0，引入

“驭龙台”这个名字是后来起的，原本只是打算设计这么一个场景，如下图：

先申明一点：“驭龙台”场景中的大部分图形都是有磨边的楔形构成。

对于场景中的台阶、房顶、墙面，原本只是打算建差不多和上图中能看到的这么一个范围（对应phi0,phi1），后来把phi0、phi1扩充到了整个圆周。
所以，远看这个场景是这么个样子：

从这个视角看时，咱就决定将这个场景命名为“驭龙台”啦！
至于为什么起这个名？这个名的含义是什么？
木有深究，只是感觉很厉害的样子！！！

接下来，我们将分别看看场景中的各个部分是怎么设置和创建的。
主要是要注意：各个“基本图形”的参数设置，以便和谐地构成整个场景。

1，第一部分：中间的圆台

这一部分又是有三部分组成：最下面的Rosette花环、磨边的box、矩形面。

1.1 Rossette花环

这个和“Q104：怎么用ray tracing画基于磨边楔形的“花环（Rosette）””是一样的。之前的链接：
http://blog.csdn.net/libing_zeng/article/details/70194670

Phong材质，大理石纹理。

场景中创建这么一个设置有随机大理石纹理的Rosette的相关代码如下：

////////////////////////////////////////floor, Rosette///////////////////////////////////////// rosette parametersint     num_rings = 3;      // maximum of 6float   hole_radius = 1.0;float   ring_width = 1.0;float   rb = 0.025;         // bevel radiusfloat   y0 = -0.1;          // minimum y valuefloat   y1 = 0.1;           // minimum y valueRosette* rosette_floor_ptr = new Rosette(num_rings, hole_radius, ring_width, rb, y0, y1);// put a different random marble texture on each wedge// ramp image:Image* image_floor_ptr = new Image;image_floor_ptr->read_ppm_file(".\\TextureFiles\\ppm\\BlueMarbleRamp.ppm");// marble texture parametersint floor_num_octaves = 4;float floor_lacunarity = 2.0;float floor_gain = 0.5;float floor_perturbation = 3.0;int floor_num_objects = rosette_floor_ptr->get_num_objects();for (int j = 0; j < floor_num_objects; j++) {// noise:CubicNoise* noise_floor_ptr = new CubicNoise;noise_floor_ptr->set_num_octaves(floor_num_octaves);noise_floor_ptr->set_gain(floor_gain);          // not relevant when num_octaves = 1noise_floor_ptr->set_lacunarity(floor_lacunarity);     // not relevant when num_octaves = 1// marble texture:FBmTextureRamp* marble_floor_ptr = new FBmTextureRamp(image_floor_ptr);marble_floor_ptr->set_noise(noise_floor_ptr);marble_floor_ptr->set_perturbation(floor_perturbation);// transformed marble textureInstanceTexture* wedge_marble_floor_ptr = new InstanceTexture(marble_floor_ptr);set_rand_seed(j * 10);wedge_marble_floor_ptr->scale(0.25);wedge_marble_floor_ptr->rotate_x(20.0 * (2.0 * rand_float() - 1.0));wedge_marble_floor_ptr->rotate_y(30.0 * (2.0 * rand_float() - 1.0));wedge_marble_floor_ptr->rotate_z(45.0 * (2.0 * rand_float() - 1.0));wedge_marble_floor_ptr->translate(10.0 * (2.0 * rand_float() - 1.0), 20.0 * (2.0 * rand_float() - 1.0), 30.0 * (2.0 * rand_float() - 1.0));// material:SV_Phong* sv_phong_floor_ptr = new SV_Phong;sv_phong_floor_ptr->set_ka(0.25);sv_phong_floor_ptr->set_kd(0.75);sv_phong_floor_ptr->set_cd(wedge_marble_floor_ptr);sv_phong_floor_ptr->set_ks(0.1);sv_phong_floor_ptr->set_exp(20.0);rosette_floor_ptr->store_material(sv_phong_floor_ptr, j);   // store material in the specified wedge}rosette_floor_ptr->setup_cells();add_object(rosette_floor_ptr);

1.2 磨边的box

花环floor之上是四个磨边的box组成的封闭框架。

Phong材质，4号砂岩纹理。

创建这么四个磨边的box的相关代码如下：

// noise:CubicNoise* noise_bevel_b_platform_ptr = new CubicNoise;noise_bevel_b_platform_ptr->set_num_octaves(6);noise_bevel_b_platform_ptr->set_gain(2);            // not relevant when num_octaves = 1noise_bevel_b_platform_ptr->set_lacunarity(0.5);     // not relevant when num_octaves = 1// ramp image:Image* image_bevel_b_platform_ptr = new Image;image_bevel_b_platform_ptr->read_ppm_file(".\\TextureFiles\\ppm\\sandstone_ramp4.ppm");// marble texture:FBmTextureRamp* sandstone_bevel_b_platform_ptr = new FBmTextureRamp(image_bevel_b_platform_ptr);sandstone_bevel_b_platform_ptr->set_noise(noise_bevel_b_platform_ptr);sandstone_bevel_b_platform_ptr->set_perturbation(0.1);// transformed sandstone textureInstanceTexture* wedge_sandstone_bevel_b_platform_ptr = new InstanceTexture(sandstone_bevel_b_platform_ptr);set_rand_seed(20);wedge_sandstone_bevel_b_platform_ptr->scale(0.25);wedge_sandstone_bevel_b_platform_ptr->rotate_x(20.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_bevel_b_platform_ptr->rotate_y(30.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_bevel_b_platform_ptr->rotate_z(45.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_bevel_b_platform_ptr->translate(10.0 * (2.0 * rand_float() - 1.0), 20.0 * (2.0 * rand_float() - 1.0), 30.0 * (2.0 * rand_float() - 1.0));// material:SV_Phong* sv_phong_bevel_b_platform_ptr = new SV_Phong;sv_phong_bevel_b_platform_ptr->set_ka(0.25);sv_phong_bevel_b_platform_ptr->set_kd(0.75);sv_phong_bevel_b_platform_ptr->set_cd(wedge_sandstone_bevel_b_platform_ptr);sv_phong_bevel_b_platform_ptr->set_ks(0.1);sv_phong_bevel_b_platform_ptr->set_exp(20.0);BeveledBox* bevel_b_platform_ptr1 = new BeveledBox(Point3D(-2.9, 0.1,-1.9), Point3D(-2.7, 0.3,  1.9), 0.1);bevel_b_platform_ptr1->set_material(sv_phong_bevel_b_platform_ptr);add_object(bevel_b_platform_ptr1);BeveledBox* bevel_b_platform_ptr2 = new BeveledBox(Point3D( 2.7, 0.1,-1.9), Point3D( 2.9, 0.3,  1.9), 0.1);bevel_b_platform_ptr2->set_material(sv_phong_bevel_b_platform_ptr);add_object(bevel_b_platform_ptr2);BeveledBox* bevel_b_platform_ptr3 = new BeveledBox(Point3D(-2.7, 0.1, 1.7), Point3D( 2.7, 0.3,  1.9), 0.1);bevel_b_platform_ptr3->set_material(sv_phong_bevel_b_platform_ptr);add_object(bevel_b_platform_ptr3);BeveledBox* bevel_b_platform_ptr4 = new BeveledBox(Point3D(-2.7, 0.1,-1.9), Point3D( 2.7, 0.3, -1.7), 0.1);bevel_b_platform_ptr4->set_material(sv_phong_bevel_b_platform_ptr);add_object(bevel_b_platform_ptr4);

这里需要注意的是：用于创建BeveledBox对象的两个顶点（第一个顶点是“最小顶点”，第二个顶点是“最大顶点”。第一个顶点的三个坐标值必须都比第三个顶点坐标的三个值药效。）

1.3 矩形

四个磨边的box组成的封闭框架中间嵌这一个矩形面。类似于“镶着边框的镜子”

glossy材质，wrapped的噪声纹理。
glossy的指数为1000，矩形面中的镜像比较模糊。

创建矩形的相关代码如下：

    Rectangle* rectangle_platform_ptr = new Rectangle(Point3D(-2.7, 0.2, 1.7), Vector3D(5.4, 0, 0), Vector3D(0, 0, -3.4));// noise:CubicNoise* noise_rectangle_platform_ptr = new CubicNoise;noise_rectangle_platform_ptr->set_num_octaves(8);noise_rectangle_platform_ptr->set_gain(0.5);noise_rectangle_platform_ptr->set_lacunarity(8.0);FBmTextureWrapped* texture_rectangle_platform_ptr = new FBmTextureWrapped(noise_rectangle_platform_ptr);texture_rectangle_platform_ptr->set_expansion_number(8.0);texture_rectangle_platform_ptr->set_color(0.7, 1.0, 0.5);   // light greentexture_rectangle_platform_ptr->set_min_value(0.0);texture_rectangle_platform_ptr->set_max_value(1.0);// textured material:float exp_rectangle_platform = 1000.0;SV_GlossyReflector* sv_glossy_rectangle_platform_ptr = new SV_GlossyReflector;sv_glossy_rectangle_platform_ptr->set_samples(num_samples, exp_rectangle_platform);sv_glossy_rectangle_platform_ptr->set_ka(0.1);sv_glossy_rectangle_platform_ptr->set_kd(0.25);sv_glossy_rectangle_platform_ptr->set_ks(0.1);sv_glossy_rectangle_platform_ptr->set_exp(exp_rectangle_platform);sv_glossy_rectangle_platform_ptr->set_cd(texture_rectangle_platform_ptr);sv_glossy_rectangle_platform_ptr->set_kr(0.75);sv_glossy_rectangle_platform_ptr->set_exponent(exp_rectangle_platform);sv_glossy_rectangle_platform_ptr->set_cr(new ConstantColor(white));Instance* instance_sc_rectangle_platform_ptr = new Instance(rectangle_platform_ptr);instance_sc_rectangle_platform_ptr->set_material(sv_glossy_rectangle_platform_ptr);add_object(instance_sc_rectangle_platform_ptr);

2，第二部分：龙

“龙”卧在在矩形面上。

Phong材质，大理石纹理。

“龙”模型的创建和“Q102：光线追踪场景（2）——PLYs（多种模型汇集）”是一样的。之前的链接如下：
http://blog.csdn.net/libing_zeng/article/details/70176906

创建“龙”模型的相关代码如下：

////////////////////////////////////////dragon////////////////////////////////////////////////char* file_dragon_name = ".\\PLYFiles\\dragon.ply";Grid* grid_dragon_ptr = new Grid(new Mesh);grid_dragon_ptr->read_smooth_triangles(file_dragon_name);grid_dragon_ptr->setup_cells();// noise:CubicNoise* noise_dragon_ptr = new CubicNoise;noise_dragon_ptr->set_num_octaves(6);noise_dragon_ptr->set_gain(0.5);noise_dragon_ptr->set_lacunarity(2.0);// ramp image:Image* image_dragon_ptr = new Image;image_dragon_ptr->read_ppm_file(".\\TextureFiles\\ppm\\BlueMarbleRamp.ppm");// marble texture:FBmTextureRamp* marble_dragon_ptr = new FBmTextureRamp(image_dragon_ptr);marble_dragon_ptr->set_noise(noise_dragon_ptr);marble_dragon_ptr->set_perturbation(4.0);InstanceTexture* it_dragon_ptr = new InstanceTexture(marble_dragon_ptr);it_dragon_ptr->scale(0.05);
//  it_dragon_ptr->rotate_z(110);
//  it_dragon_ptr->translate(1.0, 4.0, 0.0);// material:SV_Phong* sv_phong_dragon_ptr = new SV_Phong;sv_phong_dragon_ptr->set_ka(0.25);sv_phong_dragon_ptr->set_kd(0.75);sv_phong_dragon_ptr->set_cd(it_dragon_ptr);sv_phong_dragon_ptr->set_ks(0.1);sv_phong_dragon_ptr->set_exp(20.0);Instance* instance_dragon_ptr = new Instance(grid_dragon_ptr);instance_dragon_ptr->scale(20, 10, 20);instance_dragon_ptr->translate(0, -0.3, 0);instance_dragon_ptr->set_material(sv_phong_dragon_ptr);add_object(instance_dragon_ptr);

3，第三部分：柱子（pillars）

“柱子”是由若干个“Rosette”叠加而成的。
Phong材质，3号砂岩纹理

相关参数：
柱子底的位置y0_p、柱子顶的位置y1_p、组成柱子的Rosette的个数rosette_num_pillar、磨边Rosette的三个参数（hole_radius_p、 ring_width_p、rb_p）、场景中柱子的根数pillar_num、所有柱子的起始角度和终止角度（pillar_angle_start、pillar_angle_end）。

由如上参数，我们可以计算：
1，两根柱子间的角度范围pillar_angle_width = (pillar_angle_end - pillar_angle_start) / pillar_num；
2，单个Rosette的高度rosette_height = (y1_p - y0_p) / rosette_num_pillar；
3，第pi跟柱子对应的角度phi0_pillar = (pillar_angle_start + pillar_angle_width * pi) * PI_ON_180；
从而，可以计算得到每根柱子位置的x、z坐标：
pillar_center_x = - (hole_radius_p + ring_width_p + r0_s) * sin((phi0_pillar-1e-6));
pillar_center_z = (hole_radius_p + ring_width_p + r0_s) * cos((phi0_pillar-1e-6));
4，单根柱子中第ri个Rosette的上下底的位置：
rosette_y0_temp = y0_p + ri*rosette_height;
rosette_y1_temp = rosette_y0_temp + rosette_height;
这样创建Rosette对象所需的参数就齐啦。

（3、4中对应两个for循环：3中根据柱子编号pi循环；4中根据单个柱子中Rosette的编号循环）。

创建“柱子”的相关代码如下：（随机砂岩纹理的设置和Rosette中随机大理石纹理的设置相似）

////////////////////////////////////////pillar, Rosette///////////////////////////////////////// rosette parametersint     num_rings_p = 1;        // maximum of 6float   hole_radius_p = 0.05;float   ring_width_p = 0.25;float   rb_p = 0.02;            // bevel radiusfloat   y0_p = 0.3;         // minimum y valuefloat   y1_p = 3.7;         // minimum y valueint pillar_num = 4;double pillar_angle_start = -45;double pillar_angle_end = 315;double pillar_angle_width = (pillar_angle_end - pillar_angle_start) / pillar_num;int rosette_num_pillar = 20;double rosette_height = (y1_p - y0_p) / rosette_num_pillar;for (int pi=0; pi<=pillar_num; pi++) {double phi0_pillar = (pillar_angle_start + pillar_angle_width * pi) * PI_ON_180;double pillar_center_x = - (hole_radius_p + ring_width_p + r0_s) * sin((phi0_pillar-1e-6));double pillar_center_z =   (hole_radius_p + ring_width_p + r0_s) * cos((phi0_pillar-1e-6));for (int ri=0; ri<rosette_num_pillar; ri++) {double rosette_y0_temp = y0_p + ri*rosette_height;double rosette_y1_temp = rosette_y0_temp + rosette_height;Rosette* rosette_pillar_ptr = new Rosette(num_rings_p, hole_radius_p, ring_width_p, rb_p, rosette_y0_temp, rosette_y1_temp);// put a different random marble texture on each wedge// ramp image:Image* image_rp_ptr = new Image;image_rp_ptr->read_ppm_file(".\\TextureFiles\\ppm\\sandstone_ramp3.ppm");// marble texture parametersint num_octaves_rp = 4;float lacunarity_rp = 2.0;float gain_rp = 0.5;float perturbation_rp = 0.1;int num_objects_rp = rosette_pillar_ptr->get_num_objects();for (int rpj = 0; rpj < num_objects_rp; rpj++) {// noise:CubicNoise* noise_rp_ptr = new CubicNoise;noise_rp_ptr->set_num_octaves(num_octaves_rp);noise_rp_ptr->set_gain(gain_rp);            // not relevant when num_octaves = 1noise_rp_ptr->set_lacunarity(lacunarity_rp);     // not relevant when num_octaves = 1// marble texture:FBmTextureRamp* sandstone_rp_ptr = new FBmTextureRamp(image_rp_ptr);sandstone_rp_ptr->set_noise(noise_rp_ptr);sandstone_rp_ptr->set_perturbation(perturbation_rp);// transformed marble textureInstanceTexture* wedge_sandstone_rp_ptr = new InstanceTexture(sandstone_rp_ptr);set_rand_seed(rpj * 10);wedge_sandstone_rp_ptr->scale(0.25);wedge_sandstone_rp_ptr->rotate_x(20.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_rp_ptr->rotate_y(30.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_rp_ptr->rotate_z(45.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_rp_ptr->translate(10.0 * (2.0 * rand_float() - 1.0), 20.0 * (2.0 * rand_float() - 1.0), 30.0 * (2.0 * rand_float() - 1.0));// material:SV_Phong* sv_phong_rp_ptr = new SV_Phong;sv_phong_rp_ptr->set_ka(0.25);sv_phong_rp_ptr->set_kd(0.75);sv_phong_rp_ptr->set_cd(wedge_sandstone_rp_ptr);sv_phong_rp_ptr->set_ks(0.1);sv_phong_rp_ptr->set_exp(20.0);rosette_pillar_ptr->store_material(sv_phong_rp_ptr, rpj);   // store material in the specified wedge}rosette_pillar_ptr->setup_cells();Instance* instance_rp_ptr = new Instance(rosette_pillar_ptr);instance_rp_ptr->translate(pillar_center_x, 0, pillar_center_z);add_object(instance_rp_ptr);}}

4，第四部分：门

整个墙面就是由若干个这样的门拼接而成。

如上图，每一扇门是由很多个“基本部分”组成。
每一个“基本部分”都是一个“磨边的楔形（Beveled Wedge）”。
只是每个磨边楔形的形状、大小、材质、纹理不一样。

每一扇门被称为一个“unit”。假设每个unit为5个单位长度，那么设置该unit中每个wedge的相关参数如下：

    double _wall_width      = 0.5;double _frame_width     = 0.1;double _window_width    = 0.8;double _door_width      = 0.95;double _gap_width       = 0.1;double unit             = 5.0; // (wall+frame+window+frame+door)*2+gapdouble _wall_width_rate     = _wall_width    / unit;double _frame_width_rate    = _frame_width   / unit;double _window_width_rate   = _window_width  / unit;double _door_width_rate     = _door_width    / unit;double _gap_width_rate      = _gap_width     / unit;int unit_num = 10;double angle_start = 0; // -90,270double angle_end = 360;double unit_angle_width = (angle_end - angle_start) / unit_num;double _wall_angle_width    = _wall_width_rate      * unit_angle_width;double _frame_angle_width   = _frame_width_rate     * unit_angle_width;double _window_angle_width  = _window_width_rate    * unit_angle_width;double _door_angle_width    = _door_width_rate      * unit_angle_width;double _gap_angle_width     = _gap_width_rate       * unit_angle_width;double y10_unit = 0.3;          // bottom of the unitdouble y11_unit = 3.7;          // top of the unitdouble y20_unit = 0.3;          // the height of frame is 0.1double y21_unit = 0.4;double y30_unit = 0.4;          // the height of window is 1double y31_unit = 1.4;double y40_unit = 1.4;double y41_unit = 1.5;double y50_unit = 1.5;double y51_unit = 2.5;double y60_unit = 2.5;double y61_unit = 2.6;double y70_unit = 2.6;double y71_unit = 3.6;double y80_unit = 3.6;double y81_unit = 3.7;double r10_unit = 6.9;          // inner radius for phong material objects: wall, framedouble r11_unit = 7.0;          // outer radius for phong material objects: wall, framedouble r20_unit = 6.94;         // inner radius for glossy material objects: door, windowdouble r21_unit = 6.96;         // outer radius for glossy material objects: door, windowdouble rb1_unit  = 0.01;        // beveled radius for phong material objectsdouble rb2_unit  = 0.005;       // beveled radius for glossy material objects

前面已经提到过，每个unit中涉及到各种材质和纹理：
墙面：Phong材质，1号砂岩纹理；
纵向门框：Phong材质，纵向木纹纹理；
横向门框：Phong材质，横向木纹纹理；
门体、窗户：glossy材质（指数设置为100000），无纹理；

相关代码如下：


//---------------------------------------------wall material-----------------------------------// noise:CubicNoise* noise_wall_ptr1 = new CubicNoise;noise_wall_ptr1->set_num_octaves(6);noise_wall_ptr1->set_gain(0.5);         // not relevant when num_octaves = 1noise_wall_ptr1->set_lacunarity(2.0);     // not relevant when num_octaves = 1// ramp image:Image* image_wall_ptr1 = new Image;
//    image_wall_ptr1->read_ppm_file(".\\TextureFiles\\ppm\\BlueMarbleRamp.ppm");image_wall_ptr1->read_ppm_file(".\\TextureFiles\\ppm\\sandstone_ramp1.ppm");// marble texture:FBmTextureRamp* marble_wall_ptr1 = new FBmTextureRamp(image_wall_ptr1);marble_wall_ptr1->set_noise(noise_wall_ptr1);marble_wall_ptr1->set_perturbation(0.2);InstanceTexture* it_wall_ptr1 = new InstanceTexture(marble_wall_ptr1);it_wall_ptr1->scale(0.5);it_wall_ptr1->rotate_z(110);it_wall_ptr1->translate(1.0, 4.0, 0.0);// material:SV_Phong* sv_phong_wall_ptr1 = new SV_Phong;sv_phong_wall_ptr1->set_ka(0.25);sv_phong_wall_ptr1->set_kd(0.75);sv_phong_wall_ptr1->set_cd(it_wall_ptr1);sv_phong_wall_ptr1->set_ks(0.1);sv_phong_wall_ptr1->set_exp(20.0);//---------------------------------------------vertical frame material-----------------------------------// wood textureRGBColor frame_light_color1(0.8274, 0.5059, 0.2392);RGBColor frame_dark_color1(0.05);Wood* wood_frame_ptr1 = new Wood(frame_light_color1, frame_dark_color1);wood_frame_ptr1->set_grainy(1.0);wood_frame_ptr1->set_ringy(1.0);InstanceTexture* transformed_wood_frame_ptr1 = new InstanceTexture(wood_frame_ptr1);set_rand_seed(40);transformed_wood_frame_ptr1->scale(0.4);transformed_wood_frame_ptr1->rotate_x(20.0 * (2.0 * rand_float() - 1.0));transformed_wood_frame_ptr1->rotate_y(30.0 * (2.0 * rand_float() - 1.0));transformed_wood_frame_ptr1->rotate_z(45.0 * (2.0 * rand_float() - 1.0));// material:SV_Phong* sv_phong_frame_ptr1 = new SV_Phong;sv_phong_frame_ptr1->set_ka(0.25);sv_phong_frame_ptr1->set_kd(0.75);sv_phong_frame_ptr1->set_cd(transformed_wood_frame_ptr1);sv_phong_frame_ptr1->set_ks(0.1);sv_phong_frame_ptr1->set_exp(20.0);//---------------------------------------------horizontal frame material-----------------------------------// wood textureRGBColor frame_light_color2(0.8274, 0.5059, 0.2392);RGBColor frame_dark_color2(0.05);Wood* wood_frame_ptr2 = new Wood(frame_light_color2, frame_dark_color2);wood_frame_ptr2->set_grainy(1.0);wood_frame_ptr2->set_ringy(1.0);InstanceTexture* transformed_wood_frame_ptr2 = new InstanceTexture(wood_frame_ptr2);set_rand_seed(80);transformed_wood_frame_ptr2->scale(0.8);transformed_wood_frame_ptr2->rotate_x(20.0 * (2.0 * rand_float() - 1.0));transformed_wood_frame_ptr2->rotate_y(30.0 * (2.0 * rand_float() - 1.0));transformed_wood_frame_ptr2->rotate_z(45.0 * (2.0 * rand_float() - 1.0));// material:SV_Phong* sv_phong_frame_ptr2 = new SV_Phong;sv_phong_frame_ptr2->set_ka(0.25);sv_phong_frame_ptr2->set_kd(0.75);sv_phong_frame_ptr2->set_cd(transformed_wood_frame_ptr2);sv_phong_frame_ptr2->set_ks(0.1);sv_phong_frame_ptr2->set_exp(20.0);//---------------------------------------------window material-----------------------------------// textured material:float exp_window = 100000.0; // 10000SV_GlossyReflector* sv_glossy_window_ptr = new SV_GlossyReflector;sv_glossy_window_ptr->set_samples(num_samples, exp_window);sv_glossy_window_ptr->set_ka(0.1);sv_glossy_window_ptr->set_kd(0.25);sv_glossy_window_ptr->set_ks(0.1);sv_glossy_window_ptr->set_exp(exp_window);sv_glossy_window_ptr->set_cd(new ConstantColor(RGBColor(0.5)));sv_glossy_window_ptr->set_kr(0.75);sv_glossy_window_ptr->set_exponent(exp_window);sv_glossy_window_ptr->set_cr(new ConstantColor(white));

接下来就是：
几何构建整个unit；
设置相应的材质和纹理。

for (int ui=0; ui<unit_num; ui++) {double phi0_unit = angle_start + unit_angle_width * ui;double phi1_unit = angle_start + unit_angle_width * (ui+1);double phi0_wall1 = phi0_unit;double phi1_wall1 = phi0_wall1 + _wall_angle_width;BeveledWedge* wedge_wall_ptr1 = new BeveledWedge(y10_unit, y11_unit, r10_unit, r11_unit, rb1_unit, phi0_wall1 , phi1_wall1);wedge_wall_ptr1->set_material(sv_phong_wall_ptr1);add_object(wedge_wall_ptr1);double phi0_frame11 = phi1_wall1;double phi1_frame11 = phi1_wall1 + _frame_angle_width;BeveledWedge* wedge_frame11_ptr = new BeveledWedge(y10_unit, y11_unit, r10_unit, r11_unit, rb1_unit, phi0_frame11 , phi1_frame11);wedge_frame11_ptr->set_material(sv_phong_frame_ptr1);add_object(wedge_frame11_ptr);double phi0_frame21 = phi1_frame11;double phi1_frame21 = phi0_frame21 + _window_angle_width;BeveledWedge* wedge_frame21_ptr1 = new BeveledWedge(y20_unit, y21_unit, r10_unit, r11_unit, rb1_unit, phi0_frame21 , phi1_frame21);wedge_frame21_ptr1->set_material(sv_phong_frame_ptr2);add_object(wedge_frame21_ptr1);BeveledWedge* wedge_frame21_ptr2 = new BeveledWedge(y40_unit, y41_unit, r10_unit, r11_unit, rb1_unit, phi0_frame21 , phi1_frame21);wedge_frame21_ptr2->set_material(sv_phong_frame_ptr2);add_object(wedge_frame21_ptr2);BeveledWedge* wedge_frame21_ptr3 = new BeveledWedge(y60_unit, y61_unit, r10_unit, r11_unit, rb1_unit, phi0_frame21 , phi1_frame21);wedge_frame21_ptr3->set_material(sv_phong_frame_ptr2);add_object(wedge_frame21_ptr3);BeveledWedge* wedge_frame21_ptr4 = new BeveledWedge(y80_unit, y81_unit, r10_unit, r11_unit, rb1_unit, phi0_frame21 , phi1_frame21);wedge_frame21_ptr4->set_material(sv_phong_frame_ptr2);add_object(wedge_frame21_ptr4);BeveledWedge* wedge_window_ptr1 = new BeveledWedge(y30_unit, y31_unit, r20_unit, r21_unit, rb2_unit, phi0_frame21 , phi1_frame21);wedge_window_ptr1->set_material(sv_glossy_window_ptr);add_object(wedge_window_ptr1);BeveledWedge* wedge_window_ptr2 = new BeveledWedge(y50_unit, y51_unit, r20_unit, r21_unit, rb2_unit, phi0_frame21 , phi1_frame21);wedge_window_ptr2->set_material(sv_glossy_window_ptr);add_object(wedge_window_ptr2);BeveledWedge* wedge_window_ptr3 = new BeveledWedge(y70_unit, y71_unit, r20_unit, r21_unit, rb2_unit, phi0_frame21 , phi1_frame21);wedge_window_ptr3->set_material(sv_glossy_window_ptr);add_object(wedge_window_ptr3);double phi0_frame12 = phi1_frame21;double phi1_frame12 = phi0_frame12 + _frame_angle_width;BeveledWedge* wedge_frame12_ptr = new BeveledWedge(y10_unit, y11_unit, r10_unit, r11_unit, rb1_unit, phi0_frame12 , phi1_frame12);wedge_frame12_ptr->set_material(sv_phong_frame_ptr1);add_object(wedge_frame12_ptr);double phi0_frame22 = phi1_frame12;double phi1_frame22 = phi0_frame22 + _door_angle_width;BeveledWedge* wedge_frame22_ptr1 = new BeveledWedge(y20_unit, y21_unit, r10_unit, r11_unit, rb1_unit, phi0_frame22 , phi1_frame22);wedge_frame22_ptr1->set_material(sv_phong_frame_ptr2);add_object(wedge_frame22_ptr1);BeveledWedge* wedge_frame22_ptr2 = new BeveledWedge(y60_unit, y61_unit, r10_unit, r11_unit, rb1_unit, phi0_frame22 , phi1_frame22);wedge_frame22_ptr2->set_material(sv_phong_frame_ptr2);add_object(wedge_frame22_ptr2);BeveledWedge* wedge_frame22_ptr3 = new BeveledWedge(y80_unit, y81_unit, r10_unit, r11_unit, rb1_unit, phi0_frame22 , phi1_frame22);wedge_frame22_ptr3->set_material(sv_phong_frame_ptr2);add_object(wedge_frame22_ptr3);BeveledWedge* wedge_door_ptr1 = new BeveledWedge(y30_unit, y51_unit, r20_unit, r21_unit, rb2_unit, phi0_frame22 , phi1_frame22);wedge_door_ptr1->set_material(sv_glossy_window_ptr);add_object(wedge_door_ptr1);BeveledWedge* wedge_window2_ptr1 = new BeveledWedge(y70_unit, y71_unit, r20_unit, r21_unit, rb2_unit, phi0_frame22 , phi1_frame22);wedge_window2_ptr1->set_material(sv_glossy_window_ptr);add_object(wedge_window2_ptr1);double phi0_frame13 = phi1_frame22;double phi1_frame13 = phi0_frame13 + _gap_angle_width;BeveledWedge* wedge_frame13_ptr = new BeveledWedge(y60_unit, y81_unit, r10_unit, r11_unit, rb1_unit, phi0_frame13 , phi1_frame13);wedge_frame13_ptr->set_material(sv_phong_frame_ptr1);add_object(wedge_frame13_ptr);double phi0_frame23 = phi1_frame13;double phi1_frame23 = phi0_frame23 + _door_angle_width;BeveledWedge* wedge_frame23_ptr1 = new BeveledWedge(y20_unit, y21_unit, r10_unit, r11_unit, rb1_unit, phi0_frame23 , phi1_frame23);wedge_frame23_ptr1->set_material(sv_phong_frame_ptr2);add_object(wedge_frame23_ptr1);BeveledWedge* wedge_frame23_ptr2 = new BeveledWedge(y60_unit, y61_unit, r10_unit, r11_unit, rb1_unit, phi0_frame23 , phi1_frame23);wedge_frame23_ptr2->set_material(sv_phong_frame_ptr2);add_object(wedge_frame23_ptr2);BeveledWedge* wedge_frame23_ptr3 = new BeveledWedge(y80_unit, y81_unit, r10_unit, r11_unit, rb1_unit, phi0_frame23 , phi1_frame23);wedge_frame23_ptr3->set_material(sv_phong_frame_ptr2);add_object(wedge_frame23_ptr3);BeveledWedge* wedge_door_ptr2 = new BeveledWedge(y30_unit, y51_unit, r20_unit, r21_unit, rb2_unit, phi0_frame23 , phi1_frame23);wedge_door_ptr2->set_material(sv_glossy_window_ptr);add_object(wedge_door_ptr2);BeveledWedge* wedge_window3_ptr1 = new BeveledWedge(y70_unit, y71_unit, r20_unit, r21_unit, rb2_unit, phi0_frame23 , phi1_frame23);wedge_window3_ptr1->set_material(sv_glossy_window_ptr);add_object(wedge_window3_ptr1);double phi0_frame14 = phi1_frame23;double phi1_frame14 = phi0_frame14 + _frame_angle_width;BeveledWedge* wedge_frame14_ptr = new BeveledWedge(y10_unit, y11_unit, r10_unit, r11_unit, rb1_unit, phi0_frame14 , phi1_frame14);wedge_frame14_ptr->set_material(sv_phong_frame_ptr1);add_object(wedge_frame14_ptr);double phi0_frame24 = phi1_frame14;double phi1_frame24 = phi0_frame24 + _window_angle_width;BeveledWedge* wedge_frame24_ptr1 = new BeveledWedge(y20_unit, y21_unit, r10_unit, r11_unit, rb1_unit, phi0_frame24 , phi1_frame24);wedge_frame24_ptr1->set_material(sv_phong_frame_ptr2);add_object(wedge_frame24_ptr1);BeveledWedge* wedge_frame24_ptr2 = new BeveledWedge(y40_unit, y41_unit, r10_unit, r11_unit, rb1_unit, phi0_frame24 , phi1_frame24);wedge_frame24_ptr2->set_material(sv_phong_frame_ptr2);add_object(wedge_frame24_ptr2);BeveledWedge* wedge_frame24_ptr3 = new BeveledWedge(y60_unit, y61_unit, r10_unit, r11_unit, rb1_unit, phi0_frame24 , phi1_frame24);wedge_frame24_ptr3->set_material(sv_phong_frame_ptr2);add_object(wedge_frame24_ptr3);BeveledWedge* wedge_frame24_ptr4 = new BeveledWedge(y80_unit, y81_unit, r10_unit, r11_unit, rb1_unit, phi0_frame24 , phi1_frame24);wedge_frame24_ptr4->set_material(sv_phong_frame_ptr2);add_object(wedge_frame24_ptr4);BeveledWedge* wedge_window4_ptr1 = new BeveledWedge(y30_unit, y31_unit, r20_unit, r21_unit, rb2_unit, phi0_frame24 , phi1_frame24);wedge_window4_ptr1->set_material(sv_glossy_window_ptr);add_object(wedge_window4_ptr1);BeveledWedge* wedge_window4_ptr2 = new BeveledWedge(y50_unit, y51_unit, r20_unit, r21_unit, rb2_unit, phi0_frame24 , phi1_frame24);wedge_window4_ptr2->set_material(sv_glossy_window_ptr);add_object(wedge_window4_ptr2);BeveledWedge* wedge_window4_ptr3 = new BeveledWedge(y70_unit, y71_unit, r20_unit, r21_unit, rb2_unit, phi0_frame24 , phi1_frame24);wedge_window4_ptr3->set_material(sv_glossy_window_ptr);add_object(wedge_window4_ptr3);double phi0_frame15 = phi1_frame24;double phi1_frame15 = phi0_frame15 + _frame_angle_width;BeveledWedge* wedge_frame15_ptr = new BeveledWedge(y10_unit, y11_unit, r10_unit, r11_unit, rb1_unit, phi0_frame15 , phi1_frame15);wedge_frame15_ptr->set_material(sv_phong_frame_ptr1);add_object(wedge_frame15_ptr);double phi0_wall2 = phi1_frame15;double phi1_wall2 = phi1_unit;BeveledWedge* wedge_wall_ptr2 = new BeveledWedge(y10_unit, y11_unit, r10_unit, r11_unit, rb1_unit, phi0_wall2 , phi1_wall2);wedge_wall_ptr2->set_material(sv_phong_wall_ptr1);add_object(wedge_wall_ptr2);}

5，第五部分：台阶、房顶

这个可以理解问层级数为1的Rosette。

Phong材质，4号砂岩纹理。

创建台阶、房顶的相关代码如下：

////////////////////////////////////////steps and roof, Wedge///////////////////////////////////////double angle_start_s = 0;double angle_end_s = 360;int num_wedges = 9;double y0_s = - 0.1;double y1_s = 0.3;double rb_s = 0.025;double y0_r = 3.7;double y1_r = 4.1;double r0_s = 5.0;double r1_s = 7.0;for (int sj = 0; sj < num_wedges; sj++) {double angle_width = (angle_end_s - angle_start_s) / num_wedges;  // the azimuth angle extent of each wedgedouble phi0_s = angle_start_s + sj * angle_width;double phi1_s = phi0_s + angle_width;BeveledWedge* wedge_steps_ptr = new BeveledWedge(y0_s, y1_s, r0_s, r1_s, rb_s, phi0_s , phi1_s);BeveledWedge* wedge_roof_ptr = new BeveledWedge(y0_r, y1_r, r0_s, r1_s, rb_s, phi0_s , phi1_s);// noise:CubicNoise* noise_step_ptr = new CubicNoise;noise_step_ptr->set_num_octaves(6);noise_step_ptr->set_gain(2);            // not relevant when num_octaves = 1noise_step_ptr->set_lacunarity(0.5);     // not relevant when num_octaves = 1// ramp image:Image* image_step_ptr = new Image;image_step_ptr->read_ppm_file(".\\TextureFiles\\ppm\\sandstone_ramp4.ppm");// marble texture:FBmTextureRamp* sandstone_step_ptr = new FBmTextureRamp(image_step_ptr);sandstone_step_ptr->set_noise(noise_step_ptr);sandstone_step_ptr->set_perturbation(0.1);// transformed sandstone textureInstanceTexture* wedge_sandstone_step_ptr = new InstanceTexture(sandstone_step_ptr);set_rand_seed(20);wedge_sandstone_step_ptr->scale(0.25);wedge_sandstone_step_ptr->rotate_x(20.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_step_ptr->rotate_y(30.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_step_ptr->rotate_z(45.0 * (2.0 * rand_float() - 1.0));wedge_sandstone_step_ptr->translate(10.0 * (2.0 * rand_float() - 1.0), 20.0 * (2.0 * rand_float() - 1.0), 30.0 * (2.0 * rand_float() - 1.0));// material:SV_Phong* sv_phong_step_ptr = new SV_Phong;sv_phong_step_ptr->set_ka(0.25);sv_phong_step_ptr->set_kd(0.75);sv_phong_step_ptr->set_cd(wedge_sandstone_step_ptr);sv_phong_step_ptr->set_ks(0.1);sv_phong_step_ptr->set_exp(20.0);wedge_steps_ptr->set_material(sv_phong_step_ptr);add_object(wedge_steps_ptr);wedge_roof_ptr->set_material(sv_phong_step_ptr);add_object(wedge_roof_ptr);}

6，天空

凹半球面，Phong材质，图片映射

创建相关的代码：

////////////////////////////////////////sky, SpherePartConcave///////////////////////////////////////SpherePartConcave* spc_sky_ptr = new SpherePartConcave(Point3D(0, 0, 0), 1, 0, 360, 0, 90);// image:Image* image_sky_ptr = new Image;
//  image_sky_ptr->read_ppm_file(".\\TextureFiles\\ppm\\MorningSky.ppm");image_sky_ptr->read_ppm_file(".\\TextureFiles\\ppm\\EveningSky.ppm");// image based texture:ImageTexture* texture_image_sky_ptr = new ImageTexture;texture_image_sky_ptr->set_image(image_sky_ptr);InstanceTexture* it_image_sky_ptr = new InstanceTexture(texture_image_sky_ptr);it_image_sky_ptr->scale(1000000);// material:SV_Phong* sv_phong_sky_ptr = new SV_Phong;sv_phong_sky_ptr->set_ka(0.1);sv_phong_sky_ptr->set_kd(0.25);sv_phong_sky_ptr->set_cd(texture_image_sky_ptr);sv_phong_sky_ptr->set_ks(0.1);sv_phong_sky_ptr->set_exp(20.0);Instance* instance_spc_sky_ptr = new Instance(spc_sky_ptr);instance_spc_sky_ptr->scale(1000000);instance_spc_sky_ptr->rotate_x(-5);
//    instance_spc_sky_ptr->translate(0, -1000, 0);instance_spc_sky_ptr->set_material(sv_phong_sky_ptr);add_object(instance_spc_sky_ptr);

7，World::build()中的其他设置

    int num_samples = 16;int a = 1;vp.set_hres(1000/a);vp.set_vres(500/a);vp.set_samples(num_samples);tracer_ptr = new Whitted(this);Pinhole* pinhole_ptr = new Pinhole;pinhole_ptr->set_eye(0.0, 2.6, 6.8);pinhole_ptr->set_lookat(0.0, 0.0, -8);pinhole_ptr->set_view_distance(600/a);pinhole_ptr->compute_uvw();set_camera(pinhole_ptr);PointLight* point_light_ptr1 = new PointLight;point_light_ptr1->set_location(0, 3, -5);point_light_ptr1->scale_radiance(2.0);point_light_ptr1->set_cast_shadow(true);add_light(point_light_ptr1);PointLight* point_light_ptr2 = new PointLight;point_light_ptr2->set_location(0, 3, 5);point_light_ptr2->scale_radiance(2.0);point_light_ptr2->set_cast_shadow(true);add_light(point_light_ptr2);

8，测试图形

8.1 pinhole_ptr->set_view_distance(200/a);

分辨率1000*500，单像素点采样16次，耗时13898s。

8.2 pinhole_ptr->set_view_distance(400/a);

分辨率1000*500，单像素点采样16次，耗时12650s。

8.3 pinhole_ptr->set_view_distance(600/a);

分辨率1000*500，单像素点采样16次，耗时13778s。

8.4 pinhole_ptr->set_view_distance(800/a);

分辨率1000*500，单像素点采样16次，耗时12568s。

8.5 改变门的起始、终止角度

前面对应的角度都是：
double angle_start = 0;
double angle_end = 360;

现在将角度改为：
double angle_start = -90;
double angle_end = 270;

发现门的位置发生了旋转。其实对于柱子、台阶和房顶，都可以通过改变其对应的起始、终止角度来改变其在场景中所处的位置。

9，其他说明

完整代码下载链接：
http://download.csdn.net/detail/libing_zeng/9816036

Q102：光线追踪场景（5）——驭龙台相关推荐

Q102：光线追踪场景（2）——PLYs（多种模型汇集）
0,引入这一章节里,trace的图形包含多种PLY文件表示的图形. 比如:bunny.dragon.hand skeleton.horse等. 主要涉及两件事情: 1,将这些模型添加到场景中: 2, ...
Q102：光线追踪场景（4）——面朝大海
0,引入想象这么一个场景: 海边有一个古老的凉亭.雕刻着古时壁画的屋檐:砂岩的地板:亭内摆放着一个木质的茶桌:茶桌上摆着大理石的茶杯和茶壶:紧挨着茶桌有一个圆形的坐垫:小白兔和小灰兔静静地蹲坐在地板 ...
Q102：光线追踪场景（3）——Two Horses
0,引入这个场景中包含两匹马,不知道怎么起名,所以就叫"Two Horses"啦.还有就是用到各种反射模型.各种光照模型.各种纹理.PLY格式的几何模型. 贴图如下: 1,测试代 ...
Q102：光线追踪场景（1）——地球仪
0,引入这一章节里,咱们trace这样一个包含地球仪的场景,直接贴出结果图形啦! 这个场景中包含如下几部分: 1,地球仪的底座(1个回旋面+1个圆柱面,Phong材质,木纹纹理): 2,地球仪的主体 ...
基于 GL Pipeline 与光线追踪技术的融合实现的台球模拟器【100010712】
基于 GL Pipeline 与光线追踪技术的融合实现的台球模拟器一.Project Title 基于 GL Pipeline 与光线追踪技术的融合实现的台球模拟二.Abstract 本项目实现了 ...
OpenGL实现基本的光线追踪
光线追踪 NZL 21/1/13 一.前言这是我图形学这门课的期末作业,我觉得还挺有意思的就写一篇博客记录一下.本身这门课学的技术都是四五十年前的了,相当于图形学的入门课程,所以用到的公式,方法可能 ...
2台xenserver组成的资源池开启HA存在的问题
最近有人在问2台xenserver组成的resources pool 开启HA后存在啥样的问题? 先看下xenserver管理员手册上写的: Citrix 建议您仅对至少包含 3 个 XenServe ...
光线追踪技术的理论和实践(面向对象)
光线追踪技术的理论和实践(面向对象) 收藏此文于2010-06-18被推荐到CSDN首页如何被推荐? *原创文章,转载请注明出处* 光线追踪技术的理论和实践(面向对象) Theory & ...
年底大会火爆，看“瑶台”如何搭建一场高质量沉浸式大会
随着年关将近,各类大型活动扎堆举办已经不足为奇,但是疫情防控的常规化使得许多传统线下活动不得不延期或者改为线上. 5G 技术的应用落地和数字化转型的提速,使得人们在使用稳定.高效的线上会议的同时,对更 ...

Q102：光线追踪场景（5）——驭龙台