normal vector calculation unit 18 has the same function as the normal vector calculation unit 7 or the normal vector calculation unit 7B in the first embodiment.

  The page turning vertical coordinate calculation unit 19 calculates the normal vector for illumination processing by calculating the cosine value 3 (cosθz) calculated by the cosine value calculation unit 4 and the upper surface movement amount 31 (a) indicating the amount of positional deviation between the upper surface and the lower surface. (A31 in FIG. 7) and the vertical coordinate 20 (y) (Y20 in FIG. 7) are used to perform calculation for obtaining Yeffect. The calculation for calculating the Yeffect, that is, the calculation performed by the page turning vertical coordinate calculation unit 19 is shown for each of the lower plane portion 15, the lower curved portion 16, the upper curved portion 11, and the upper plane portion 12 as follows. It is. FIG. 8 is a diagram for explaining the page turning effect vertical coordinate calculation specification in the second embodiment of the present invention.

(Lower plane part 15) Yeffect = y
(Lower curved surface portion 16) Yeffect = y−a {1−cosθz}
(Upper curved surface portion 11) Yeffect = y−a {1 + cosθz}
(Top Plane 12) Yeffect = y-2a

  According to the image special effect device 200 in the second embodiment of the present invention as described above, when the page turning vertical coordinate calculation unit 19 is a page turning shape having an upper surface and a lower surface, a cosine value calculation unit. The vertical coordinate component of the normal vector for calculation is calculated based on the cosine value calculated by 4, the position of the vertical coordinate, and the amount of upper surface movement based on the amount of vertical displacement of the upper and lower surfaces. By using cosθz, which has been calculated for normal vector calculation, in the calculation of the vertical coordinate direction of page turning, for example, the top and bottom surfaces do not overlap due to a shape change that turns the page from right to left. Even if a new calculation circuit is not added, the device can be downsized while a natural page turning effect is obtained.

  In the present embodiment, the effect of turning pages from right to left has been described, but other directions may be left to right, top to bottom, and bottom to top.

(Third embodiment)
Next, an image special effect device 300 according to the third embodiment of the present invention will be described.
FIG. 9 is a diagram showing a configuration of an image special effect device 300 according to the third embodiment of the present invention. The image special effect device 300 includes a sine value calculation unit 50, a cosine value calculation unit 4B, a normal vector calculation unit 18, and a selector 25. The selector 25 is an example of a selection unit.

を行い、余弦値３(cosθz)を出力する。法線ベクトル計算部１８は第２の実施形態において説明したものと同様である。 The sine value calculation unit 50 inputs the horizontal coordinate 1 (x) (X1 in FIG. 9) and the effect radius 2 (r) (R2 in FIG. 9), and sets the sine value 23 (sinθz) = x / r. calculate. The cosine value calculation unit 4B inputs the sine value 23 (sinθz) and calculates the cosine value.

To output a cosine value of 3 (cos θz). The normal vector calculation unit 18 is the same as that described in the second embodiment.

  The selector 25 inputs the sine value 23 (sinθz) = x / r calculated by the sine value calculation unit 50 and the calculation result performed by the normal vector calculation unit 18, and selects either one by the mode switching signal 24. The normal vector horizontal direction component 6 is output as n_vector_x. The selector 25 can switch the horizontal component normal vector for the effect of turning the page from right to left and the horizontal component normal vector for the ball effect, and output the result as the normal vector horizontal component 6.

  According to the image special effect device 300 in the third embodiment of the present invention as described above, the sine value calculation unit 50 that calculates the sine value of the angle formed by the viewpoint direction vector and the normal vector, and the sine value calculation unit 50 One of (1−cosine value) and (−1 + cosine value) of the sine value calculated by the normal vector calculation unit 18 and the angle calculated by the normal vector calculation unit 18 is used for the calculation of the lighting effect by the lighting effect calculation unit. By having a selector 25 that selects as a horizontal coordinate component of the calculation normal vector to be switched, the horizontal component normal vector can be switched and output without adding a large-scale new calculation circuit. In addition to the page turning effect, a general lighting effect for the ball effect can be calculated, and the apparatus can be miniaturized.

  In this embodiment, the case of switching the effect of turning the page from right to left and the lighting effect of the ball effect has been described. However, other than the image special effect that connects a curved surface and a curved surface other than the page turning effect, other It is also possible to switch to the image special effect.

  INDUSTRIAL APPLICABILITY The present invention can process lighting effects of various image special effects in real time with a downsized configuration, and is useful as an image special apparatus that can be widely used in various fields in which video / image production / editing is performed. is there.

The block diagram which shows the structure of the image special effect apparatus in the 1st Embodiment of this invention. Detailed illustration of normal vectors in the first embodiment of the present invention The figure which showed the horizontal direction component normal vector characteristic in the 1st Embodiment of this invention The block diagram which shows the structure of the 2nd image special effect apparatus in the 1st Embodiment of this invention. Detailed explanatory diagram of the second normal vector in the first embodiment of the present invention The figure which showed the 2nd horizontal direction component normal vector characteristic in the 1st Embodiment of this invention The block diagram which shows the structure of the image special effect apparatus in the 2nd Embodiment of this invention. The figure for demonstrating the page turning effect vertical direction coordinate calculation specification in the 2nd Embodiment of this invention. The block diagram which shows the structure of the image special effect apparatus in the 3rd Embodiment of this invention. Block diagram showing the configuration of a conventional image special effect device The figure for demonstrating the horizontal coordinate calculation specification in the conventional image special effect apparatus The figure for demonstrating the vertical direction coordinate calculation specification in the conventional image special effect apparatus The figure which showed the normal vector in the conventional image special effect device The figure which showed the display screen horizontal direction component normal vector characteristic in the conventional image special effect device

Explanation of symbols

100, 100B, 200, 300 Special equipment for image effects
X1 horizontal coordinate
R2 Effect radius 3 Cosine value 4, 4B Cosine value calculation unit 5 Normal vector viewpoint direction component 6 Normal vector horizontal direction component 7, 7B Normal vector calculation unit 11 Upper surface curved surface portion 12 Upper surface plane portion
X13 Display screen horizontal direction
Z14 View direction 15 Lower plane part 16 Lower curved surface part 18 Normal vector calculation part 19 Page turning vertical direction coordinate calculation part
Y20 vertical coordinate
Y22 Display screen vertical direction 23 Sine value 24 Mode selection signal 25 Selector
A31 Upper surface movement amount θz40 Angle formed by viewing direction and normal vector 50 Sine value calculation unit 101 Input image 102 Frame memory 103 Output image 105 Sequential write address 108 Image special effect read address 109 Read address calculation unit

Claims (4)

Illumination effect by light from a light source when viewed from an arbitrary viewpoint on a plane having a plane and a curved surface is added to the image information about the input image, and a video signal obtained by mapping the image information on the plane is obtained. An image special effect device for output,
Calculates the cosine value of the angle formed by the viewpoint direction vector indicating the direction vector of the viewpoint, the position of the horizontal and vertical coordinates of the surface, and the normal vector at the position of the surface based on the shape of the surface A cosine value calculation unit,
A normal vector calculation unit that calculates a vector having the cosine value as a component in the viewing direction and the angle (1−cosine value) or (−1 + cosine value) as the horizontal coordinate component as a calculation normal vector;
A lighting effect calculation unit for calculating the lighting effect based on the calculation normal vector;
An image special effect device. The image special effect device according to claim 1,
The normal vector calculator is
When the shape is a page turning shape having an upper surface and a lower surface, it is based on the cosine value calculated by the cosine value calculation unit, the position of the vertical coordinate, and the amount of positional deviation in the vertical direction of the upper surface and the lower surface. An image special effect device that calculates a component of the vertical coordinate of the normal vector for calculation based on an upper surface movement amount. The image special effect device according to claim 1,
A sine value calculator for calculating a sine value of an angle formed by the viewpoint direction vector and the normal vector;
One of the sine value calculated by the sine value calculation unit and the angle calculated by the normal vector calculation unit (1−cosine value) and (−1 + cosine value) is used as the lighting effect calculation unit. A selection unit for selecting as a component of the horizontal coordinate of the normal vector for calculation used to calculate the lighting effect by
An image special effect device. Using an image special effect device, the image information relating to the input image is added with an illumination effect by light from a light source when viewed from an arbitrary viewpoint on a plane having a plane and a curved surface, and the image information is added to the plane. an image special effect how to output a video signal obtained by mapping,
The cosine value calculation unit included in the image special effect device includes a viewpoint direction vector indicating a vector of the viewpoint direction, the position of the horizontal coordinate and the vertical coordinate of the surface, and the position of the surface based on the shape of the surface. A cosine value calculating step for calculating a cosine value of an angle formed with the normal vector at
Normal vector calculating unit included in the image special effect apparatus, components of the viewpoint direction the cosine value, of the angle vector with components of the horizontal coordinate (1-cosine) or (-1 + cosine) A normal vector calculation step for calculating as a normal vector for calculation;
The lighting effect calculation unit provided in the image special effect device , the lighting effect calculation step of calculating the lighting effect based on the normal vector for calculation,
An image special effect method.

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