1 | #include "SamplingStrategy.h"
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2 | #include "Ray.h"
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3 | #include "Intersectable.h"
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4 | #include "Preprocessor.h"
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5 | #include "ViewCellsManager.h"
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6 | #include "AxisAlignedBox3.h"
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7 |
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8 |
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9 | namespace GtpVisibilityPreprocessor {
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10 |
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11 |
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12 | SamplingStrategy::SamplingStrategy(const Preprocessor &preprocessor):
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13 | mPreprocessor(preprocessor)
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14 | {
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15 | }
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16 |
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17 |
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18 | SamplingStrategy::~SamplingStrategy()
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19 | {
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20 | }
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21 |
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22 | int
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23 | SamplingStrategy::GenerateSamples(const int number,
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24 | SimpleRayContainer &rays) const
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25 | {
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26 | SimpleRay ray;
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27 | int i = 0;
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28 | for (; i < number; i++) {
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29 | if (!GenerateSample(ray))
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30 | return i;
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31 | rays.push_back(ray);
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32 | }
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33 |
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34 | return i;
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35 | }
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36 |
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37 |
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38 | /*********************************************************************/
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39 | /* Individual sampling strategies implementation */
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40 | /*********************************************************************/
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41 |
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42 |
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43 | bool ObjectBasedDistribution::GenerateSample(SimpleRay &ray) const
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44 | {
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45 | Vector3 origin, direction;
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46 |
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47 | mPreprocessor.mViewCellsManager->GetViewPoint(origin);
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48 |
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49 | Vector3 point;
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50 | Vector3 normal;
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51 | //cout << "y";
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52 | const int i = (int)RandomValue(0, (float)mPreprocessor.mObjects.size() - 0.5f);
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53 |
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54 | Intersectable *object = mPreprocessor.mObjects[i];
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55 |
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56 | object->GetRandomSurfacePoint(point, normal);
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57 | direction = point - origin;
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58 |
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59 | // $$ jb the pdf is yet not correct for all sampling methods!
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60 | const float c = Magnitude(direction);
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61 |
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62 | if (c <= Limits::Small)
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63 | return false;
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64 |
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65 | // $$ jb the pdf is yet not correct for all sampling methods!
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66 | const float pdf = 1.0f;
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67 |
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68 | direction *= 1.0f / c;
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69 | ray = SimpleRay(origin, direction, pdf);
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70 |
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71 | return true;
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72 | }
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73 |
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74 |
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75 | bool ObjectDirectionBasedDistribution::GenerateSample(SimpleRay &ray) const
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76 | {
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77 | Vector3 origin, direction;
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78 | const int i = (int)RandomValue(0, (Real)mPreprocessor.mObjects.size() - 0.5f);
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79 | Intersectable *object = mPreprocessor.mObjects[i];
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80 |
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81 | Vector3 normal;
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82 | //cout << "x";
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83 | object->GetRandomSurfacePoint(origin, normal);
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84 | direction = UniformRandomVector(normal);
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85 |
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86 | origin += 0.1f * direction;
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87 |
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88 | const float c = Magnitude(direction);
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89 |
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90 | if (c <= Limits::Small)
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91 | return false;
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92 |
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93 | // $$ jb the pdf is yet not correct for all sampling methods!
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94 | const float pdf = 1.0f;
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95 |
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96 | direction *= 1.0f / c;
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97 | ray = SimpleRay(origin, direction, pdf);
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98 |
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99 | return true;
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100 | }
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101 |
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102 |
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103 | bool DirectionBasedDistribution::GenerateSample(SimpleRay &ray) const
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104 | {
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105 | Vector3 origin, direction;
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106 | mPreprocessor.mViewCellsManager->GetViewPoint(origin);
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107 |
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108 | direction = UniformRandomVector();
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109 | const float c = Magnitude(direction);
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110 |
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111 | if (c <= Limits::Small)
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112 | return false;
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113 |
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114 | const float pdf = 1.0f;
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115 |
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116 | direction *= 1.0f / c;
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117 | ray = SimpleRay(origin, direction, pdf);
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118 |
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119 | return true;
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120 | }
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121 |
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122 |
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123 | bool DirectionBoxBasedDistribution::GenerateSample(SimpleRay &ray) const
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124 | {
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125 | Vector3 origin, direction;
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126 | mPreprocessor.mViewCellsManager->GetViewPoint(origin);
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127 |
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128 | const float alpha = RandomValue(0.0f, 2.0f * (float)M_PI);
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129 | const float beta = RandomValue((float)-M_PI * 0.5f, (float)M_PI * 0.5f);
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130 |
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131 | direction = VssRay::GetDirection(alpha, beta);
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132 |
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133 | const float c = Magnitude(direction);
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134 |
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135 | if (c <= Limits::Small)
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136 | return false;
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137 |
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138 | const float pdf = 1.0f;
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139 |
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140 | direction *= 1.0f / c;
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141 | ray = SimpleRay(origin, direction, pdf);
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142 |
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143 | return true;
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144 | }
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145 |
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146 |
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147 | bool SpatialBoxBasedDistribution::GenerateSample(SimpleRay &ray) const
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148 | {
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149 | Vector3 origin, direction;
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150 |
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151 | mPreprocessor.mViewCellsManager->GetViewPoint(origin);
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152 | direction = mPreprocessor.mKdTree->GetBox().GetRandomPoint() - origin;
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153 | //cout << "z";
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154 | const float c = Magnitude(direction);
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155 |
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156 | if (c <= Limits::Small)
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157 | return false;
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158 |
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159 | const float pdf = 1.0f;
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160 |
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161 | direction *= 1.0f / c;
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162 | ray = SimpleRay(origin, direction, pdf);
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163 |
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164 | return true;
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165 | }
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166 |
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167 |
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168 | bool ReverseObjectBasedDistribution::GenerateSample(SimpleRay &ray) const
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169 | {
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170 | Vector3 origin, direction;
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171 |
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172 | mPreprocessor.mViewCellsManager->GetViewPoint(origin);
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173 |
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174 | Vector3 point;
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175 | Vector3 normal;
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176 | //cout << "y";
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177 | const int i = (int)RandomValue(0, (float)mPreprocessor.mObjects.size() - 0.5f);
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178 |
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179 | Intersectable *object = mPreprocessor.mObjects[i];
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180 |
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181 | object->GetRandomSurfacePoint(point, normal);
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182 |
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183 | direction = origin - point;
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184 |
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185 | // $$ jb the pdf is yet not correct for all sampling methods!
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186 | const float c = Magnitude(direction);
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187 |
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188 | if ((c <= Limits::Small) || (DotProd(direction, normal) < 0))
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189 | {
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190 | return false;
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191 | }
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192 |
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193 | // $$ jb the pdf is yet not correct for all sampling methods!
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194 | const float pdf = 1.0f;
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195 | //cout << "p: " << point << " ";
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196 | direction *= 1.0f / c;
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197 | // a little offset
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198 | point += direction * 0.01f;
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199 |
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200 | ray = SimpleRay(point, direction, pdf);
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201 |
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202 | return true;
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203 | }
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204 |
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205 |
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206 | bool ViewCellBorderBasedDistribution::GenerateSample(SimpleRay &ray) const
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207 | {
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208 | Vector3 origin, direction;
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209 |
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210 | ViewCellContainer &viewCells = mPreprocessor.mViewCellsManager->GetViewCells();
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211 |
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212 | Vector3 point;
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213 | Vector3 normal, normal2;
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214 |
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215 | const int vcIdx = (int)RandomValue(0, (float)viewCells.size() - 0.5f);
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216 | const int objIdx = (int)RandomValue(0, (float)mPreprocessor.mObjects.size() - 0.5f);
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217 |
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218 | Intersectable *object = mPreprocessor.mObjects[objIdx];
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219 | ViewCell *viewCell = viewCells[vcIdx];
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220 |
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221 | //cout << "vc: " << vcIdx << endl;
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222 | //cout << "obj: " << objIdx << endl;
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223 |
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224 | object->GetRandomSurfacePoint(point, normal);
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225 | viewCell->GetRandomEdgePoint(origin, normal2);
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226 |
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227 | direction = point - origin;
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228 |
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229 | // $$ jb the pdf is yet not correct for all sampling methods!
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230 | const float c = Magnitude(direction);
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231 |
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232 | if ((c <= Limits::Small) /*|| (DotProd(direction, normal) < 0)*/)
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233 | {
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234 | return false;
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235 | }
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236 |
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237 | // $$ jb the pdf is yet not correct for all sampling methods!
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238 | const float pdf = 1.0f;
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239 | //cout << "p: " << point << " ";
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240 | direction *= 1.0f / c;
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241 | ray = SimpleRay(origin, direction, pdf);
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242 |
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243 | //cout << "ray: " << ray.mOrigin << " " << ray.mDirection << endl;
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244 |
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245 | return true;
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246 | }
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247 |
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248 |
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249 | #if 0
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250 | bool ObjectsInteriorDistribution::GenerateSample(SimpleRay &ray) const
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251 | {
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252 | Vector3 origin, direction;
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253 |
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254 | // get random object
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255 | const int i = RandomValue(0, mPreprocessor.mObjects.size() - 1);
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256 |
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257 | const Intersectable *obj = mPreprocessor.mObjects[i];
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258 |
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259 | // note: if we load the polygons as meshes,
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260 | // asymtotically every second sample is lost!
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261 | origin = obj->GetBox().GetRandomPoint();
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262 |
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263 | // uniformly distributed direction
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264 | direction = UniformRandomVector();
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265 |
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266 | const float c = Magnitude(direction);
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267 |
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268 | if (c <= Limits::Small)
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269 | return false;
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270 |
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271 | const float pdf = 1.0f;
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272 |
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273 | direction *= 1.0f / c;
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274 | ray = SimpleRay(origin, direction, pdf);
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275 |
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276 | return true;
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277 | }
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278 |
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279 | #endif
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280 |
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281 | bool
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282 | RssBasedDistribution::GenerateSample(SimpleRay &ray) const
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283 | {
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284 | return false;
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285 | }
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286 |
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287 | }
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288 |
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289 |
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