fix problem of root coordinates
Merge remote-tracking branch 'upstream/hydro-devel' into hydro-devel-fix-root-coords
fix debug message
Merge pull request #58 from YoheiKakiuchi/hydro-devel-fix-root-coords

Fix root coords
Merge remote-tracking branch 'upstream/hydro-devel' into hydro-devel-fix-visual-and-collision