Trimesh End Caps

Any questions regarding the practice version are asked and answered here.
Post Reply
Gregory Brett Molloy
Posts: 2
Joined: Wed Apr 01, 2020 12:27 pm

Trimesh End Caps

Post by Gregory Brett Molloy »

I have 2 tunnels that are intersecting. When I use the Trimesh Boolean Operations to trim the trimeshes at the intersection the trimmed trimesh is given end caps...how can I stop this from happening? I have tried the 1 minus 2, 2 minus 1 options (Union is not an option as the trimeshes created are HUGE) and have deselected the Keep Faces button.
Adam Mackellar
Posts: 8
Joined: Mon Oct 22, 2018 11:12 am

Re: Trimesh End Caps

Post by Adam Mackellar »

Are you able to email the data to support@12d.com?
This is most likely a problem with the boolean operation themselves, so you may have to avoid using boolean operations if they are not giving you the output that you expect.
Gregory Brett Molloy
Posts: 2
Joined: Wed Apr 01, 2020 12:27 pm

Re: Trimesh End Caps

Post by Gregory Brett Molloy »

Thanks. I managed by using "union" and unchecking the "keep vertices/edge/face buttons" - made the "merged" trimeshes much smaller in size and more manageable without losing any relevant geometric data. Cheers.
Matthew Monk
Posts: 3175
Joined: Fri Oct 21, 2005 2:46 pm

Re: Trimesh End Caps

Post by Matthew Monk »

Those tick boxes to keep vertices/edge/face buttons will drastically slow down the process, too, since all the vertices/edges/faces have to be re-processed after the merge.

FWIW, for relatively clean and simple tunnel geometry you might get something working well, but I could never get acceptable results from the in-built options on my tunnels. Using solid/closed trimeshes should make things easier if you want to use 3rd party software, but open trimeshes caused problems. You might also get better results temporarily translating things to 0,0 so you don't get a loss of precision, which can often trip up some of these mesh operations.

I still haven't found an acceptable solution that works well enough for me.
Richard Mitchell
Posts: 172
Joined: Tue Apr 22, 2014 11:52 am
Location: Melbourne

Re: Trimesh End Caps

Post by Richard Mitchell »

Generating trimeshes from 12d objects using a drainage network creates three mesh objects on haunched pits. This poses a problem when assigning object IDs which Kevin Sun has touched on in another post.
Trimesh Boolean Operations will 'join' two trimeshes together at a time. Is there a 12d panel that can do this with the general data sources? Filtering by an attribute like unique name and setting the panel to join objects in a sequence by GUID and/or trimesh edge proximity.

Using the current panel in a chain seems too cumbersome.
RMitchell
Arup
paul hardwick
Posts: 1313
Joined: Thu Dec 06, 2007 9:27 am

Re: Trimesh End Caps

Post by paul hardwick »

Try running through service chamber many (no settings needed)
Paul Hardwick
12d Support Qld
Richard Mitchell
Posts: 172
Joined: Tue Apr 22, 2014 11:52 am
Location: Melbourne

Re: Trimesh End Caps

Post by Richard Mitchell »

That is a part of my DNE to strings chain Paul which you have (and gave me the macros for).
You can see the pit string in cyan from the get edges macro runs the full external at the top RL attribute. However it doesn't take into account the top section.
The other issue is the Get Trimeshes from 12d Objects panel creates three mesh objects on haunched pits, where everything else is just the one. I have highlighted the top/middle mesh object.
Haunched DNE pit
Haunched DNE pit
offset chamber.jpg (58.22 KiB) Viewed 149 times
RMitchell
Arup
Post Reply