Inventor Hung/Crashed related to AutoCAD geometry?

[DaveC_]

Hello, I am hoping the community can help with this issue. I have been having many issues and I believe they are all related to imported AutoCAD drawings. 

I am running Autodesk Inventor Professional 2014 64-Bit Edition Build 246 Release 2014 SP2 Date: Fri 04/11/2014. Unfortunately, due to the policies of the company I work for, I cannot attach the effected part file for your diagnosis. I apologize for this, but, there isn't anything I can do.

I created a 3D part in inventor based on AutoCAD drawings. My first issue was with importing the AutoCAD drawings. It did go as it did normally, i.e. selective import was not available. Inventor hung when trying to import the geometric constraints from AutoCAD. Therefore, I settled on importing the entire AutoCAD drawing without constraints. In addition, I preserved the AutoCAD blocks. I.e. my AutoCAD blocks became Inventor blocks. I did submit a request for help for this which is located below:

http://forums.autodesk.com/t5/inventor-general-discussion/inventor-2014-cannot-selectively-import-au...

Now these blocks are quite complex, i.e. lots of lines! I simplified the blocks I was going to use by editing the blocks and placed them into a sketch. I build up my 3D geometry referencing these blocks. The performance was always slower than normal but usable, However, as my 3D geometry got progressively more complex, the performance dropped further and further. Then some operations were taking a really long time, or, effectively hung the computer. i.e. a some particular trim commands might take over 4 hours to a day to complete, rather, than a couple seconds as it should. I believe there was a problem with the trim command because this freezing behaviour happened, therefore, I submitted this help request:

http://forums.autodesk.com/t5/inventor-general-discussion/trim-command-bug/m-p/5290085#M522363

The performance issues were getting progressively worst as I added features. It is currently taking over 30 seconds just to place a dimension in a sketch. Inventor seems to have a lot of processing to do for each and every command. I recently discovered that the full drawings I imported initially were still contained as blocks in my Inventor part file even though I only use a subset of them. This part file is 24 megabytes. I started to think that I could improve performance by eliminating these recently discovered unused imported AutoCAD blocks. However, I have found that they take so much time just to delete i.e. days that it isn't an effective solution. I seem to be caught in this conundrum. I invested about 3 weeks of solid time into this 3D geometry, but, I am not finished and I cannot seem to simplify the file to retain enough performance. I have even moved the EOP marker up in the tree to where there is no 3D geometry and just these imported 2D blocks, in an attempt to reduce the computational demand however, Inventor is still hanging. Here are some screen shots of task manger showing the state of the computer after giving a command to delete the blocks. I hope that someone can help me with this.  

I am attempting to use create a derived part that doesn't include these blocks and work with this, but, this creates another mess.

[salariua]

I am experiencing a big problem with imported geometry. I clean the Autocad drawing as much as possible (use flatten command at the end) and import one block at a time, each in it's on part.

We are having 3 months old work stations with K5000 video card and I realized that having visible sketches (autocad imported or not) as well as viewing the model as hidden lines kills it all.

Do you really need to have the whole 3d geometry in one part (that's what I am reading in your post) ?

You cold have them as separate parts with absolute origin constrained by it, in the assembly. It is easier to work with level of details and design view representations in the assembly.

At the end you could do a shrinkwrap if you need it all in one part (batch schedule or not).

[DaveC_]

Thanks for your reply.

I am creating the geometry for a part in a single part file because it is physically a single machined part. The suggestions regarding assembly techniques here, i.e. shrinkwrap etc.. doesn't apply. In addition, all my sketches are invisible and I generally don't view hidden lines, i.e. I use shaded with edges shown.

I will attempt to clean up the autocad file next time then use the flatten command next time before import into Inventor although, I have to have multiple blocks per Inventor part file for my projects.

The 2D geometry that I believe is causing the issue is in the form of "inventor blocks". Most of them have not been placed within a sketch. They are simply in the file avaliable for placement. When I try to delete these unplaced blocks my computer is taking a long time to delete them. In some rare cases it succedues after several minutes, in most others cases in seems to be stuck processing for hours or days. I give up sometimes and just kill the Inventor process.

[ChrisMitchell01]

Hi Dave,

I don't know that it'll make any difference, but have you tried installing update2 for SP2 ?

If you can send me some examples which cause the issue we can investigate, but without any samples that will be difficult.

Thanks
Chris

[salariua]

I don't think that flatten will work on your case because it's used to removed overlapping entities like lines arcs and points. I don't think your blocks will have that many (maybe none) overlapping entities.

Could you be making a simpler version like half and them mirror it? Leave fillets and chamfers to right at the end if possible (maybe bellow EOP)

[DaveC_]

Hello,

SP2 is already installed. I installed it the moment it was released.

Thanks.

[DaveC_]

Hello,

I can't use mirror because there the object(s) have no lines of symmetry.

In addition, Inventor hangs even when the EOP marker is set right at the top, i.e. one one simple sketch is active all the rest is not considered. This is a fundamental problem with Inventor and its handling of blocks and is not related to my geometry. All I am asking inventor to do is delete some imported blocks I am not using. My 3D geometry doesn't depend on them. They are just having this parasitic effect on the rest of the file contents.

Thanks for your reply.

[salariua · Accepted solution]

When I have a large layout I don't copy the whole drawing in Inventor. I open a new dxf file and use that as my transition. 

Copy one block at a time (the one you need current) in the new dxf and import it. 

I use dxf because the file doesn't need to be closed to be accessible by Inventor like in the dwg. So you could leave the dxf open and keep deleting and pasting new geometry for import.

[DaveC_]

I will definately be more careful about how I import 2D drawings from AutoCAD from now on, i.e. I will follow your advice.  However, I have to deliver on this project as my job depends on it.  Therefore, I have an immediate problem  of a file I have invested a lot of time in and I am no longer able to continue using it.

I am hoping there is a way to recover my work at this point. 

[salariua]

Don't have one sketch with all the geometry as well. Try and have as many needed (one per feature ideal). When creating new feature, I found that it can hang on geometry selection if you are pointing at the same sketch. The more features you have the slower it is to select sketch profiles from the same shared sketch.

[DaveC_]

Hello,

Yes, I do model that way. I try to keep my sketches as simple as possible and create features from them. What I was refering to was the EOP marker is right at the top of the list, i.e. as far up as I could make it, which is right on the first sketch. But, below my EOP marker, are many sketches, i.e. over 100 and associated features.

Thanks.

[salariua]

That's a big file.....

Are you machining a whole submarine out of one piece ?

Edit:

The Idea of having level of detail has been accepted, if only you could wait till it gets implemented .

[DaveC_]

Yes, it is a big file.It is not a submarine. 

No this is a simple little box housing that is meant to contain some electronics circuitry. It is a box with several pockets and some groove for EMI gaskets. The 3D is not complex at all. However, the complexity of the geometry is irrelevant because I have rolled back everything using the "End of Part" marker such that they only active stuff are these imported autocad blocks.

What I believe makes the file large is the large complex blocks that were imported from autocad. This is a side effect of the *.dwg selective import feature being broken. I should have cleaned up the drawings in the way you suggested before import. What I did was import an entire AutoCAD drawing into a sketch then delete what I didn't need. I preserved the AutoCAD blocks during this import, so they were stored even though I deleted them from the sketch. I didn't realise this until now. i.e. that they were not deleted and instead stored as blocks. This blocks are not placed in any sketch, but they are sitting there taking up space and they are also potentially causing slow downs.  I literally have a bunch of useless blocks in my part file I can't delete but make it so that I cannot continue my work due to performance issues. This is extremely annoying and dissapointing.

[salariua]

I see some people liked the dxf transition idea. I'll share another one:

If I am importing some small geometry i don't even bother doing the dxf. I just do CTRL+SHIFT+C (copy with base point) in autocad and paste in my Inventor sketch.

When doing sales proposals I skip dimensioning and constraining the imported geometry but I do change it into a block (layout tab on sketch - not visible by default)  so that I can move it around without it exploding all over.

If I were you I would restart the part. The drawing might not compute at all at this stage (give it a try before you go any further)

[DaveC_]

Hello,

Has the .ipt file format specification been released or is this proprietary to Autodesk? It occurs to me that a utility could be created to delete the troublesome blocks from the file.

Dave

[DaveC_]

To recap the issue... I have an inventor part file that is associated with very poor inventor performace. The 3D features are not complex but represent a lot of invested effort on my part. However, they overall performance seems to be effected by the large amount of imported (from AutoCAD) 2D blocks that are not referenced in the file. i.e. they serve no purpose. Deleting these blocks seems to be the obvious solution. This is possible, but, is extremely slow. I was able to leave the computer running over a weekend on the task of delelting a portion of these blocks. It was succesful and after saving the result my part file was reduced in size from 19MB to 15MB. I estimate that only  2.5MB of this file useful data, i.e. associated with the 3D model. I may succeed in resolving the issue, however, I estimated (if the preformace is linearly related to the amount of information to delete) that it will take 150 hours of computer time to delete the remaining blocks. It really doesn't make any sense to me that I could easily and quicly import this data and have it take so long to delete. In addition, I cannot run another Inventor instance along side the one that is deleting-- it simply doesn't finish loading and seems to be frozen due to the other Inventor process. This is unsual as my computer has only aproximately 40% of its RAM used and 12% of its processor by the Inventor that is deleting. Other software can easily run simultanously with this instantace of Inventor that is deleteing. Please explain this behaviour? Why would one instance of inventor effect the other?

I don't consider this issue resolved as I have not been able to recover my work thus far. In addition, there clearly is an issue with how Inventor is handling this.

[johnsonshiue]

Hi! I am sorry to hear that you are experiencing multiple issues in Inventor. Without seeing the actual files and behaviors, I would have to shoot in the dark. Could you try turning off Quick File Open option in Tools -> Application Options -> File?

If it does not help, I would like to take a look at the part. I think I should be able to figure out where the problem is by looking at the file. You can send it to me directly (johnson.shiue@autodesk.com). But, without the file, there is very little I can do.

Many thanks!

[DaveC_]

Thanks Johnson,

I've turned off Quick File Open option in Tools -> Application Options -> File. This didn't seem to have a big effect. Although, Inventor may be using less ram. However, it is still super slow.

Is there any higher level of customer support for the Inventor product, i.e. other than this forum? I may be able to send the file if Autodesk will sign an NDA with our company-- is this possible?

Thanks

[DaveC_ · Accepted solution]

The issue was resolved by me simply manually deleting the blocks over a period of 3 weeks. This took hundreds of hours of computer time. Inventor obviously is doing a huge amount of computation in situations where it doesn’t need to. There were no dependencies on these blocks to my 3D Part. After deleting the blocks my file size is now around 4 megs. At its largest it was 24 Megs. Approximately 20 megs of blocks took hundreds of hours of computer time to delete. This was not the solution I hoped for. Inventor is really making me struggle to get my work done.