Not all alignment tangents being curved

[kaiknux]

Hi everyone,

I'm having trouble designing an alignment from an pre existing road. I drew the polyline and I need it to get curved between tangents (since there isn't a label that informs the angles between these tangents). But when I do it, not all the tangents get curved, just a part of it. The weird thing is that the whole polyline gets converted to an alignment and labeled correctly, but only the tangents near the initial stations get curved.

Any ideas about what could be done?

Other issue is that even if I draw another alignment in the same X, Y, i can't project it to my existing profile view. I can't offset my EG so i can weed it and design my alignment for my pressure pipe.

I'm more experienced working with pound and slopes in architecture design and this part of C3D seems more complicated

Thanks a lot.

[kaiknux]

When I break my polyline and try to convert these two "new" polines into alignments, the exact same tangents that got curved before are being curved now, and all the others aren't, again!

[jmayo-EE]

How did you make the pline? Are all of the tangents drwan in the same direction? Were the curves created with the fillet command or similar method that insures tangency? Do the tangents have PI's between the endpoints?

Post a file with the pline only and I can see if I can get what you need.

[kaiknux]

No, it´s on different directions... It wasn't made with fillets, it was a "freehand ortho" polyline.  Yes, i guess there are PIs on these tangents... 

The polyline is the alignment ALINHAMENTO 02

file:

http://www.4shared.com/photo/sllY_El4/Inicio_LAdainha_-_Ribeiro_dant.html?

Thanks again

[jmayo-EE]

If you zip a file you can posty it here. Sorry but I do not use those free upload sites. I will not give them my email nor do I want all the malware that comes when you hit the wrong download button.

[jmayo-EE]

You can always email me directly as well.

johnm   at  conklinassociates   dot    com

[kaiknux]

Please check your inbox. I can't post the .rar or .zip here, since the forum doesn't accept the "z01" extension

[DaveDrahn]

I can't get to your dwg post either. Maybe john will get it, but ingeneral it sounds like you need to verify the accuracy of the alignment as drawn. I usually avoid creating an alignment from a polyline for those reasons. If it's not too much trouble, it usually works out better to explode the pline, fillet the tangents to get real PI's and create a new alignment by layout, snapping to these PI's - adjusting the curve radii afterward (they can be near snapped to the arcs that remain from the exploded pline, so it's also fairly quick). This will give you a solid alignment.

[jmayo-EE]

Ok if you used the default radius value of 200 then most of the curves will not fit between the tangents. In the file I posted I made the alignment and moved the pline over and zooomed to the area of intrest to demonstrate this. I was able to place one curve betwwen these tangents but the out going curve cannot be created because the radius is to large for the incoming tangent.

[jmayo-EE · Accepted solution]

Colinear points on the tangents are killing the conversion. The curves stop everywhere you have a two colinear lines forming one tangent.

Go to the Modify tab, Edit Geometry panel and look for the Weed Feature Line command. Use this on the pline before converting to an alignment to remove the 8 colinear points.

I cleaned up a copy of the pline and was able to get 20m curves at all PI's.

[kaiknux]

Now I understand the problem. I like Dave's hint, but i'll try John's weeding factor first. Understanding this will be very useful to avoid this in the future. I'm very thankful.

[wfberry]

John:

DId you mean NON-colinear?

Bill

[jmayo-EE]

I actually meant collinear with two l's. 😮

All the points on the same linear path. If we have a tangent and break it into two pieces we have colinear lines.  The new endpoints are the colinear PI's. These are the points that mess it up. You can't put a curve  between collinear lines.

[wfberry]

Does non-planar and collinear sound alike?  OK, I didn't think so.

Bill

[kaiknux]

Anyway, I understood and fixed my polyline with the overkill command. Now I'm not getting that problem again  thanks again