Rviz tool plugin for creating polygon selections

• Left mouse button click: Add point to current polygon
• Middle mouse button click: Erase current polygon selection
• Right mouse button click: Finish current polygon and start new polygon
• Shortcut delete, backspace: Remove all polygons

• Lasso: click and hold left mouse button while drawing a shape
• Click: click and release the left mouse button to drop a vertex in the polygon

Toggle betweeen the modes by selecting the Lasso mode check box in the tool properties panel