I’ve seen this asked a couple of times but I have yet to actually see an actual proposal for how to do this correctly. The level that I need to render needs to have a flat grid laid down to help people with judging distances and I’m wondering if UDK4 has a best practices way of drawing just lines. I can imagine ways of hacking this in using the debug lines, but that feels like the incorrect way of doing it. So, anyone know of a “correct” way of doing this?
You could just put a texture of a grid on a plane, very easy
My primary issue with that is I’d need to make sure the artist doing the grid gets the units of the grid precisely right. If I could control the creation of the grid programmatically I could guarantee that they’re right and/or fix the issue quickly in code.
You can map your texture in world space, using the absolute world position x/y, for precise measurements.
Zwabbit, making a large plane with a 100% acurate grid is incredibly easy. Heres how.
Make a large plane inside your 3D modeling software. Subdivide that plane into as many squares as you like to correspond to the size of the grid.
For example if you want a 25 meter x 25 meter plane, subdivide it 25 times so that your plane is now made of 25 squares by 25 squares.
Then individually Unwrap each plane so that each plane is sitting on exactly the same UV space. Then make a square texture with say the very edges all white
and the inside black. Like this for example:
Does that all make sense? Need any clarification? Please ask. 
And heres the result :):
Hmm, what if I’m trying to create a circular grid? The intent is to represent a solar system and each grid represents (I’ll need to double check the exact value) arcs 12 degrees around the star. I’m not really much of an art guy so my understanding of what is feasible/practical/etc for this kind of stuff is minimal.
As an aside, I am really liking the new forum, the community seems to be a lot more involved and engaged.
You could make any shape like that very quickly and easily, and exactly to the right dimensions.
Zwabbit, something like this?
Yep, nice. Thanks for the pointers, now to go bug my artist friend.
just to let ya know, I didnt use a Texture to make that blue circular glowing grid. I made a Mesh inside Blender 3D. Imported it into UE4 and applied a simple emissive transparent material to it. 
Thanks for the idea. Not being an artist first I’ve been meticulously adjusting an arbitrary texture and uv to line up with my grid size. Can’t believe I didn’t think to just make a grid in Blender then export that out.
oh well, the more you know!!