About DIY 3D Drawing
In making a 3D image for beginners it may seem difficult, where to start, but if you are a beginner who is already proficient in 2D no problem, now live understanding of 3D images, 3D images are 2D drawings in extrusion (not made high), height will appear if "WCS" is changed to "UCS", because the position in "WCS" of its 3D image will not be visible, because the "WCS" position is the same as you see from above. .
Well imagine you see a matchbox when viewed from above, just a rectangular shape only, as if the match is only in the form of a rectangle only, now your position in the fox that has been seen from above is now visible on the door. Side, it will be seen that this match has an altitude.
For that you need to know the extrude function that will be used when the object is an entity, eg circle, ellipse and rectang, if you make a grid by using "LINE", it has not become one unity, you have to do its function. from "PEDIT" or "REGION" sometimes when pedit is difficult or often fails because there is a gap that is not visible to our eyes, this is often experienced by the drafter beginners.
Hopefully useful ,,, thanks.