分形之螺线

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：