I want to convert polygons into points using QGIS.
I know how it's done in ArcGIS Desktop.
How can I implement it using QGIS?
You can do the "Centroids" in QGIS using:
Vector > Geometry Tools > Centroids
You can "Extract Vertices" in QGIS using:
Vector > Geometry Tools > Extract Vertices
There is also a tool called "Extract specific vertices"
If you want to decide on your own point spacing, you can use the Sextante Toolbox with SAGA functionality activated (you'll need to install SAGA - http://www.saga-gis.org/en/index.html - and specify the installation path in sextante).
Use the "Polygons to Lines" geoalgoritm followed by the "Lines to Points" one. You can create a model in sextante that combines these into one step as well.
Note: you have to make sure you install the right version of SAGA - I think its 2.0.8
Export polygon ;ayer to SHP Open with CloudCompare Edit -->polyline-->sample points save resilt vertices as csv . Import with QGIS (add layer--> delimited text layer)
If you want to convert polygon to point using QGIS. Then use
Vector > Analysis Tools > Mean Coordinate.