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Complex 3D model intoa surface.

11 REPLIES 11
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Message 1 of 12
AndyWalker
898 Views, 11 Replies

Complex 3D model intoa surface.

Hello,

I have created a complex 3D model of a marine breakwater in vanilla Autocad.

How can i change this shape into a surface in order for me to use the volume calculations between this and another seabed surface i have created?

i understand that civil 3d does not cope with 3d models in the same way acad does and that i must tranfer it into something civil3d can cope with better....

please any help or advice is much appreciated.


thanks
11 REPLIES 11
Message 2 of 12
CadKid1
in reply to: AndyWalker

These models aren't 3d solids, I assume?
Message 3 of 12
Anonymous
in reply to: AndyWalker

C3D handles solids the same as vanilla acad.
It creates entities called surfaces that do not act like solids (as you seem to know).

Looking at the volume tools available, you can only get volumes between surfaces, or volumes of solids.
You cannot simply drape a surface over solids, you must make the solids have 3d plines for edges, then add as
breaklines. You might try exploding the solids in 3d wireframe, then erasing linework that is not useful for the "top"
or "bottom" surface. then add that linework to a civil3d surface, and it will triangulate.
Then do volumes as usual with c3d.

the other way would be to trim your solids with a solid created from the seabed surface.
In that case, you would not make the seabed surface with C3D, but acad solids tools that would make a mesh from the
elevation data points.

I'm very interested in this workflow, as solids are what people want to see much of the time for pavement and other
civil things, not surfaces which have no thickness.

AndyWalker <>
|>Hello,
|>
|>I have created a complex 3D model of a marine breakwater in vanilla Autocad.
|>
|>How can i change this shape into a surface in order for me to use the volume calculations between this and another seabed surface i have created?
|>
|>i understand that civil 3d does not cope with 3d models in the same way acad does and that i must tranfer it into something civil3d can cope with better....
|>
|>please any help or advice is much appreciated.
|>
|>
|>thanks
James Maeding
Civil Engineer and Programmer
jmaeding - at - hunsaker - dotcom
Message 4 of 12
AndyWalker
in reply to: AndyWalker

cadkid1 ..... this is the problem.....the seabed is a surface!......but yes the breakwater IS a 3D solid.

james.....

thanks for your reply......yes its seems i have to do one of two things.....create a surface from the solid breakwater.... or change the
surface seabed profile into a solid.
im just trying to decide now which one i feel is easier.....ive got to say im pretty disappointed at 3dcivils terrible interaction with solids but then i guess thats my own fault and something i should of checked out first before diving into this. i suppose id hopped i could of used the solid straight away or even selected one of its faces to turn into a surface etc

i think i will have a look through some tutorials and try making a surface from the method you suggeested by extracting the 3d polylines of the front face and adding breaklines etc.....
Message 5 of 12
Anonymous
in reply to: AndyWalker

Hi,

Does the 3D Solid contain any overhangs or absolute vertical sides?

I work at SoftSoft.net on a program called TopoGX. It would be useful to
know what the breakwater looked like before I could say whether I can
help convert it. Posting the file or a part of it would be useful.

TopoGX is at heart a 3D surface viewer and I may be able to knock
something up to convert your 3D Solid into a surface, but it does depend
on what the input entity is.

Hope I can help
Dave



On 30/07/2009 09:06, AndyWalker wrote:
> cadkid1 ..... this is the problem.....the seabed is a surface!......but yes the breakwater IS a 3D solid.
>
> james.....
>
> thanks for your reply......yes its seems i have to do one of two things.....create a surface from the solid breakwater.... or change the
> surface seabed profile into a solid.
> im just trying to decide now which one i feel is easier.....ive got to say im pretty disappointed at 3dcivils terrible interaction with solids but then i guess thats my own fault and something i should of checked out first before diving into this. i suppose id hopped i could of used the solid straight away or even selected one of its faces to turn into a surface etc
>
> i think i will have a look through some tutorials and try making a surface from the method you suggeested by extracting the 3d polylines of the front face and adding breaklines etc.....
Message 6 of 12
AndyWalker
in reply to: AndyWalker

hi dave,

thanks for your interest and any help you can give.

i have included a version of the breakwater for you to have a look....its not the most up-to-date one as im away from home today.
Tho yes it does include a few vertical sides where i have split the breakwater into sections when modeling.

i was kinda hoping i could effectfly trace the outline of this solid with a surface? can i not say select a whol bunch of point on the breakwater into a surface?


thanks
Message 7 of 12
AndyWalker
in reply to: AndyWalker

james....

just wondering you comment on making a mesh model solid of my seabed surface.....do you know if its possible to use a set of data points as you can in civil 3d for the input of data....my seabed is made up of millions of point and if i had to manually input these rather than have them drawn from a text file then this option is a no go.

thanks again
Message 8 of 12
CadKid1
in reply to: AndyWalker

Andy,



Points, lines, blocks, text, 3D Faces and polyfaces may be used as input for surfaces as AutoCAD drawing objects directly into a Civil 3D surface.

You may have to extract faces from your 3d solid to get this to work.

Right-click on the Surfaces portion of your prospector palette, choose "create surface", name accordingly (this should be a TIN surface). Then expand the options under the surface, then under definitions, right-click on Drawing Objects and follow from there.

Do that for both surfaces, then set up a volume surface using those surfaces as your base and comparison surfaces, respectively.

I find that doing a boundary volume from the volume surface works better than just using the surface volume statistics.
Message 9 of 12
AndyWalker
in reply to: AndyWalker

right nice one...ill give that a bash when im home...

thanks very much!
Message 10 of 12
Anonymous
in reply to: AndyWalker

Hi Andy,

Unfortunately the current version of TopoGX doesn't load 3D Solids. I
may adjust the next version (release date yet unknown) to cope with it.

The main issue is the overlapping surfaces within the file. I'm not
exactly sure whether you want the entire volume or if you want the
volume of different components within the breakwater.

What I did was to load the file, select everything and explode it within
Autocad. This converted it into 'surfaces' and 'regions'. The next thing
I did was to manually delete all items within the structure that weren't
part of the outter surface. Once done, select all again and explode to
convert everything to lines and splines.

I then saved it to DXF and loaded it into TopoGX which automatically
created the surface. I have attached the KML containing the 3D Faces of
the outer surface. For kicks I worked out a volume to the base of the
structure to be approximately 85779.89 mtrs cubed. As a note, I
translated the model south by a few metres to make it visually fit
better in Google Earth.

Instead of the last step, you could save it as an R12 DXF to convert the
Splines into Polylines and load it into Civil 3D and add them to the
surface definition.

Hope this helps,

Dave



On 30/07/2009 13:40, AndyWalker wrote:
> right nice one...ill give that a bash when im home...
>
> thanks very much!
Message 11 of 12
smceachron
in reply to: AndyWalker

There's a good chance a surface created in this fashion won't properly triangulate unless you select "Maintain edges from objects." This option wasn't available in Land Desktop at all, and wasn't available in Civil 3D until 2008.

To work around the issue in older software (or to use DTM triangles created in other software) and force the triangles to follow the paths established by the original triangle edges, turn the 3D Faces into regions using the AutoCAD "REGION" command - regions can be exploded and triangle edges can be added to a surface as breaklines, 3D faces can't be exploded. The exploded regions will yield duplicate lines, but you can use the MAP drawing cleanup tools (MAPCLEAN) to reduce the size of the drawing.

It's the importance of the edges that lead to the "maintain edges from objects" option.

hth,
Scott

Scott McEachron
The I.II.I Consortium
www.121pcs.net
Message 12 of 12
AndyWalker
in reply to: AndyWalker

this is starting to sound much harder than i anticipated!

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