Make diagonal grid in QGIS, divide square into squares

Question

I have square polygon which is aligned under some degree and I want to divide this square to, for example, 25 smaller squares, which must be under the same degree in this square polygon. How this can be achieved?

Answer 1

From some quick searching it doesn't appear the Vector -> Research Tools -> Vector Grid, Geoalgorithms > Vector creation tools > Create Grid, or MMQGIS plugin allow for rotation in grid creation. The easiest thing to do would probably be create the grid and move/rotate it manually.

Start by determining the length of one side of your square. Divide that by the number of rows/columns you want. Using a tool mentioned above, create the grid using the appropriate values for cell size and number of columns. Using the editing tools with snapping, move the new grid to align its bottom-left corner with that of your square. You can then either attempt to manually rotate the grid about that matched corner point so that the upper-left or lower-right corners match, or measure the angle between the lines and use that value to rotate the grid (again, about the matched corner) the specified angle.

Other questions related to rotating features (which may be somewhat dated now):

• Is there a Rotate Tool in QGIS?
• Rotating a vector layer in QGIS with qgsAffine (or other method)?

Also note in the current documentation the Rotate Features tool under Advanced Digitzing.