Use more joints for final merge.

spt/triangulator.cpp

@@ -1534,7 +1534,7 @@ cv::Mat TriangulatorInternal::merge_group(const std::vector<cv::Mat> &poses_3d,
     }
 
     // Select the best-k proposals for each joint that are closest to the initial pose
-    int keep_best = 3;
+    int keep_best = std::max(3, num_poses / 3);
     cv::Mat best_k_mask = cv::Mat::zeros(num_poses, num_joints, CV_8U);
     for (int j = 0; j < num_joints; ++j)
     {