I have been using blender for two days and i am embarking on making my first project (although simple, consisting mostly out of simple geometric shapes). Now i stand before this puzzle.
In the attached screenshot, you see three objects. Now, i learned how to snap objects to the grid. I had tried it several times and it worked everytime. The way i did this was by translating it on the z axis, down to the grid with snapping enabled (increments, absolute grid allignment). The problem is that this works properly for the active object in the screenshot, but when i try it with the other two they will hover slightly above the grid. I don’t know what is the cause, and was hoping anybody could shed some light on the issue.
The middle object has its origin on the bottom corner (orange dot) the other two have their origin at some point other point. The origin point is the actual location of the object so if you snap the object to a grid you are snapping this point. Depending on the size of the object the base may not therefore line up with the ground plane.
You have the options to change the position of the object origin in the toolshelf (Set Origin) or in the Object / Transform menu