Intersection AutoSnap Marker does not appear

[Anonymous]

I work with polylines to establish areas, hatching, etc. so I have a lot of lines that overlap. The intersection snap will not show the AutoSnap Marker when trying to select a reference line that is overlapping another line. 

For example, draw a line. Copy it from an endpoint and paste it to the same endpoint. Now you have 2 overlapping lines. Now draw another line at 90 degrees to the first line. Do the same and copy it, then paste it on top of itself. Now try to draw a line, circle, rectangle, etc. starting at the intersection of the two double lines. The AutoSnap Marker does not appear. If you erase the top line on both of the examples and try to draw something to the intersection, now it works fine.

Is there a variable that I can change so it will always show the intersection AutoSnap Marker?

[Alfred.NESWADBA]

Hi,

I have tried your steps, even if I have two doubled lines crossing I get the intersection object snap shown (running object snap as well as manual/temporary object snap).

Using AutoCAD 2019 Update 1.2 ... which version of AutoCAD (Map3D) are you using?

- alfred -

[ChicagoLooper]

Like @Alfred.NESWADBA I cannot replicate your issue. It sounds like the copied lines have different elevations and reside above the original lines so no intersection is being detected due to the z-values. This can happen in crowded drawings when pasting a duplicate line to an endpoint of another line with an elevated z. Although original line and receiving line  share the same endpoint (x,y) coordinates, only one of the lines has a z-value of zero. If the intent was to paste the duplicate line directly on top of the original but the result is a paste onto the elevated line, then you won't get a proper intersection.

You can easily test this  by isolating the line.

1. Select the line you wish to copy.
2. Right click>Isolate objects>Isolate selected objects.
3. Copy the line and paste the duplicate onto the original.
4. Right click in a blank area, Isolate objects>end isolation.

By isolating the object, you can eliminate any interference that may cause you to paste the duplicate in the wrong location.

[Anonymous]

Thank you for the reply; however, the lines are not 3D, nor do they have an elevation set to one endpoint or the other. I simply draw a new line anywhere (in a new drawing), I just copy or draw another line on top if you will. That way I know for sure they are both at the same elevation (I also check the properties window). Then when I try to draw a circle or line or anything that requires a starting point and try to do the intersection or apparent intersection snaps, I'm not getting an AutoSnap Marker on any line that has another line on top or below (or stacked on top of one another). In my example, the lines do not actually cross. I am trying to reference each of the lines in the example separately because in most cases I am trying to snap to an intersection of two lines that don't necessarily touch or cross, but more like an imaginary point where they would intersect if they were extended to one another (The Snap seems to work just fine if they actually cross) Sorry, I don't think I explained that very well in my initial post. If you try it again with the lines separated as I have shown in the attachments and still aren't having the same issue, then I'm not sure??

How I've been working around it is I simply draw a line on the polyline that would intersect and extend it to the point I need. That method is fine, but when you have to do it pretty frequently it becomes very bothersome.

I have attached some screenshots, but I'm not sure they'll do you any good. If you look at the first one you'll see that in my properties window it shows I have selected the 4 lines and they are all at Z=0.0000 ( I also entered zero for both start z and end z to make sure it wasn't some tiny number off) the other two screenshots are showing which snap I'm selecting and what happens after. It should be showing the AutoSnap Marker, but I have to erase one of the lines before I get the AutoSnap Marker to show. Normally I would select the first line, then the second line and my starting point would be the intersection of those two referenced lines. Thank you again for the feedback!

[Anonymous]

Sorry, I forgot to mention that in my case the lines don't actually touch. Most of the time I am trying to reference two lines that don't necessarily touch, but would intersect if they were extended to one another. I will include some screen shots to give you a better idea of what I'm talking about. I am using Map 3D 2017, but I've tried it on previous versions and it does the same thing. Try it again where the lines don't actually touch. Then try erasing one of the lines and do it again. You should get the AutoSnap Marker if you reference the single line first. For whatever reason I've found that it only needs the first reference to be a single line.

[ChicagoLooper]

Yeah, OK, whatever. I run into this all the time and use Object Snap Tracking (F11) with Orthomode (F8) activated.  The combination of those 2 functions completely and easily fulfill the need you describe.

[Anonymous]

Ok, I guess that's another round-about way of doing it. Not exactly a solution. I thought there was a variable you could change so you wouldn't have to perform other operations to achieve the same result as you would expect out of an intersection snap.

And could you explain how your option works if the lines aren't 90 degrees to each other?

[ChicagoLooper]

You can perform 'polar tracking' for incremental angles but they must be listed on the Polar Tracking tab/Polar Angle Settings section of Drafting Settings. If the angle is not listed, then polar tracking isn't available. You can however, extend two lines so they meet at an apparent intersection. Try this:

1. Enter EDGEMODE on command line and change it to 1.
2. Invoke the EXTEND command, the command line will ask you for objects you wish to extend so select your 2 lines. 
3. Select the endpoints of line 1 and line 2. The lines will meet at a point known as the Apparent Intersection.

[Anonymous]

I appreciate the help; however, I already use EDGEMODE. And the steps you suggested I pretty much already do, I mentioned in one of my previous replies that I simply draw a line on top of my polyline and extend it to where it would intersect. My problem is that it takes more steps and therefore affects productivity. EDGEMODE is nice since it allows you to extend and trim from an (for lack of a better word) "imaginary" intersection or trimming line. I would really like to just change a variable where it selects the first reference line no matter if there's two, three, or a million lines on top of one another. It should be an option. Maybe if the CAD programmers read this, they'll fix it in the next version of the software?? Thanks again for the suggestions!

[Anonymous]

• Simple solution for Intersection AutoSnap Marker 

Type 

AUTOSNAP(x) ;

x value shall be 41 or more and max  is 63 and it works GREAT..!!

Below 40 intersection AUTOSNAP may work ; however, ENDPOINT snap (OSNAP/ F3 ..ON) etc...may not work good..

Note:-

• (AUTOCAD 2018 or above...I tried)