PointCloud: Fix calculation of bounding radius

Bounding sphere should be local to bounding box, not consider max length of point vectors.
If the cloud is shifted strongly into some direction, those lengths will be large,
although the bounding box (and sphere) can be small.

src/rviz/ogre_helpers/point_cloud.cpp

@@ -481,7 +481,6 @@ void PointCloud::addPoints(Point* points, uint32_t num_points)
   Ogre::AxisAlignedBox aabb;
   aabb.setNull();
   uint32_t current_vertex_count = 0;
-  bounding_radius_ = 0.0f;
   uint32_t vertex_size = 0;
   uint32_t buffer_size = 0;
   for (uint32_t current_point = 0; current_point < num_points; ++current_point)
@@ -540,7 +539,6 @@ void PointCloud::addPoints(Point* points, uint32_t num_points)
     }
 
     aabb.merge(p.position);
-    bounding_radius_ = std::max(bounding_radius_, p.position.squaredLength());
 
     float x = p.position.x;
     float y = p.position.y;
@@ -571,6 +569,7 @@ void PointCloud::addPoints(Point* points, uint32_t num_points)
   op->vertexData->vertexCount = current_vertex_count - op->vertexData->vertexStart;
   rend->setBoundingBox(aabb);
   bounding_box_.merge(aabb);
+  bounding_radius_ = bounding_box_.getHalfSize().length();
   ROS_ASSERT(op->vertexData->vertexCount + op->vertexData->vertexStart <=
              rend->getBuffer()->getNumVertices());
 
@@ -620,13 +619,12 @@ void PointCloud::popPoints(uint32_t num_points)
 
   // reset bounds
   bounding_box_.setNull();
-  bounding_radius_ = 0.0f;
   for (uint32_t i = 0; i < point_count_; ++i)
   {
     Point& p = points_[i];
     bounding_box_.merge(p.position);
-    bounding_radius_ = std::max(bounding_radius_, p.position.squaredLength());
   }
+  bounding_radius_ = bounding_box_.getHalfSize().length();
 
   shrinkRenderables();