使用OpenGL绘制双3次B样条曲面的具体代码

以下是使用OpenGL绘制双3次B样条曲面的代码：

#include <GL/glut.h>
#include <vector>

using namespace std;

// 控制点
vector<vector<float>> controlPoints = {
    {-1.5, -1.5, 4.0},
    {-0.5, -1.5, 2.0},
    {0.5, -1.5, -1.0},
    {1.5, -1.5, 2.0},
    {-1.5, -0.5, 1.0},
    {-0.5, -0.5, 3.0},
    {0.5, -0.5, 0.0},
    {1.5, -0.5, -1.0},
    {-1.5, 0.5, 4.0},
    {-0.5, 0.5, 0.0},
    {0.5, 0.5, 3.0},
    {1.5, 0.5, 4.0},
    {-1.5, 1.5, -2.0},
    {-0.5, 1.5, -2.0},
    {0.5, 1.5, 0.0},
    {1.5, 1.5, -1.0}
};

// B样条基函数
float basis(int i, int k, float u, vector<float> knots) {
    if (k == 0) {
        if (u >= knots[i] && u < knots[i+1]) {
            return 1.0;
        } else {
            return 0.0;
        }
    } else {
        float a = (u - knots[i]) / (knots[i+k] - knots[i]);
        float b = (knots[i+k+1] - u) / (knots[i+k+1] - knots[i+1]);
        return a * basis(i, k-1, u, knots) + b * basis(i+1, k-1, u, knots);
    }
}

// 计算B样条曲面上的点
vector<float> calculatePoint(float u, float v, vector<float> uKnots, vector<float> vKnots) {
    vector<float> point(3, 0.0);
    for (int i = 0; i < 4; i++) {
        for (int j = 0; j < 4; j++) {
            float basisU = basis(i, 3, u, uKnots);
            float basisV = basis(j, 3, v, vKnots);
            point[0] += basisU * basisV * controlPoints[i*4+j][0];
            point[1] += basisU * basisV * controlPoints[i*4+j][1];
            point[2] += basisU * basisV * controlPoints[i*4+j][2];
        }
    }
    return point;
}

// 绘制B样条曲面
void drawBSplineSurface() {
    vector<float> uKnots = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
    vector<float> vKnots = {0.0, 0.0, 0.0, 0.0, 1.0, 1.0, 1.0, 1.0};
    glMap2f(GL_MAP2_VERTEX_3, 0.0, 1.0, 3, 4, 0.0, 1.0, 12, 4, &controlPoints[0][0]);
    glEnable(GL_MAP2_VERTEX_3);
    glEnable(GL_AUTO_NORMAL);
    glMapGrid2f(20, 0.0, 1.0, 20, 0.0, 1.0);
    glEvalMesh2(GL_FILL, 0, 20, 0, 20);
}

// 绘制函数
void display() {
    glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
    glPushMatrix();
    glRotatef(45.0, 1.0, 1.0, 1.0);
    drawBSplineSurface();
    glPopMatrix();
    glutSwapBuffers();
}

// 初始化函数
void init() {
    glClearColor(0.0, 0.0, 0.0, 0.0);
    glEnable(GL_DEPTH_TEST);
}

// 主函数
int main(int argc, char** argv) {
    glutInit(&argc, argv);
    glutInitDisplayMode(GLUT_DOUBLE | GLUT_RGB | GLUT_DEPTH);
    glutInitWindowSize(500, 500);
    glutCreateWindow("B-Spline Surface");
    init();
    glutDisplayFunc(display);
    glutMainLoop();
    return 0;
}

希望能够帮到你！