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  • 分形之树(Tree)

          似乎每一个有关分形的教程都要讲到分形树,大概是因为树是生活中最常见的分形实物吧。这一节将展示下如何一步一步地生长出一棵树来。其实现算法不难,就是在每一次生长迭代中,使线段生长出几条新的线段来。

    核心代码:

    static void FractalTree(const Vector3& vStart, const Vector3& vEnd, 
                            Yreal trunk_angle, Yreal branch_angle, Yreal trunk_c, Yreal branch_c, 
                            Vector3* pVertices)
    {
        Vector3 vSub = vEnd - vStart;
        Yreal len = D3DXVec3Length(&vSub);
        Yreal alfa = atan2f(vSub.y, vSub.x);
    
        Yreal trunk = len*trunk_c;
        Yreal branch = len*branch_c;
        Yreal branch2 = branch*1.25f;
    
        pVertices[0] = vEnd;
        //pVertices[1] = pVertices[0] + vSub*trunk_c;
        pVertices[1].x = pVertices[0].x + trunk*cosf(alfa + trunk_angle);
        pVertices[1].y = pVertices[0].y + trunk*sinf(alfa + trunk_angle);
        pVertices[1].z = 0.0f;
    
        pVertices[2] = vEnd;
        pVertices[3].x = pVertices[2].x + branch*cosf(alfa + branch_angle);
        pVertices[3].y = pVertices[2].y + branch*sinf(alfa + branch_angle);
        pVertices[3].z = 0.0f;
    
        pVertices[4] = pVertices[2];
        pVertices[5].x = pVertices[4].x + branch*cosf(alfa - branch_angle);
        pVertices[5].y = pVertices[4].y + branch*sinf(alfa - branch_angle);
        pVertices[5].z = 0.0f;
    
        pVertices[6] = vStart + vSub*0.55f;
        pVertices[7].x = pVertices[6].x + branch2*cosf(alfa + branch_angle);
        pVertices[7].y = pVertices[6].y + branch2*sinf(alfa + branch_angle);
        pVertices[7].z = 0.0f;
    
        pVertices[8] = pVertices[6];
        pVertices[9].x = pVertices[8].x + branch2*cosf(alfa - branch_angle);
        pVertices[9].y = pVertices[8].y + branch2*sinf(alfa - branch_angle);
        pVertices[9].z = 0.0f;
    }

    软件截图:

     

    树的生成需要若干个参数:树干的偏角,树枝的偏角,树干的生长长度,树枝的生长长度,修改下参数可以得到如下形状的树:

    软件下载地址:http://files.cnblogs.com/WhyEngine/Fractal.7z

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  • 原文地址:https://www.cnblogs.com/WhyEngine/p/4020532.html
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