用c#代码绘制三维图形

在C#中，可以使用Windows Forms绘制三维图形。以下是一个简单的示例，展示如何使用C#和Windows Forms绘制一个立方体：

using System;
using System.Drawing;
using System.Windows.Forms;

namespace ThreeDGraphics
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Paint(object sender, PaintEventArgs e)
        {
            Graphics g = e.Graphics;
            Pen pen = new Pen(Color.Black);

            // 计算顶点坐标
            Point3D[] points = new Point3D[8];
            points[0] = new Point3D(-50, -50, -50);
            points[1] = new Point3D(-50, 50, -50);
            points[2] = new Point3D(50, 50, -50);
            points[3] = new Point3D(50, -50, -50);
            points[4] = new Point3D(-50, -50, 50);
            points[5] = new Point3D(-50, 50, 50);
            points[6] = new Point3D(50, 50, 50);
            points[7] = new Point3D(50, -50, 50);

            // 绘制立方体的六个面
            DrawQuad(points[0], points[1], points[2], points[3], g, pen);
            DrawQuad(points[1], points[5], points[6], points[2], g, pen);
            DrawQuad(points[5], points[4], points[7], points[6], g, pen);
            DrawQuad(points[4], points[0], points[3], points[7], g, pen);
            DrawQuad(points[0], points[4], points[5], points[1], g, pen);
            DrawQuad(points[3], points[2], points[6], points[7], g, pen);
        }

        private void DrawQuad(Point3D p1, Point3D p2, Point3D p3, Point3D p4, Graphics g, Pen pen)
        {
            Point[] pts = new Point[4];
            pts[0] = Project(p1);
            pts[1] = Project(p2);
            pts[2] = Project(p3);
            pts[3] = Project(p4);
            g.DrawPolygon(pen, pts);
        }

        private Point Project(Point3D p)
        {
            int x = (int)(p.X * 100 / (p.Z + 500));
            int y = (int)(p.Y * 100 / (p.Z + 500));
            return new Point(x + ClientSize.Width / 2, y + ClientSize.Height / 2);
        }
    }

    public class Point3D
    {
        public int X;
        public int Y;
        public int Z;

        public Point3D(int x, int y, int z)
        {
            X = x;
            Y = y;
            Z = z;
        }
    }
}

这个示例使用一个简单的透视投影算法，将三维坐标投射到屏幕上。在绘制立方体的每个面时，将其四个顶点的三维坐标投影到屏幕上，并使用绘图函数绘制多边形。