Light & shade fx: enveloping an existing sector with a new surrounding sector

What is shown here will work in ( just about ) any situation where you have to make a sector outside one that has already been created.
 
In the screen captures that follow, an arrow indicates the sector we are looking at. To the left we see the lonely box/table/light sector in the middle of a room. It could be, for the sake of a generic example, it could be any old sector. We were talking about a light, a box or table under it, and how to create a surrounding sector without making the Build engine freak out.
First, because it has not been mentioned else where, North is the top of the screen or picture, East is to the right, West is to the left, and of course, South is toward the bottom of the screen or the picture.

Start making a sector from one point on the existing sector. In this example, the first outer sector was started from the North West point of the box sector over to the North East corner of the box sector. Then, starting from the South East point of the box sector, draw the next sector from there to the outer point of the first sector that was drawn. Remember, when drawing sectors from an object, unless it's from a wall to an object, you should start from the object outward.



The next two screen captures show the last few steps just described.
Start drawing the next sector from the South West point of the inner sector and draw outward and then toward the outer point of the last sector drawn. Then all you would have to do is join the outer points (North and South) together on the West side of the sectors. The first sector is now enclosed with four new sectors. We are not finished, yet. The next two captures show what was just described.


Go into 3D mode and check to see that everything is all right. It should be. I have never run in to a problem making a sector outside of an existing one by doing it this way but check it, anyway. All that is left to do is join the outer sectors together; there you have it! The following two screen captures show the final steps.


This all might sound crazy, like it would be too much work but really, the whole procedure takes about one minute. It takes more time and energy trying to explain it than actually doing it. Below is the the final capture depicting the old sector in the middle of the new surrounding sector (and with no side effects). Simple procedures that take way more time to explain than to do. Using the tips just described, you should seldom, if ever, run in to the problems mentioned at the start of these tutorials.


notes
You join a sector to another in 2D mode by placing the cursor inside one sector, pressing the j key and then pressing the j key inside the sector you want to join it with. You must also be careful to understand that the first sector you press the j key in will carry over its ceiling height to the next sector. That is, if the first sector you press the j key in is 32 units in height, the next sector you press the j key in, regardless of ceiling height, will also take on the same ceiling height. Be sure that you join the sectors in a sequence that will result as you had intended.