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Creating 3D poly from Alignment and Profile

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Message 1 of 11
rui.viegas
832 Views, 10 Replies

Creating 3D poly from Alignment and Profile

Hello,

 

I've been asked to create a 3D poly from a given alignment and profile.

 

The only way I know to do it, is to create a feature line using the "createfeaturelinefromalign" command and exploding it.

 

My problem is that the resulting 3D poly loses a lot of the "precision" the feature line had (how closely it followed the alignment).

 

 

So does anyone know of another way to create a 3D poly or of some method of maintaining the feature precision when exploding it?

 

 

Thanks in advance,

10 REPLIES 10
Message 2 of 11
jmayo-EE
in reply to: rui.viegas

I seem to get a better FL if I do not use the FL from alig command. Instead, edit the profile style to display the 3D Chain in Model views and explode that. Copy the result to the clipboard and use UNDO to get back to the live profile. Paste the result back into the file.

John Mayo

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Message 3 of 11
jmayo-EE
in reply to: jmayo-EE

Also when you use the FL from Alig command what values do you set for the weeding. You can try to minimize the values for grade and distance and see if you get better results.

John Mayo

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Message 4 of 11
rui.viegas
in reply to: jmayo-EE

I played with the weeding values, and it definitely had an impact when creating the FT but after exploding it the results were always bad in terms of the 3D poly's precision.

 

Your solution for creating the 3D poly using the 3D chain was quite usefull and gave very acceptable results. Thank you.

 

I found one thing curious however, and did some tests and always ended up with the same results.

All 3D polys made by using the 3D chain didn't show the last meter of the alignment. it was easy to correct that but does this happens top you when you use the 3D chain method?

 

 

Again thanks for the help

Message 5 of 11
jmayo-EE
in reply to: rui.viegas

"All 3D polys made by using the 3D chain didn't show the last meter of the alignment"

 

Without seeing the data I would bet that the alignment is longer than the corresponding profiles. Make sure the profiles extend through the full alignment stationing or shorten the alignment.

John Mayo

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Message 6 of 11
rui.viegas
in reply to: jmayo-EE

Thought that as well but double checked the profile's lenght and it matched the alignment's lenght

 

I also tried to shorten the alignment's lenght about 10m without making any change to the profile, in order to guarantee that the profile's lenght was not the problem, and came out short the last meter. 

 

The last test I made was to create a test file with a simple alignment and profile from stracth but alas that last meter still eluded me.

 

I'm currently using Civil 2011.

Message 7 of 11
jmayo-EE
in reply to: rui.viegas

Unless this profile is from a corridor surface that is not fully designed to the extents of the profile then a solution eludes me as well. Sry.

John Mayo

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Message 8 of 11
AllenJessup
in reply to: jmayo-EE

And if you want to increase the tessellation of the Chain. See [this] post.

 

Allen

 

3D Chain tesselation.PNG



Allen Jessup
Engineering Specialist / CAD Manager

Message 9 of 11
neilyj666
in reply to: jmayo-EE


@Anonymous wrote:

I seem to get a better FL if I do not use the FL from alig command. Instead, edit the profile style to display the 3D Chain in Model views and explode that. Copy the result to the clipboard and use UNDO to get back to the live profile. Paste the result back into the file.


Can you expand on this a bit as I'm a little lost....

 

I've got the profile in model view (SW isometric) but i don't follow the next steps as when I explode the 3D chain it produces a block and when exploded again the elevations are way out

 

Thanks

 

neilyj (No connection with Autodesk other than using the products in the real world)
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Message 10 of 11
jmayo-EE
in reply to: neilyj666

Perhaps something changed in 2013? I get perfect 3d polys after explodoing twice. Perfect results from a surface and layout profile.

John Mayo

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Message 11 of 11
AllenJessup
in reply to: rui.viegas

Neil

 

I've done this a few times and never had much of a problem. The only thing is that if the tessellation of the 3D Chain is off the stationing you will see some difference, especially in vertical curves, when comparing elevations at even stations. So increasing tessellation may help. But I don't know what you consider as way off.

 

Allen



Allen Jessup
Engineering Specialist / CAD Manager

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