Creating cross sections from meshes and 3Dfaces

Nuno Gouveia

 Hi,

I'm modelling and urban section for a residential projet and I now have the full model in a mix of 3D Solids and 3Dfaces. I find that 3DFaces are better to model the landscape parts and irregular surfaces; and besides these were generated from a survey cad drawing.

After a lot of "googling" I've found these different approaches:

1) 3DFACE slicing software like the legacy TAILORS (http://polyface.de/). I would be nice if someone portes this to current Bricscad (I've tried it in V11 and it didn't work)

2) converting the 3DFACE into 3dmeshes and converting these into 3Dsolids, again using 3rd party software - tricky and buggy

3) converting  the 3DFACE in polylines (using Rakesh Rao's code  (https://forum.bricsys.com/discussion/18911#18917) and then converting these into REGIONS and finally using 3Dsolids funciotns to section and visualise the wanted view...The problem is that I'm not able to convert severall  POLYLINES into REGIONS, I'm can only do it one face at a time....(I'm using V11). Does anyone know if more recent versions of Briscad can do better?

4) I've also to tried  using BLENDER to create the sections and then export these to Bricacad, but so far with mediocre results (dispite BLENDER beeing an awsome  3D package)

All approaches are so far tricky or too difficult.  I welcome other solutions. 

Thanks for any answers,

nuno, from Portugal

James Maeding

Hi Nuno,

I wonder if you gave the 3d faces a thickness, so made solids from them. Then draw a huge box, with one face as the section plane. Then subtract that box from your solids.

Or I wonder if you can use clipping planes. I also have a similar need to yours, but I have control over the data generating the solids, so tend to revert to that for things like pipe crossings. The 3d face cutting is not to hard to automate, unless you have like 100k of them. You loop through each one and do interpolation to cut the 3d face, then draw each line resulting from the cut.

Maybe we can sell our stuff someday, it has allowed us to use bricscad instead of Civil3d, but we did not give up surfaces, alignments, and grading objects.

Nuno Gouveia

 Hi,

With Bricscad (V11) I can't extrude 3dfaces nor make them regions .  

The TAILORS program would be the best choice.

But I can extrude polylines...  thanks! 

It's still a complicated system - extruding to 1mm and then making sections from the solids

but I'm closer to my goal.

Thanks again

nuno

Jason Bourhill

In BricsCAD V16 you can convert 3DFACES to an ACIS Surface. Steps are:
3DFACE -> REGION -> DMSTITCH to join and convert to an ACIS surface.
BricsCAD V16 includes some tools for working with surfaces. I assume that more tools will be added in the future.

In regards to the TAILORS program. This looks to be a collection of LISP based utilities. It should be relatively trivial for them to 'port' to BricsCAD. Most likely all they need to do is utilise the Bricsys encryption tool to package their LISP. BricsCAD won't run LISP that has been encrypted for AutoCAD.

If your doing this type of thing a lot, then you will find a Civil Design application will pay for itself very quickly. You will find a number of these in the applications area of the site.


Regards,

Jason Bourhill

CAD Concepts

Nuno Gouveia

 Thanks for such a quick answer.

I can convert 3dfaces to REGIONS in V11 but only one at a time, despite de command reference indication that a set of elements could be selected.

As for Tailors, after a few more attempts I just got it to work, but it only sections the faces and we have to trace de resulting profile conneting all the loose trimmed edges.

As for buying an applicatin, I don't do this kind of work that often, but I'll look into it.

Thanks

James Maeding

where is the tailors lisp files? the link in first post did not go to it.

I can make the lisps work if they are uncompiled.

Patrik Sparrman

And also If you are working in 3d with V11 its worth every penny to upgrade your Bricscad to V16 as well.