Community
Civil 3D Forum
Welcome to Autodesk’s Civil 3D Forums. Share your knowledge, ask questions, and explore popular AutoCAD Civil 3D topics.
cancel
Showing results for 
Show  only  | Search instead for 
Did you mean: 

Surface by Contour

7 REPLIES 7
SOLVED
Reply
Message 1 of 8
teflon
601 Views, 7 Replies

Surface by Contour

I got this surface on the left made by choosing a contour, the same as a polyline.

I would like to see the triangles to cover the contour the same way as the hatch in the object on the right.

No triangle should be build I the corner marked with A! That region is outside the contour/polyline.

What should I do?

I know I could pick the contour as a bounders after making the surface in order to achieve this.

But why does Autocad triangulate outside the polyline at the first place?

 

 

 

7 REPLIES 7
Message 2 of 8
Joe-Bouza
in reply to: teflon

Without a boundary definition the algorithm seeks the nearst node and draws a triangle.

Thank you

Joseph D. Bouza, P.E. (one of 'THOSE' People)

HP Z210 Workstation
Intel Xeon CPU E31240 @ 3.30 Hz
12 GB Ram


Note: Its all Resistentialism, so keep calm and carry on

64 Bit Win10 OS
Message 3 of 8
teflon
in reply to: Joe-Bouza

But isn´t the contour a boundery itself?

Message 4 of 8
neilyj666
in reply to: teflon

....only when you tell Civil 3D that it is.....

neilyj (No connection with Autodesk other than using the products in the real world)
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.

EESignature


AEC Collection 2024 UKIE (mainly Civil 3D UKIE and IW)
Win 11 Pro x64, 1Tb Primary SSD, 1Tb Secondary SSD
64Gb RAM Intel(R) Xeon(R) W-11855M CPU @ 3.2GHz
NVIDIA RTX A5000 16Gb, Dual 27" Monitor, Dell Inspiron 7760
Message 5 of 8
AllenJessup
in reply to: teflon

If you use a contour as a contour it's just a contour. If you use it as a breakline (often work better) it's then a breakline. It's never a boundary unless you define it as one. Define it as an Outer boundary and check NonDestructive Breaklines. That should give you what you want.



Allen Jessup
Engineering Specialist / CAD Manager

Message 6 of 8
teflon
in reply to: AllenJessup

Thanks everybody!

That is what I normally do: use the contour to make a surface then chose the same contour again as an outer boundary!

But this is an extra step to trim off triangles outside the contour!

If one moves along the contour line all triangles should be on the same side, but this is not the case!

But it works fine with hatch command!

 

 

Message 7 of 8
AllenJessup
in reply to: teflon

The hatch command looks for a closed boundary made up of one or more line, arcs or polylines. When creating a surface from a contour Civil 3D does not look at the polyline. It takes the X,Y,Z of each vertex and uses them as a point file to create the surface. You've got 2 very dissimilar commands.

 

You can also create a surface from a thousand contours. If you have 82 closed contours in the surface. What should the program do with them? Not use them as boundaries! This is one of the cases where Autodesk would respond that the program "Works as expected". For once I'd agree with them.



Allen Jessup
Engineering Specialist / CAD Manager

Message 8 of 8
neilyj666
in reply to: teflon


@Anonymous wrote:

Thanks everybody!

That is what I normally do: use the contour to make a surface then chose the same contour again as an outer boundary!

But this is an extra step to trim off triangles outside the contour!

If one moves along the contour line all triangles should be on the same side, but this is not the case!

But it works fine with hatch command!

 

 


I agree that is a pain to have to add the same data twice but it's unavoidable.

 

I presume you mean that the hatch command can find a boundary easily (as can BPOLY and LINEWORKSHRINKWRAP) but these work with different objects for a different purpose

neilyj (No connection with Autodesk other than using the products in the real world)
Did you find this post helpful? Feel free to Like this post.
Did your question get successfully answered? Then click on the ACCEPT SOLUTION button.

EESignature


AEC Collection 2024 UKIE (mainly Civil 3D UKIE and IW)
Win 11 Pro x64, 1Tb Primary SSD, 1Tb Secondary SSD
64Gb RAM Intel(R) Xeon(R) W-11855M CPU @ 3.2GHz
NVIDIA RTX A5000 16Gb, Dual 27" Monitor, Dell Inspiron 7760

Can't find what you're looking for? Ask the community or share your knowledge.

Post to forums  

Rail Community


Autodesk Design & Make Report