I find it helps to break down the problem into finite steps on paper first.
For instance you know you will need to:
-get an event from the player ( a click or keypress probably)
-know where the player is looking, or where the player is trying to place the object (likely use traces for this)
-spawn an object
-position the object correctly in the world
once you have the basic requirements broken down you can figure out strategies for each of them in more detail.
@ can i ask how you did the snaping to corners if its not a trade secret. ;)?
And are you using tags, and are etch building elements a seperate actor or 1 BPs with instenced meshes?
Edit: I have an idea now it should be rather simple to use the Bounds of the mesh to get the correct cordinats
Also i can`t get the page to load it downloads the data but nothing happens after.
Am running Firefox, also tryed with IE and Chrome. no luck
So i got the basic functionality now i wasted alot of time trying to do this with overlapping events first.
Before i realized i needed to use traces, anyways long way to go, working on the snaping to other objects now.
That i think will take a bit time.