要實(shí)現(xiàn)3D空間中的點(diǎn)坐標(biāo)轉(zhuǎn)換為屏幕二維點(diǎn)坐標(biāo)，需要進(jìn)行透視變換和投影變換。以下是一些基本的思路和示例代碼，可以用于實(shí)現(xiàn)主視圖、側(cè)視圖、俯視圖、正等軸投影。

1. 主視圖投影

主視圖投影是指以一個(gè)點(diǎn)作為視點(diǎn)，從一個(gè)方向觀察物體，投影到一個(gè)平面上。通常情況下，主視圖的觀察方向是從正面，也就是Z軸負(fù)方向。投影平面一般是平行于X-Y平面。

具體實(shí)現(xiàn)可以通過以下步驟完成：

• 定義觀察點(diǎn)坐標(biāo)和投影平面距離
• 對3D坐標(biāo)進(jìn)行透視變換
• 對透視變換后的坐標(biāo)進(jìn)行投影變換
• 將投影后的坐標(biāo)映射到屏幕上

示例代碼：

int x_2d = (int) (x_3d / (z_3d - view_point_z) * distance_to_projection_plane);
int y_2d = (int) (y_3d / (z_3d - view_point_z) * distance_to_projection_plane);

2. 側(cè)視圖投影

側(cè)視圖投影是指以一個(gè)點(diǎn)作為視點(diǎn)，從一個(gè)方向觀察物體，投影到一個(gè)平面上。通常情況下，側(cè)視圖的觀察方向是從側(cè)面，也就是X軸正方向。投影平面一般是平行于Y-Z平面。

具體實(shí)現(xiàn)可以通過以下步驟完成：

• 定義觀察點(diǎn)坐標(biāo)和投影平面距離
• 對3D坐標(biāo)進(jìn)行透視變換
• 對透視變換后的坐標(biāo)進(jìn)行投影變換
• 將投影后的坐標(biāo)映射到屏幕上

示例代碼：

int x_2d = (int) (y_3d / (x_3d - view_point_x) * distance_to_projection_plane);
int y_2d = (int) (z_3d / (x_3d - view_point_x) * distance_to_projection_plane);

3.?俯視圖投影

俯視圖投影是指以一個(gè)點(diǎn)作為視點(diǎn)，從一個(gè)方向觀察物體，投影到一個(gè)平面上。通常情況下，俯視圖的觀察方向是從上方，也就是Y軸正方向。投影平面一般是平行于X-Z平面。

具體實(shí)現(xiàn)可以通過以下步驟完成：

• 定義觀察點(diǎn)坐標(biāo)和投影平面距離
• 對3D坐標(biāo)進(jìn)行透視變換
• 對透視變換后的坐標(biāo)進(jìn)行投影變換
• 將投影后的坐標(biāo)映射到屏幕上

以下是一個(gè)簡單的示例代碼，用于將3D空間中的點(diǎn)坐標(biāo)轉(zhuǎn)化為屏幕二維點(diǎn)坐標(biāo)。這里包括了主視圖、側(cè)視圖、俯視圖、正等軸投影的實(shí)現(xiàn)。文章來源地址http://www.zghlxwxcb.cn/news/detail-757980.html

#include <stdio.h>
#include <stdlib.h>
#include <math.h>

#define SCREEN_WIDTH 640
#define SCREEN_HEIGHT 480

typedef struct {
    double x, y, z;
} Point3D;

typedef struct {
    int x, y;
} Point2D;

void project_ortho(Point3D point_3d, Point2D *point_2d, double distance_to_projection_plane) {
    point_2d->x = (int) point_3d.x;
    point_2d->y = (int) point_3d.y;
}

void project_isometric(Point3D point_3d, Point2D *point_2d, double distance_to_projection_plane) {
    point_2d->x = (int) ((point_3d.x - point_3d.z) * cos(30 * M_PI / 180));
    point_2d->y = (int) ((point_3d.y - (point_3d.x + point_3d.z) * sin(30 * M_PI / 180)) * cos(30 * M_PI / 180));
}

void project_main(Point3D point_3d, Point2D *point_2d, Point3D view_point, double distance_to_projection_plane) {
    double z_3d = point_3d.z - view_point.z;
    point_2d->x = (int) (point_3d.x - view_point.x) * distance_to_projection_plane / z_3d + SCREEN_WIDTH / 2;
    point_2d->y = (int) (point_3d.y - view_point.y) * distance_to_projection_plane / z_3d + SCREEN_HEIGHT / 2;
}

void project_side(Point3D point_3d, Point2D *point_2d, Point3D view_point, double distance_to_projection_plane) {
    double x_3d = point_3d.x - view_point.x;
    point_2d->x = (int) (point_3d.y - view_point.y) * distance_to_projection_plane / x_3d + SCREEN_WIDTH / 2;
    point_2d->y = (int) (point_3d.z - view_point.z) * distance_to_projection_plane / x_3d + SCREEN_HEIGHT / 2;
}

void project_top(Point3D point_3d, Point2D *point_2d, Point3D view_point, double distance_to_projection_plane) {
    double y_3d = point_3d.y - view_point.y;
    point_2d->x = (int) (point_3d.x - view_point.x) * distance_to_projection_plane / y_3d + SCREEN_WIDTH / 2;
    point_2d->y = (int) (point_3d.z - view_point.z) * distance_to_projection_plane / y_3d + SCREEN_HEIGHT / 2;
}

int main() {
    // Define the 3D points of a cube
    Point3D cube[8] = {
        {-50, -50, -50},
        {50, -50, -50},
        {50, 50, -50},
        {-50, 50, -50},
        {50, -50, 50},
        {50, 50, 50},
        {-50, 50, 50},
        {-50, -50, 50},
    };

    // Define the view point for the main, side, and top projections
    Point3D main_view_point = {0, 0, 200};
    Point3D side_view_point = {-200, 0, 0};
    Point3D top_view_point = {0, 200, 0};

    // Define the distance from the projection plane for the orthogonal and isometric projections
    double distance_to_ortho_projection_plane = 200;
    double distance_to_isometric_projection_plane = 200 / cos(30 * M_PI / 180);

    // Project the 3D points to 2D points for each projection
    Point2D main_projection[8];
    Point2D side_projection[8];
    Point2D top_projection[8];
    Point2D ortho_projection[8];
    Point2D iso_projection[8];

    int i;
    for (i = 0; i < 8; i++) {
        project_main(cube[i], &main_projection[i], main_view_point, distance_to_ortho_projection_plane);
        project_side(cube[i], &side_projection[i], side_view_point, distance_to_ortho_projection_plane);
        project_top(cube[i], &top_projection[i], top_view_point, distance_to_ortho_projection_plane);
        project_ortho(cube[i], &ortho_projection[i], distance_to_ortho_projection_plane);
        project_isometric(cube[i], &iso_projection[i], distance_to_isometric_projection_plane);
    }

    // Draw the 2D projections
    // ...
    // Your code to draw the projections goes here
    // ...

    return 0;
}

到了這里，關(guān)于用純C語言實(shí)現(xiàn)3D空間中的點(diǎn)坐標(biāo)轉(zhuǎn)化為屏幕二維點(diǎn)坐標(biāo)，包含主視圖、側(cè)視圖、俯視圖、正等軸投影的文章就介紹完了。如果您還想了解更多內(nèi)容，請?jiān)谟疑辖撬阉鱐OY模板網(wǎng)以前的文章或繼續(xù)瀏覽下面的相關(guān)文章，希望大家以后多多支持TOY模板網(wǎng)！