JPH03257683A - Three-dimensionally analyzed figure drawing device - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed Description of the Invention] <Industrial Application Field> The present invention relates to a three-dimensional analytical drawing drawing device for drawing three-dimensional coordinate data as an analytical drawing on a display means such as a CRT or a liquid crystal screen, and further relates to More specifically, the present invention relates to a three-dimensional analytical drawing drawing device that is capable of drawing natural three-dimensional analytical drawings.

<Prior Art> FIG. 4 is a configuration block diagram showing an example of a conventional three-dimensional analytical drawing device.

In the figure, 1 is a memory in which three-dimensional coordinate data is stored, and 2 is a memory that stores coordinate data (Xs, Ys, Zs) from this memory 1.
), (Xe, Ye, Ze) in the drawing order, and 3 is a coordinate conversion means that converts the three-dimensional coordinates into two-dimensional coordinates for drawing a projection view.

Reference numeral 4 designates a drawing data generation means for inputting the two-dimensional coordinate data from the coordinate conversion means 3, 5 a first comparator, and 6 a MAX buffer in which the maximum value of coordinates is stored. The first comparator 5 compares the contents of the MAX buffer 6 with the drawing data generating means 4.
The drawing data from the drawing data generating means 4 is compared with the drawing data from the drawing data generating means 4, and the switch SW is driven according to the comparison result to control the application of the drawing data from the drawing data generating means 4 to the display means 8.

A second comparator 7 compares the drawing data applied to the display means 8 with the contents of the MAX buffer 6, and updates the contents of the MAX buffer 6 according to the comparison result.

<Problems to be Solved by the Invention> In conventional drawing devices configured in this way, the hidden line processing method is configured to draw only when both ends of the line segment to be drawn are not hidden by the line in front. For this reason, there was a problem in that when there is a sudden change, specifically when a line segment is hidden between one unit pixel, a disconnection occurs.

FIG. 5 shows an example of a three-dimensional analysis diagram displayed by a conventional device.

The present invention has been made in view of the above-mentioned problems, and an object of the present invention is to provide a drawing device that can draw a three-dimensional analysis diagram using line segments without disconnections without significantly increasing the time required for display.

Means for Solving the Problems> The present invention for solving the above problems includes a memory in which three-dimensional coordinate data is stored, and coordinate data (Xs, Ys, Zs) (Xe, Ye, Ze) from this memory.
) in the order of drawing; a coordinate conversion means that converts the three-dimensional coordinates into two-dimensional coordinates for drawing a projection diagram; and drawing data that inputs the two-dimensional coordinate data from the coordinate conversion means. a generating means; a display means for displaying the drawing data generated by the drawing data generating means; a MAX buffer in which a maximum value of coordinates is stored; and comparing the contents of the MAX buffer with the drawing data from the drawing data generating means. , a first comparator that controls the sending of the drawing data applied from the drawing data generation means to the display means according to the comparison result, compares the drawing data applied to the display means with the contents of the MAX buffer, and A second comparator updates the contents of the MAX buffer according to the comparison result, inputs two-dimensional coordinate data from the coordinate conversion means, and data from the MAX buffer, and generates drawing data for the portion where the line segment is hidden. It consists of a high-resolution drawing data generation means.

<Operation> In the present invention, the newly added high-resolution drawing data generation means combines two-dimensional coordinate data from the coordinate conversion means and M
Input data from the AX buffer and generate drawing data for the portion where the line segment is hidden.

The drawing data generated here is applied to the display means according to the output of the first comparator, and the portion where the line segment is hidden by the line segment in the foreground is displayed with higher resolution than the internal pixels. .

<Example> Embodiments of the present invention will be described in detail below with reference to the drawings.

FIG. 1 is a block diagram showing an embodiment of the present invention. In the figure, parts corresponding to those in FIG. 4 are denoted by the same reference numerals, and explanations of their operations will be omitted.

In the apparatus of the present invention, two-dimensional coordinate data (Xs, Ys) (Xe, Ye) output from the coordinate conversion means 3,
A high-resolution drawing data generation means 9 is provided which inputs data from the MAX buffer 6, and the drawing data generated here is sent to a switch S controlled according to the output of the first comparator 5.
The signal is configured to be applied to the display means 8 via W2.

The operation of the device configured as described above will be explained as follows.

First, the MAX buffer 6 is initialized. This MAX buffer 6 is composed of a memory having elements of the calculated number of pixels in the X-axis direction of the drawing area, for example 1024 points, and as an initial value, a value smaller than the minimum value of the y-coordinate axis of the drawing area is input. be done.

Next, the coordinate reading means 2 reads the three-dimensional coordinate (usually the X and Y coordinates are equally spaced) data (Xs, Ys) stored in the three-dimensional coordinate data storage means 1.

Zs), (Xe, Ye, Ze) are read out in the drawing order. The data is read out in order, starting from the line segment data at the front when drawing. These three-dimensional coordinate data are two-dimensional coordinate data (Xs, Ys) for drawing a projection diagram by the coordinate conversion means 3.

(Xe, Ye).

Drawing data generation means 4. 1st. Second comparator 5°7, M
A circuit constituted by the AX buffer 6 and high-resolution drawing data generation means performs classification of drawing data and drawing processing according to this classification.

Now, the coordinates (calculated pixel numbers) of both end points of the line segment to be drawn are (ixl, 1yl).

(Lx2, 1y2), and the contents of MAX buffer 6 are
If it is expressed as max (n) (n is the pixel number),
The comparator 5 classifies the following three cases.

A) iyl≧max(ixl).

iy2≧max(Lx2) ・If both ends are visible B) iyl<max (ixl).

i y2<max (i x2) ...if both ends are not visible C) iyl≧max (ixl)+ iy2<max (Lx2) or i yl<max (ixl)+ iy2≧max (Lx2) ...one side If only the edges of the image are visible, then the following drawing process is performed depending on each of these cases.

In case A), the two-line bone is drawn as is.

In case of B), no double-line bones are drawn.

In the case of C): Using the high-resolution drawing data generation means 9,
This line segment is drawn from one visible end point to the intersection of the line segments drawn by max (the method for calculating this intersection will be explained later).

Here, the second comparator 7 compares the coordinates of the drawn line segment with the contents of the MAX buffer 6, and if the contents of the MAX buffer 6 are smaller, updates the contents of the MAX/< buffer 6.

The calculation for finding the intersection in case (C) is as follows.

(a) End point coordinates of two intersecting line segments (calculated pixel number)
seek.

In the range of ixl≦i x<i x2, ((ly2-iyl)/(1x2-ixl))(Lx-
ixl)”iyl a*ax(ix).

1(1y2-iyl)/(ix2-1xl)l (ix
+1-1xl)+iyl <saw(lx+1>) or ((iy2-1yl)/(Lx2-1xl)l(ix+
1-1xl)+iyl<wax(lx).

t(1y2-1yl)/(ix2-1xl)l (Ix
+1-1xl)+lyl≧wax (i x village) Find ix that satisfies the following.

At this time, 1xcl=ix ixc2-ix+1 iycl= 1(iy2-iyl)/(Lx2-ix
l)) (Ixcl-1xi)+1yliyc2= 1
(iy2-iyl)/ (Lx2-ixl)l (Ix
c2-ixl)+iyLiyg+l-wax(ixcl
) iyw2=s+ax(ixc2).

(b) Next, calculate the coordinates of the intersection (coordinates where the calculated pixel number is treated as a real value). Coordinates of the intersection (x c,
y c) is basically given by the following equation.

xc-(c*b-b*f)/Δ yc-(a*f-c*d)/Δ Δ-a*b-b*d a”tyc2-tyct b=ixcl-1xc2 c=(fy* 2-2-1y book 1xcl-(ixc2-L
xcl) + fymld-jy厘2-2-1y However, Δ ε ε is a small constant determined by calculation accuracy, or when xc5ixcl or xc≧1xc2, xc”(fxcl+fxc2)/2 yc-(iyml+iym2)/2 .

In the process in case (C) above, such calculations are performed by the high-resolution drawing data generation means 9. Therefore, calculation time is required compared to case (A), but calculations only need to be performed for condition (C), which is classified according to the first comparator 5, so there are many changes. If it is not data, there will be no significant increase in calculation time.

In the above embodiment, the hidden line processing is performed using the MAX buffer 6, but by using a similar method, the MIN buffer is also used to draw a line segment that is visible from the bottom displayed in the foreground. You may also do so.

FIGS. 2 and 3 are diagrams showing examples of analytical diagrams drawn according to the present invention. There are no unnatural disconnections as seen in the conventional example, and a diagram that is easy to analyze is obtained.

<Effects of the Invention> As explained in detail above, according to the present invention, hidden line processing is performed by calculating with high resolution only the vicinity where the line segment to be drawn is hidden by the line in the foreground. It is possible to draw a natural and easy-to-analyze 3D analysis diagram without significantly increasing calculation time.

[Brief explanation of drawings]

Figure 1 is a configuration block diagram showing an embodiment of the present invention, Figures 2 and 3 are diagrams showing an example of an analytical diagram drawn by the present invention, and Figure 4 is a conventional three-dimensional analytical diagram drawing device. FIG. 5 is a diagram showing an example of a display of a three-dimensional analysis diagram by a conventional device. FIG. 1 1...Three-dimensional coordinate data storage memory 2...Three-dimensional coordinate data reading means 3...Coordinate conversion means 4...Drawing data generation means 5...First comparator 6...・MAX buffer 7...Second comparator 8...Display means 9...High resolution drawing data generation means

Claims (1)

[Claims] A memory storing three-dimensional coordinate data, and coordinate data (Xs, Ys, Zs), (X
e, Ye, Ze) in the order of drawing; a coordinate conversion means that converts the three-dimensional coordinates into two-dimensional coordinates for drawing a projection view; and a coordinate conversion means that reads out the two-dimensional coordinate data from the coordinate conversion means. A drawing data generation means to be input; a display means for displaying the drawing data generated by the drawing data generation means; a MAX buffer in which the maximum value of the coordinates is stored; and the contents of the MAX buffer and the drawing data from the drawing data generation means. a first comparator that compares the drawing data to be applied to the display means and controls the sending of the drawing data applied to the display means from the drawing data generation means according to the comparison result; A second comparator that compares and updates the contents of the MAX buffer according to the comparison result, inputs two-dimensional coordinate data from the coordinate conversion means, and data from the MAX buffer, and draws the part where the line segment is hidden. The drawing data generated by the high-resolution drawing data generation means is applied to the display means according to the comparison result of the first comparator, and the line segment is A three-dimensional analytical diagram drawing device characterized in that it draws with high resolution parts that are hidden within minutes.