OpenGL绘制双三次B样条曲面代码
时间: 2023-04-03 09:01:53 浏览: 90
我可以回答这个问题。以下是OpenGL绘制双三次B样条曲面的代码示例:
```
GLfloat ctrlpoints[4][4][3] = {
{{-1.5, -1.5, 4.}, {-.5, -1.5, 2.}, {.5, -1.5, -1.}, {1.5, -1.5, 2.}},
{{-1.5, -.5, 1.}, {-.5, -.5, 3.}, {.5, -.5, .}, {1.5, -.5, -1.}},
{{-1.5, .5, 4.}, {-.5, .5, .}, {.5, .5, 3.}, {1.5, .5, 4.}},
{{-1.5, 1.5, -2.}, {-.5, 1.5, -2.}, {.5, 1.5, .}, {1.5, 1.5, -1.}}
};
glMap2f(GL_MAP2_VERTEX_3, , 1, 3, 4, , 1, 12, 4, &ctrlpoints[][][]);
glEnable(GL_MAP2_VERTEX_3);
glMapGrid2f(20, ., 1., 20, ., 1.);
glEvalMesh2(GL_FILL, , 20, , 20);
```
这段代码使用了OpenGL的双三次B样条曲面绘制功能,通过控制点数组`ctrlpoints`来定义曲面的形状。`glMap2f`函数将控制点数组映射到OpenGL的曲面绘制功能中,`glMapGrid2f`函数定义了曲面的细分网格,`glEvalMesh2`函数则根据细分网格和控制点数组来绘制曲面。
相关问题
opengl绘制双三次B样条曲面代码
我可以回答这个问题。以下是一个绘制双三次B样条曲面的OpenGL代码示例:
```
void drawBSplineSurface(float *ctrlPoints, int numU, int numV)
{
int u, v;
float uStep = 1.0f / (numU - 1);
float vStep = 1.0f / (numV - 1);
for (u = 0; u < numU - 3; u += 3)
{
for (v = 0; v < numV - 3; v += 3)
{
glBegin(GL_QUADS);
int i, j;
for (i = 0; i < 4; i++)
{
for (j = 0; j < 4; j++)
{
int index = ((u + i) * numV + (v + j)) * 3;
glVertex3f(ctrlPoints[index], ctrlPoints[index + 1], ctrlPoints[index + 2]);
}
}
glEnd();
}
}
}
```
这个函数接受一个控制点数组,以及曲面在u和v方向上的细分数。它使用OpenGL的四边形图元来绘制曲面。
opengl绘制B样条曲面代码
我可以回答这个问题。以下是一个简单的 OpenGL 绘制 B 样条曲面的代码示例:
```
#include <GL/glut.h>
GLfloat ctrlpoints[4][4][3] = {
{{-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}}
};
void display(void)
{
int i, j;
glClear(GL_COLOR_BUFFER_BIT | GL_DEPTH_BUFFER_BIT);
glColor3f(1.0, 1.0, 1.0);
glPushMatrix();
glRotatef(85.0, 1.0, 1.0, 1.0);
for (j = 0; j <= 8; j++) {
glBegin(GL_LINE_STRIP);
for (i = 0; i <= 30; i++)
glEvalCoord2f((GLfloat)i/30.0, (GLfloat)j/8.0);
glEnd();
glBegin(GL_LINE_STRIP);
for (i = 0; i <= 30; i++)
glEvalCoord2f((GLfloat)j/8.0, (GLfloat)i/30.0);
glEnd();
}
glPopMatrix();
glFlush();
}
void init(void)
{
glClearColor(0.0, 0.0, 0.0, 0.0);
glEnable(GL_DEPTH_TEST);
glMap2f(GL_MAP2_VERTEX_3, 0, 1, 3, 4, 0, 1, 12, 4, &ctrlpoints[0][0][0]);
glEnable(GL_MAP2_VERTEX_3);
glEnable(GL_AUTO_NORMAL);
glMapGrid2f(30, 0.0, 1.0, 30, 0.0, 1.0);
glEnable(GL_DEPTH_TEST);
glShadeModel(GL_FLAT);
}
void reshape(int w, int h)
{
glViewport(0, 0, (GLsizei) w, (GLsizei) h);
glMatrixMode(GL_PROJECTION);
glLoadIdentity();
if (w <= h)
glOrtho(-4.0, 4.0, -4.0*(GLfloat)h/(GLfloat)w,
4.0*(GLfloat)h/(GLfloat)w, -4.0, 4.0);
else
glOrtho(-4.0*(GLfloat)w/(GLfloat)h,
4.0*(GLfloat)w/(GLfloat)h, -4.0, 4.0, -4.0, 4.0);
glMatrixMode(GL_MODELVIEW);
glLoadIdentity();
}
int main(int argc, char** argv)
{
glutInit(&argc, argv);
glutInitDisplayMode(GLUT_SINGLE | GLUT_RGB | GLUT_DEPTH);
glutInitWindowSize(500, 500);
glutInitWindowPosition(100, 100);
glutCreateWindow(argv[0]);
init();
glutDisplayFunc(display);
glutReshapeFunc(reshape);
glutMainLoop();
return 0;
}
```