分形之螺線

把一條直線扭成螺旋上升，再把獲得的螺旋直線當作一條直線扭成螺旋上升如此無限循環.從而生成一種分形螺線.

核心代碼:

 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 }

代碼寫得有點讓人頭暈,其實就是將一根線段掰彎,生成若干表示曲線的線段,而後不停迭代.不過代碼還有點瑕疵,有的線段接縫過分不太順暢.

軟件截圖：