use atof() instead of sscanf()

WFObj.cc

@@ -280,7 +280,7 @@ WFObj::Vertex WFObj::readVertex(const vector<string> & parts)
     Vertex v;
     for (int i = 1; i < partslen && i <= 4; i++)
     {
-        sscanf(parts[i].c_str(), "%f", &v[i - 1]);
+        v[i - 1] = atof(parts[i].c_str());
     }
     return v;
 }