Hello,
The cost change (http://masagroup.github.io/recastdetour/classdtQueryFilter.html#details)
m_filter->setAreaCost((int)PolyArea::POLYAREA_GROUND, 1.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_DANGER, 2.0f);
m_filter->setAreaCost((int)PolyArea::POLYAREA_BIGDANGER, 15.0f);