[b]ANOTHER AutoCAD MODELLING FAILURE!!![/b]

[AutoAngst]

Whilst attempting to join two relatively basic solids, good old AutoCAD 2005 flashed up this old chestnut:

The Boolean operation on solids failed.
Modeling Operation Error:
System inconsistency processing edge coincidence.

Bearing in mind that I had no gaps between my objects as I had been very careful about where my object snap snapped to when i was creating them, and they'd both been created in the same U.C.S. AND I'm using a machine with twin Pentium processors and a Gigabyte of R.A.M., should the error message actually have read:

The Boolean operation on solids failed.
Modeling Operation Error:
AutoCAD mis-sold as having 3D functionality.

??! - Any affordable suggestions would be greatly appreciated,

Kind Regards,

A-A

 

[TCARPENTER1]

Hi A-A,

Here's a few things that have worked for me in the past:
[ul]
[li]Try making the solid deliberately overlap - this usually works.[/li]
[li]In the past, I've actually had some luck just changing my view direction (2004).[/li]
[li]Check and be sure you have all the latest and greatest service packs installed - this can make a difference also.[/li]
[li]If you're still having trouble, try either recreating, or inserting the shapes you're trying to extrude into an empty drawing.[/li]
[li]If you're using polylines, make sure they are closed - this is a common one.[/li]
[li]If you are extruding regions, maybe try converting them into polylines instead.[/li]
[/ul]

HTH
Todd

 

[Occupant]

The only other thing I'd have to add is: may be you are too far away from the Origin. Long distances throw errors into the floating point calculations.

 

[ctopher]

I think the 3D modeling within ACAD is a waste of time and recources. If you want to design in 3D, use SolidWorks Inventor, ProE, UG or CATIA.

Chris
SolidWorks 07 3.0/PDMWorks 07
AutoCAD 06
ctopher's home (updated 04-21-07)

 

[cfee]

The first reply was the best. ACAD 3D is very robust, and quite stable. It's not as much 3D as S-W, S-E, Iv, etc, but I consistently get great results with it. Add to that the excellent lighting and rendering tools, and you can really get some amazing results.

Now to your problem.

Overlapping may actually be the key here, as the post by tcarpenter1 suggests. While later versions handle this particular problem better, what you may be encountering (not seeing your actual model) is a divide-by-zero issue. If edges that are to be calculated to be removed are aligned as EXACTLY as can be achieved by ACAD using osnap, you might be actually creating the problem. I remember encountering this issue at 13 and again at 2000i, but havent seen it since. Apparently 2005 (I skipped that one...) has the same problem ?

Good luck-
C. Fee

 

[AutoAngst]

Dear All,

Many thanks for your thoughts, I can't download any-more service packs here as our firewall set-up is tighter than a nun's proverbial! I was working fairly close to the origin, so in this instance I don't think that this was the problem - though I too have experienced the UCS issue in the past. It's an interesting thought that exact alignment might be the source of the problem, I'll have to experiment further, though I have found that AutoCAD sometimes leaves lines on 3D objects after Boolean ops, which don't appear to represent anything. I tend to take profiles from the 3D objects anyway so it's not too of much of a problem deleting the said lines, just another AutoCAD 'quirk' I imagine.

 

[TCARPENTER1]

Hi A-A,

...though I have found that AutoCAD sometimes leaves lines on 3D objects after Boolean ops,...

Now I'm pretty sure alignment is your problem. These probably aren't lines, sometimes you can actually zoom in close enough to see it's actually a "hole" in your solid. While AutoCAD can work in 3D fairly efficiently, it's not as robust as say a Pro/E, Catia or UG. The latter packages are robust enough to tolerate some "slop" - and would have closed the "hole" in your solid - AutoCAD is not as robust, and has to have a high degree of accuracy or the models (and AutoCAD) can bomb. I blew a big project this way when the models became so corrupt I couldn't make the deadline of my client! You might try the following when working in 3D, change your units to decimal, and set the precision on it's highest setting, for both linear and angle measurements, and make sure you always use osnaps to ensure things "connect" without leaving gaps.

HTH
Todd