JP2018088146A - Drawing program, drawing method and drawing apparatus - Google Patents

Abstract

PROBLEM TO BE SOLVED: To do drawing based on a point group according to a distance from a look-from point.SOLUTION: A drawing apparatus comprises: a first setting unit for setting a fourth point between a first point and a second point and setting a fifth point between the first point and a third point among a point group including the first point, the second point, and the third point displayed on a screen when the point group specified in coordinates of a three-dimensional space is displayed on the screen on the basis of a specific look-from point; a second setting unit for setting a distance from the specific look-from point of each of the first point, the second point and the third point and setting respective colors of the fourth point and the fifth point in accordance with each color; and a drawing unit for drawing, on the screen, an area including the first point, the fourth point and the fifth point on the basis of the color of the first point, the color of the fourth point and the color of the fifth point.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a drawing program, a drawing method, and a drawing apparatus.

  A technique for drawing an image on a screen based on point cloud data is used. As a related technique, a technique related to three-dimensional image display using a triangle group has been proposed (see, for example, Patent Document 1).

  An image processing method for rendering a two-dimensional pixel image from a plurality of triangular image basic elements to be projected onto an image plane has been proposed (see, for example, Patent Document 2).

Japanese Patent Laying-Open No. 2015-50551 JP 2012-14714 A

  When the color (RGB gradation value) of the pixel inside the triangle created by the triangle group is obtained by linear interpolation based on the point cloud data, the distance from the viewpoint to each point of the point cloud data is not considered. For this reason, it is difficult to represent perspective in an image drawn on the screen.

  As one aspect, an object of the present invention is to perform drawing based on a point cloud according to a distance from a viewpoint.

  In one aspect, the drawing program displays the first point and the second point displayed on the screen when the point group specified in the coordinates of the three-dimensional space is displayed on the screen based on the specific viewpoint. A fourth point is set between the first point and the second point in the point group including the point and the third point, and the first point and the third point A fifth point is set between them, and the first point, the second point, and the third point are distanced from the specific viewpoint, and the first point, the second point, and the third point. 4 and the fifth point are set, and the first point is based on the color of the first point, the color of the fourth point, and the color of the fifth point. And the computer executes a process of drawing an area including the fourth point and the fifth point on the screen.

  According to one aspect, it is possible to perform drawing based on a point group according to the distance from the viewpoint.

It is a figure which shows an example of a drawing apparatus. It is a figure which shows an example which specifies each point represented by a two-dimensional coordinate from point cloud data. It is a figure which shows an example of a triangle group. It is a figure which shows an example of the setting of the setting point in embodiment. It is a figure which shows an example of the graph which shows the color according to the position in embodiment. FIG. 6 is a diagram (part 1) illustrating an example of drawn image data. FIG. 6 is a second diagram illustrating an example of drawn image data. It is a flowchart which shows an example of the flow of the process of embodiment. It is a figure which shows an example of the setting of the setting point in a modification. It is a figure which shows an example of the graph which shows the color according to the position in a modification. It is a flowchart which shows an example of the flow of the process of embodiment. It is a figure which shows an example of the hardware constitutions of a drawing apparatus.

<Example of Drawing Device of Embodiment>
Hereinafter, embodiments will be described with reference to the drawings. FIG. 1 shows an example of a drawing apparatus 1 according to the embodiment. The drawing device 1 is connected to the display device 2 and the input device 3. The drawing device 1 may be, for example, a computer that performs predetermined image processing and displays the image subjected to the image processing on the screen of the display device 2.

  The display device 2 is a display, for example. An image (image data) drawn by the drawing device 1 is displayed on the display device 2. The input device 3 may be, for example, a mouse or a keyboard.

  The drawing apparatus 1 includes a control unit 11, a storage unit 12, a coordinate specifying unit 13, a triangle group generation unit 14, a first setting unit 15, a second setting unit 16, and a drawing unit 17. The control unit 11 performs various controls. For example, control for displaying image data on the display device 2 and control for receiving an operation from the input device 3 are performed.

  The storage unit 12 stores various data. In the embodiment, the storage unit 12 stores point cloud data. The point cloud data is data in which points specified in the coordinates of the three-dimensional space are collected, and a predetermined image is drawn using the point cloud data.

  For example, the drawing apparatus 1 may acquire point cloud data based on sensor data measured by a predetermined sensor (such as a three-dimensional sensor), and store the acquired point cloud data in the storage unit 12. For example, the drawing apparatus 1 may acquire point cloud data via the Internet, and store the acquired point cloud data in the storage unit 12. Further, the point cloud data may be stored in the storage unit 12 in advance.

  The coordinate specifying unit 13 projects each point included in the point cloud data represented by the coordinates of the three-dimensional space on the screen of the display device 2. Therefore, the coordinate specifying unit 13 specifies the two-dimensional coordinates of each point when each point included in the point cloud data is displayed on the screen of the display device 2.

  The triangle group generation unit 14 generates a triangle by connecting three points adjacent to each other represented by two-dimensional coordinates. In the embodiment, it is assumed that the point cloud data includes four or more points. Therefore, a plurality of the above triangles are generated. Hereinafter, a plurality of triangles are defined as a triangle group. The triangle group is sometimes referred to as a Delaunay diagram.

  The first setting unit 15 sets predetermined points (hereinafter referred to as setting points) on three sides for each triangle of the generated triangle group. The second setting unit 16 sets a color at the set point set by the first setting unit 15. In the embodiment, the second setting unit 16 sets an intermediate color between the colors of the two vertices with respect to the set point set on the side connecting the two vertices among the three vertices of the triangle.

  The drawing unit 17 performs color linear interpolation on each of the four triangles (hereinafter referred to as divided triangles) divided by the straight line connecting the three set points. The drawing unit 17 performs linear interpolation of colors based on the colors of the vertices of the divided triangles, and draws a two-dimensional image based on the point cloud data. Note that the drawing unit 17 may perform arbitrary interpolation processing according to the distance from the new hand, instead of linear interpolation processing.

<Example of triangle group generation>
FIG. 2 shows an example of specifying each point represented by two-dimensional coordinates from point group data represented by coordinates in a three-dimensional space. A three-dimensional space 21 in FIG. 2 indicates a predetermined three-dimensional space based on the viewpoint 22.

  The viewpoint 22 is a virtual viewpoint. For example, when the viewpoint 22 is a camera, the three-dimensional space 21 is determined according to the position, orientation, angle of view, and the like of the camera. The three-dimensional space 21 includes a point group.

  The coordinate specifying unit 13 specifies the two-dimensional coordinates on the screen 23 for each point included in the point group represented by the three-dimensional coordinates. Thereby, each point included in the point cloud data represented by the three-dimensional coordinates is projected on the screen 23. The screen 23 is a screen of the display device 2. The shape of the screen 23 is a rectangle.

  FIG. 3 shows an example of a triangle group generated by the triangle group generation unit 14. As illustrated in FIG. 3, the triangle group generation unit 14 connects three points P adjacent to each other to generate a plurality of triangles. The point P is represented by two-dimensional coordinates.

  The triangle group generation unit 14, when a region (outermost peripheral region) formed by connecting a plurality of points P located on the outermost side among the plurality of points P does not include a partial region of the screen 23, A new point is set at the vertex of the screen 23. In the example of FIG. 3, the point P1 is a new point. Since the point P1 is a point generated by the triangle group generation unit 14, it is not a point based on the point group data. The point P1 is an example of a sixth point.

  If the point P1 is not set, the outermost peripheral area of the triangle group does not include a part of the area of the screen 23. In this case, a part of the image based on the point cloud data is not displayed on the screen 23 of the display device 2.

  By setting the point P1, the triangle group generation unit 14 causes the outermost peripheral area to include the entire area of the screen 23 when the outermost peripheral area of the triangle group does not include a part of the area of the screen 23. Then, a point P1 is set at the vertex of the screen 23.

  When the point P1 is set, a new outermost peripheral region is formed. In this case, the new outermost peripheral area including the point P <b> 1 includes all areas of the screen 23. Therefore, it is avoided that a part of the image based on the point cloud data is not displayed on the screen 23 of the display device 2.

  The point P1 may be set at a position other than the vertex of the screen 23. For example, the point P1 may be set at any position of the boundary of the screen 23 or the region outside the boundary. When the point P1 is set at such a position, the new outermost peripheral area including the point P1 includes the entire area of the screen 23. When the point P1 is set at the vertex of the screen 23, the position of the point P1 can be easily specified.

  The triangle group generation unit 14 sets an arbitrary color at the above-described point P1. For example, the triangle group generation unit 14 may set the background color of the screen 23 to the point P1. When the outermost peripheral area of the triangle group does not include a plurality of portions of the area of the screen 23, the triangle group generation unit 14 may set a plurality of points P1.

<Example of interpolation processing>
Next, an example of interpolation processing will be described. A triangle T shown in FIGS. 4A and 4B represents one triangle among a plurality of triangles included in the triangle group generated by the triangle group generation unit 14. The triangle T may be any triangle.

  The vertices of the triangle T are point A, point B, and point C. In the example of FIG. 4, the point A is an example of a first point. Point B is an example of a second point. Point C is an example of a third point. The point A may be the second point or the third point. The point B may be the first point or the third point. The point C may be the second point or the third point.

  The three points A, B, and C are points specified by the two-dimensional coordinates on the screen 23 that are included in the point cloud data represented by the coordinates in the three-dimensional space, and are displayed on the screen 23. It is. Therefore, the points A, B, and C correspond to the points of the point group data.

  As shown in the example of FIG. 4A, it is assumed that the point A is a point whose distance from the viewpoint 22 is “La”. Point B is a point whose distance from the viewpoint 22 is “Lb”. Further, it is assumed that “La> Lb”.

  Therefore, when the viewpoint 22 is used as a reference, the point A is farther than the point B. The first setting unit 15 sets a point D between the points A and B. For example, the first setting unit 15 sets the point D on the side AB connecting the point A and the point B.

  If the point D is between the points A and B, the point D may be set at a position shifted from the side AB. Point D is an example of a fourth point.

  The first setting unit 15 sets the point D according to the ratio of the distance La from the viewpoint 22 to the point A and the distance Lb from the viewpoint 22 to the point B. In the embodiment, the first setting unit 15 internally divides the side AB by the reciprocal number “1 / La” of the distance La and the reciprocal number “1 / Lb” of the distance Lb, and sets the internally divided point as a point D. Is set on the side AB.

  The point D may be set at a position shifted from a position obtained by internally dividing the side AB by the reciprocal of the distance. For example, the point D may be set to a position slightly shifted toward the point A or the point B from the position obtained by internally dividing the side AB by the reciprocal of the distance.

  As described above, since the distance La and the distance Lb have a relationship of “La> Lb”, the point D is set at a position near the point A and at a position far from the point B on the side AB. .

  Similarly, the first setting unit 15 sets a point E between the points A and C and sets a point F between the points A and B. Point E is an example of a fifth point. The point D may be a fifth point. The point F may be a fifth point. The point E or the point F may be a fourth point. Point D, point E, and point F are the set points described above.

  Hereinafter, the point D is referred to as a set point D, the point E is referred to as a set point E, and the point F is referred to as a set point F. The set points D, E, and F are points set by the first setting unit 15 and are different from points corresponding to the display of the point cloud data on the screen 23 (for example, point A, point B, and point F). It is.

  The distance from the viewpoint 22 to the point C is “Lc”, and the relationship between the distance Lc and the distance La is “La> Lc”. The first setting unit 15 internally divides the side AC by the reciprocal number “1 / Lc” of the distance Lc and the reciprocal number “1 / La” of the distance La, and uses the internally divided point as a point E on the side AC. Set to.

  As described above, since “La> Lc”, the point E is set to a position close to the point A and set to a position far from the point C.

  Further, it is assumed that the difference between the distance Lb and the distance Lc is small. In this case, the first setting unit 15 sets the point F according to the ratio of the distance Lb from the viewpoint 22 to the point B and the distance Lc from the viewpoint 22 to the point C. It is set near the midpoint on BC.

  The second setting unit 16 sets colors at the three set points D, E, and F. The second setting unit 16 sets an intermediate color between the color of point A and the color of point B to point D, sets an intermediate color between the color of point A and the color of point C to point E, An intermediate color with the color of point C is set to point F.

  In the embodiment, the color is expressed by a vector of three primary colors of R (red), G (green), and B (blue). For example, when the color vector of the point A is represented by (R, G, B) = (255, 0, 0), the color of the point A is red.

  Further, when the color vector of the point B is represented by (R, G, B) = (0, 255, 0), the color of the point A is green.

  In the above case, for the point D set between the point A and the point B, the second setting unit 16 calculates the color vector of the average value of the color vector of the point A and the color vector of the point B. Set (R, G, B) = (128, 128, 0). Thereby, an intermediate color between red and green is set at the point D.

  The value of the intermediate color vector may be a value deviated from the average value of the two color vectors. Further, the color of the set point set by the second setting unit 16 may be specified by information other than the vector values of the three primary colors of RGB.

  The drawing unit 17 divides the triangle T by a straight line connecting the three set points of the triangle T. As a result, four triangles (hereinafter referred to as divided triangles) are generated. In the example of FIG. 4B, divided triangles T1, T2, T3, and T4 are generated. For example, the divided triangle T1 is a region including the point A, the point D, and the point E.

  The drawing unit 17 performs linear interpolation on the divided triangle T1 based on the color of the point A, the color of the point D (intermediate color), and the color of the point E (intermediate color). Thereby, color information is set in the area of the divided triangle T1.

  The drawing unit 17 similarly performs linear color interpolation for the divided triangles T2, T3, and T4. Thereby, the color information is also set for each of the divided triangles T2, T3, and T4.

  For example, as described above, it is assumed that the point A is red and the point B is green. Point C is blue (color vector (R, G, B) = (0, 0, 255)). In this case, in the area of the divided triangle T1, the color of the area near the point A is red.

  As described above, the drawing unit 17 performs linear color interpolation. Further, since the color of the set point D is set to an intermediate color between red and green, the color of the area in the vicinity of the set point D gradually approaches the set intermediate color from red or green.

  Similarly, since the color of the set point E is set to an intermediate color between red and blue, the color in the area near the set point E gradually approaches the set intermediate color from red or blue. Since the color of the set point F is set to an intermediate color between blue and green, the color of the area near the set point F approaches the set intermediate color from blue or green.

  Accordingly, the vicinity of the boundary of the divided triangle T4 has gradation. The drawing unit 17 performs linear interpolation of colors based on the color of the set point D (intermediate color), the color of the set point E (intermediate color), and the color of the set point F (intermediate color). Thereby, as described above, color information is set in the area of the divided triangle T4.

  The colors of the three vertices (set point D, set point E, and set point F) of the divided triangle T4 are set to intermediate colors. Therefore, the color in the vicinity of the center of the divided triangle T4 is less affected by the colors of the points A, B, and F.

  As described above, the first setting unit 15 internally divides the side AB by the reciprocal number “1 / La” of the distance La and the reciprocal number “1 / Lb” of the distance Lb, and sets the internally divided points. A point D is set on the side AB.

  Further, since the distance from the viewpoint 22 is La and the distance from the viewpoint B is Lb (La> Lb), the point A is farther than the point B when the viewpoint 22 is used as a reference. In position. Accordingly, the set point D is set at a position close to the point A and far from the point B on the side AB.

  Therefore, focusing on the side AB, the range from the point A to the set point D is a range where the influence of the color of the point A is large, and the range from the point B to the set point D is a range where the influence of the color of the point B is large. The distance from the point A to the set point D is shorter than the distance from the point B to the set point D.

  Therefore, of the points A and B, the influence of the color of the point B having the shorter distance from the viewpoint 22 on the triangle T is that the color of the point A having the longer distance from the viewpoint 22 is the triangle. It is higher than the degree of influence on T.

  For this reason, the influence of the color of the point A located at a far position with respect to the viewpoint 22 is reduced, and the influence of the color of the point B located at a close position is increased.

  Similarly, the set point E is set at a position closer to the point A having a longer distance from the viewpoint 22 than the point C having a shorter distance from the viewpoint 22 in the side AC. Therefore, with the viewpoint 22 as a reference, the influence of the color of the point A at a distant position is reduced, and the influence of the color of the point C at a close position is increased.

  Further, the set point F is set near the middle point on the side BC. Therefore, with the viewpoint 22 as a reference, the influence of the color of the point B and the influence of the color of the point C are approximately the same.

  From the above, in the triangle T shown in the example of FIG. 4B, the color of the point A far from the viewpoint 22 has little influence on the triangle T, and the color of the point B close to the viewpoint 22 and the point C close to the viewpoint 22 The influence of the color of on the triangle T is large. For this reason, the image of the triangle T is an image representing the perspective from the viewpoint 22.

  FIG. 5 is an example of a graph showing colors according to positions on the side AB. As described above, the set point D is set at a position closer to the point B than the point A. Accordingly, the set point D is set between the midpoint on the side AB (the midpoint between the points A and B) and the point A.

  As shown in the example of the graph of FIG. 5, the range in which the color of the point B affects the side AB is wider than the range in which the color of the point A affects. Since the point B is closer to the viewpoint 22 than the point A, the influence of the color of the point B is larger than the color of the point A on the side AB. Therefore, the color depends on the distance from the viewpoint 22. The influence degree of is reflected in the image. The same applies to the other sides.

  The drawing unit 17 performs the above-described processing on all the triangles T included in the triangle group, and draws an image. For each triangle T, the color influence is reflected in the image according to the distance from the viewpoint 22, so the image drawn by the drawing unit 17 is an image reflecting the perspective from the viewpoint 22.

  The control unit 11 performs control to display the image drawn by the drawing unit 17 on the display device 2. By the control, the above image is drawn on the screen 23 of the display device 2.

  FIG. 6A shows an example of an image drawn without setting the set points described above. In the example of FIG. 6A, the image data includes a tree 23A and a three-dimensional object 23B. It is assumed that the tree 23A is located closer to the three-dimensional object 23B with the viewpoint 22 as a reference.

  Since the distance from the viewpoint 22 is not considered in the image in the example of FIG. 6A, the difference in color influence between the tree 23A near the viewpoint 22 and the three-dimensional object 23B far from the viewpoint 22 is small. Therefore, the perspective of the image in the example of FIG. 6A is not easily expressed by the tree 23A and the three-dimensional object 23B.

  FIG. 6B shows an example of an image when the above-described set points are set and various processes of the embodiment are performed. Since the image in the example of FIG. 6B is an image in which the distance from the viewpoint 22 is taken into consideration, the difference in color influence between the tree 23A close to the viewpoint 22 and the three-dimensional object 23B far from the viewpoint 22 is large. . Accordingly, the image in the example of FIG. 6B is an image in which perspective is expressed by the tree 23A and the three-dimensional object 23B.

  FIG. 7A shows another example of an image drawn without setting the above-described set points. FIG. 7B shows another example of an image when the above-described set points are set and various processes of the embodiment are performed.

  Compared to the image in the example in FIG. 7A, the image in the example in FIG. 7B is an image in which perspective is expressed by the three-dimensional object 23C and the three-dimensional object 23D. Therefore, drawing according to the distance from the viewpoint 22 can be performed based on the point cloud data.

  In the embodiment, the drawing unit 17 performs linear color interpolation processing on each triangle T of the triangle group described above, and draws an image based on the point cloud data. For example, a predetermined area (for example, a circle area) is virtually set at each point on the two-dimensional coordinates based on the point cloud data, and the set area is colored to draw image data. .

  However, in this case, an image is drawn reflecting information (false information) of a virtual area not included in the point cloud data. Therefore, due to the fact that false information is reflected in the image, the reproducibility of the image based on the point cloud data is lowered.

  In the embodiment, as described above, the drawing unit 17 performs linear color interpolation processing on each triangle T of the above-described triangle group, and draws an image based on the point group data. Therefore, since false information is not reflected, the reproducibility of the image based on the point cloud data is increased. Further, in the embodiment, since processing of false information is not performed, the amount of calculation is reduced as compared with the case where false information is reflected in an image.

  As described above, the point P1 (for example, a point set at the vertex of the screen 23) is a point that is not based on the point group data, but the point P1 is the same as the point A, the point B, or the point C. Processing is performed. For example, when the triangle T is formed by the point A, the point B, and the point P1, when the point P1 is assumed to be the point C, the same process as described above is performed.

  Accordingly, a set point is set between the point A and the point P1. The set point is an example of a seventh point. A set point is set between the point B and the point P1. The set point is an example of an eighth point.

<Flowchart showing an example of processing flow of embodiment>
With reference to FIG. 8, the drawing apparatus 1 inputs point cloud data (step S1). The input point cloud data is stored in the storage unit 12. The drawing apparatus 1 sets the viewpoint 22 (step S2). For example, when the control unit 11 of the drawing apparatus 1 accepts an operation for setting the viewpoint 22 from the input device 3, the drawing apparatus 1 sets the viewpoint 22 based on the operation.

  When the control unit 11 of the drawing apparatus 1 accepts an operation for changing the viewpoint 22 from the input device 3, the drawing apparatus 1 changes the set viewpoint 22 based on the operation. Thereby, an image is drawn based on point cloud data from an arbitrary viewpoint 22.

  The coordinate specifying unit 13 projects each point included in the point cloud data represented by the coordinates of the three-dimensional space onto the screen 23 of the display device 2 (step S3). Thereby, the two-dimensional coordinate of each point when each point included in the point cloud data is displayed on the screen 23 of the display device 2 is specified.

  When the outermost peripheral area does not include a part of the area of the screen 23, the triangle group generation unit 14 sets the point P1 at the vertex of the screen 23 so that the outermost peripheral area includes all areas of the screen 23 ( Step S4).

  Thereby, it is avoided that a part of the image based on the point cloud data is not displayed on the screen 23 of the display device 2. The triangle group generation unit 14 sets the background color of the screen 23 at the above-described point P1.

  When the point P1 is set at the vertex of the screen, the triangle group generation unit 14 generates a triangle group including the point P1 (step S5). The first setting unit 15 performs a process of setting set points on three sides for each triangle (step S6).

  The first setting unit 15 sets set points for the two vertices of the triangle T according to the ratio of the distances from the viewpoint 22. For example, the first setting unit 15 internally divides the side AB by the reciprocal of the distance from the viewpoint 22 to the point A and the reciprocal of the distance from the viewpoint 22 to the point B, and sets the internally divided point as a set point D as an edge. Set on AB.

  The second setting unit 16 sets an intermediate color as the set point color set by the first setting unit 15 (step S7). For example, the second setting unit 16 sets an intermediate color between the color of the point A and the color of the point B at the set point D described above. The second setting unit 16 sets the color of the set point for each triangle.

  The drawing unit 17 divides the triangle T by a straight line connecting the three set points of the triangle T. As a result, four divided triangles T1, T2, T3, and T4 are generated (step S8).

  The drawing unit 17 performs color linear interpolation processing on each of the divided triangles T1, T2, T3, and T4 (step S9). As a result, the color information set for the triangle T becomes color information reflecting the perspective with the viewpoint 22 as a reference.

  The drawing unit 17 performs the process of step S9 for all the triangles T. As a result, the drawn image becomes an image corresponding to the distance from the viewpoint 22 and becomes an image reflecting the perspective based on the viewpoint 22.

<Modification>
Hereinafter, modifications will be described. FIG. 9A shows an example of set points D, E, and F set on each side of the triangle T in the modification. The first setting unit 15 sets the set point D at the midpoint between the points A and B, sets the setpoint E at the midpoint between the points A and C, and the midpoint between the points B and C. Set the set point F to.

  The second setting unit 16 sets the color of the set point D for the set point D according to the ratio of the distance La from the viewpoint 22 to the point A and the distance Lb from the viewpoint 22 to the point B. In the modification, the second setting unit 16 internally divides the color of the point A and the color of the point B by the reciprocal “1 / La” of the distance La and the reciprocal “1 / Lb” of the distance Lb.

  As described above, the color of the point A is red, and the color vector of the point A is represented by (R, G, B) = (255, 0, 0). The color of the point B is green, and the color vector of the point B is represented by (R, G, B) = (0, 255, 0).

  As described above, it is assumed that the relationship between the distance La and the distance Lb is “La> Lb”. In this case, if the color of the point A and the color of the point B are internally divided by the reciprocal number “1 / La” of the distance La and the reciprocal number “1 / Lb” of the distance Lb, the ratio of the color of the point A becomes low. The ratio of B color is increased.

  For example, when the distance La is twice the distance Lb (La = 2 × Lb), the color vector of the set point D is (R, G, B) = (85, 170, 0). Accordingly, the color of the set point D has a higher influence of the color of the point B than the influence of the color of the point A.

  FIG. 10 is an example of a graph of a modified example showing colors according to positions on the side AB. The position of the set point D is the midpoint between the points A and B. The “internally divided color” indicates a color obtained by internally dividing the color of the point A and the color of the point B by the reciprocal number “1 / La” of the distance La and the reciprocal number “1 / Lb” of the distance Lb.

  As shown in the example of FIG. 10, the influence of the color of the point A on the range from the point A to the set point D (the midpoint between the points A and B) is low on the side AB. On the other hand, the degree of influence of the color of point B on the range from point B to set point D is high.

  With the viewpoint 22 as a reference, the point A is closer to the point B. In the side AB, the influence degree of the color of the point A is higher than the influence degree of the color of the point B. Therefore, in the side AB of the triangle T, a difference in perspective can be given between the points A and B.

  The second setting unit 16 also internally divides the colors of the two points by the reciprocal of the distance from the viewpoint 22 for the set point E and the set point F as in the set point D. Then, the second setting unit 16 sets the internally divided colors as the set point E and the set point F.

  For each triangle T, the drawing unit 17 performs linear color interpolation on the divided triangles T1, T2, T3, and T4. Thereby, the rendered image data becomes an image reflecting the perspective from the viewpoint 22 to each point.

  Next, a processing flow of the modification will be described with reference to the flowchart of FIG. The flowchart of FIG. 11 differs from the flowchart of FIG. 8 in steps S6 and S7. Since each step other than step S6 and step S7 is the same as that of FIG. 8, description is abbreviate | omitted.

  The first setting unit 15 sets a set point at the midpoint of the three sides of the triangle T (step S6-1). The second setting unit 16 internally divides the two colors by the reciprocal of the distance from the viewpoint 22, and sets the internally divided color as a set point (step S7-1).

  As described above, also in the modified example, since the process considering the distance from the viewpoint 22 is performed, the perspective can be reflected in the image drawn by the drawing unit 17.

<Example of hardware configuration of drawing apparatus>
Next, an example of the hardware configuration of the drawing apparatus 1 will be described with reference to the example of FIG. As shown in the example of FIG. 12, a processor 111, a random access memory (RAM) 112, and a read only memory (ROM) 113 are connected to the bus 100. An auxiliary storage device 114, a medium connection unit 115, and an input / output interface 116 are connected to the bus 100.

  The processor 111 executes a program expanded in the RAM 112. As a program to be executed, a program for performing processing in the embodiment may be applied.

  The ROM 113 is a non-volatile storage device that stores programs developed in the RAM 112. The auxiliary storage device 114 is a storage device that stores various information, and for example, a hard disk drive, a semiconductor memory, or the like may be applied. The medium connection unit 115 is provided so as to be connectable to the portable recording medium 120.

  As the portable recording medium 120, a portable memory (for example, a semiconductor memory), an optical disk (for example, a Compact Disc (CD), a Digital Versatile Disc (DVD)), or the like may be applied. A program for performing the processing of the embodiment may be recorded on the portable recording medium 120.

  For example, the display device 2 and the input device 3 are connected to the input / output interface 116. In the drawing apparatus 1, the control unit 11, the coordinate specifying unit 13, the triangle group generation unit 14, the first setting unit 15, the second setting unit 16, and the drawing unit 17 execute a given program by the processor 111. May be realized. The storage unit 12 may be realized by the RAM 112, the auxiliary storage device 114, or the like.

  The RAM 112, the ROM 113, the auxiliary storage device 114, and the portable recording medium 120 are all examples of a tangible storage medium that can be read by a computer. These tangible storage media are not temporary media such as signal carriers.

<Others>
The present embodiment and modification examples are not limited to the above-described embodiment, and various configurations or embodiments can be employed without departing from the gist of the present embodiment and modification examples.

DESCRIPTION OF SYMBOLS 1 Drawing apparatus 2 Display apparatus 3 Input device 11 Control part 12 Memory | storage part 13 Coordinate specific | specification part 14 Triangle group production | generation part 15 1st setting part 16 2nd setting part 17 Drawing part 111 Processor 112 RAM
113 ROM

Claims (10)

When the point group specified in the coordinates of the three-dimensional space is displayed on the screen based on the specific viewpoint, the first point, the second point, and the third point displayed on the screen are included. In the point group, a fourth point is set between the first point and the second point, and a fifth point is set between the first point and the third point. ,
According to the distance from the specific viewpoint of each of the first point, the second point, and the third point, and the respective colors, the fourth point and the fifth point Set each color,
An area including the first point, the fourth point, and the fifth point based on the color of the first point, the color of the fourth point, and the color of the fifth point Drawing on the screen,
A drawing program for causing a computer to execute processing. The fourth point and the fifth point are points different from the point group corresponding to the display on the screen of the point group specified in the coordinates of the three-dimensional space.
The drawing program according to claim 1. The position of the fourth point on the screen is determined according to the ratio of the distance from the viewpoint to the first point and the distance from the viewpoint to the second point in the coordinates of the three-dimensional space. To be
The drawing program according to claim 1. The color of the fourth point to be set is an intermediate color between the color of the first point and the color of the second point.
The drawing program according to claim 3, characterized in that: The fourth point is a midpoint between the first point and the second point on the screen, and the color of the fourth point is determined from the viewpoint in the coordinates of the three-dimensional space. Determined according to the ratio of the distance to the first point and the distance from the viewpoint to the second point;
The drawing program according to claim 1. The process of drawing the area includes a process of specifying a color in the area by linear interpolation based on the color of the first point, the color of the fourth point, and the color of the fifth point. ,
The drawing program according to claim 1. Set a sixth point on the boundary of the screen or outside the boundary,
A seventh point is set between the first point and the sixth point; an eighth point is set between the second point and the sixth point;
According to the distance from the specific viewpoint of each of the first point and the second point, and the respective colors of the first point, the second point, and the sixth point, Set the colors of the seventh point and the eighth point,
An area including the first point, the seventh point, and the eighth point based on the color of the first point, the color of the seventh point, and the color of the eighth point Drawing on the screen,
The drawing program according to claim 1, wherein the processing is executed by a computer. The sixth point is set to the vertex of the screen;
The drawing program according to claim 7. When the point group specified in the coordinates of the three-dimensional space is displayed on the screen based on the specific viewpoint, the first point, the second point, and the third point displayed on the screen are included. In the point group, a fourth point is set between the first point and the second point, and a fifth point is set between the first point and the third point. ,
According to the distance from the specific viewpoint of each of the first point, the second point, and the third point, and the respective colors, the fourth point and the fifth point Set each color,
An area including the first point, the fourth point, and the fifth point based on the color of the first point, the color of the fourth point, and the color of the fifth point Drawing on the screen,
A drawing method, wherein a computer executes a process. When the point group specified in the coordinates of the three-dimensional space is displayed on the screen based on the specific viewpoint, the first point, the second point, and the third point displayed on the screen are included. In the point group, a fourth point is set between the first point and the second point, and a fifth point is set between the first point and the third point. A first setting unit;
According to the distance from the specific viewpoint of each of the first point, the second point, and the third point, and the respective colors, the fourth point and the fifth point A second setting unit for setting each color;
An area including the first point, the fourth point, and the fifth point based on the color of the first point, the color of the fourth point, and the color of the fifth point A drawing unit for drawing on the screen;
A drawing apparatus comprising: