把一条直线扭成螺旋上升，再把得到的螺旋直线当做一条直线扭成螺旋上升如此无限循环.从而生成一种分形螺线.

核心代码:

1 void        CFractalHelix::FractalHelix(const Vector3& vStart, const Vector3& vEnd, Vector3* pVertices) 2 { 3     Vector3 vDir = vEnd - vStart; 4     float len = D3DXVec3Length(&vDir); 5     float radius = len*m_params[0]; 6  7     float xz = sqrtf(vDir.x*vDir.x + vDir.z*vDir.z); 8     float angleY = atan2f(xz, vDir.y); 9     float angleXZ = atan2f(vDir.x, vDir.z);10 11     float e = sin(angleY);12     float f = cos(angleY);13 14     float g = sin(angleXZ);15     float h = cos(angleXZ);16 17     for (int i = 0; i < CIRCLE_POINTS_COUNT; i++)18     {19         pVertices[i] = vStart + vDir*(i*1.0f/CIRCLE_POINTS_COUNT);20 21         float x0 = m_vSinCos[i].y;22         float y0 = - m_vSinCos[i].x*e;23         float z0 = + m_vSinCos[i].x*f;24 25         float x1 = x0*h + z0*g;26         float y1 = y0;27         float z1 = -x0*g + z0*h;28         29         pVertices[i].x += x1*radius;30         pVertices[i].y += y1*radius;31         pVertices[i].z += z1*radius;32     }33 }

代码写得有点让人头晕,其实就是将一根线段掰弯,生成若干表示曲线的线段,然后不停迭代.不过代码还有点瑕疵,有的线段接缝过度不太顺畅.

软件截图：