LDD file "noise" and is there anything I can do about it?

[SteamSewnEmpire]

Okay, so I am pretty sure that this isn't just my imagination at this point.

Lately, I've been building some rather complex train models (though these typically are significantly under 2,000 parts), and I have noticed that some LXF files are more, uh, "cranky" than others. And what I mean by that is that these LXF files take MUCH longer to load (on my brand new, extremely fast computer) - like on the order of 30-40 seconds, and have a high propensity for crashing. Moreover, if elements from these LXF files are incorporated into another LXF file, then it has the effect of corrupting the second LXF file and turning it into a slow-loading, frequently-crashing dog, too.

As an example, recently I was building the 20th Century Limited 4-6-4 locomotive. I started with a clean build on the engine-half of the locomotive, and for the duration that I was working on this file, load times were generally 5-10 seconds (at most), and I never experienced a crash. 

When it came time to produce the tender, I decided to import in a one from another, previously-built NYC engine and then steal parts from it (the frame, the trucks, the motor/battery arrangement, etc.). Tenders are not complicated models - they're essentially a box on wheels. All the fancy SNOTing, bent tubes, etc. are in the engine. Yet, the moment I imported this tender, the primary LXF file for the engine went straight to hell. Now, it takes close to a minute to load into LDD, and frequently crashes upon attempted saves. It has taken on the characteristics - apparently - of the tender's (and the the tender's old locomotive)'s file; a slow loader.

And this isn't a one-off experience - I've noticed this pattern before with LDD over the years: where certain files become 'bad performers,' and that any elements borrowed from these files, no matter how small they are, will bog down a new host file. Like, I could take just one truck (a single wheel assembly, or bogie) from that tender, and it still had the effect of completely ruining the host LXF wherever I happened to import it. So any element of a bad file, big or small, seems to have this accursed digital 'noise' attached to it, and brings all of that baggage to another model.

My question is twofold: 1) has anyone else noticed this behavior in LDD? And, 2) if you have, have you had any luck in clearing a 'bad actor' somehow so that the model itself can be safely used/imported without a constant risk of crashing (or loading very slow)? Every time I need to make alterations to this freaking locomotive now, I run the risk that LDD is going to crash upon saving. That's ridiculous - it simply isn't that big a model, or a file, and I don't want to have to continue to deal with it, on this engine or any other project in the future.

[deraven]

This may be totally off-base - and it's been a while since I've used LDD - but I seem to recall something similar with a couple files I was working on.  I had the same thought that they had been damaged in some way after working on them off-and-on for a long time, and what seemed to work for those was copying-and-pasting the model or sub-models/sections from the "bad" file into a new one.  Not importing or adding a file as a sub-model, etc., but actually select parts and ctrl-c in old file and then ctrl-v into a new file.

[SteamSewnEmpire]

6 minutes ago, deraven said:

This may be totally off-base - and it's been a while since I've used LDD - but I seem to recall something similar with a couple files I was working on.  I had the same thought that they had been damaged in some way after working on them off-and-on for a long time, and what seemed to work for those was copying-and-pasting the model or sub-models/sections from the "bad" file into a new one.  Not importing or adding a file as a sub-model, etc., but actually select parts and ctrl-c in old file and then ctrl-v into a new file.

Fascinating. I will try that.

9 minutes ago, deraven said:

This may be totally off-base - and it's been a while since I've used LDD - but I seem to recall something similar with a couple files I was working on.  I had the same thought that they had been damaged in some way after working on them off-and-on for a long time, and what seemed to work for those was copying-and-pasting the model or sub-models/sections from the "bad" file into a new one.  Not importing or adding a file as a sub-model, etc., but actually select parts and ctrl-c in old file and then ctrl-v into a new file.

You're a miracle worker - that fixed everything. So, yes, that would definitely imply that some files within LDD develop some kind of bizarre "hangup" that is directly coupled to the bricks. What a ludicrous design flaw - it's almost like a game with a memory leak, but with a file.

[deraven]

3 minutes ago, SteamSewnEmpire said:

You're a miracle worker - that fixed everything. So, yes, that would definitely imply that some files within LDD develop some kind of bizarre "hangup" that is directly coupled to the bricks. What a ludicrous design flaw - it's almost like a game with a memory leak, but with a file.

Glad it worked!

Yeah, I didn't dig deeper into it at the time, but if you've ever looked at a raw LDD file it's basically XML markup, and I think that over time if you make a lot of changes - especially with sub-assemblies - some of the "formatting" tags don't always get cleaned up and while the file can still technically be parsed properly it becomes bloated and slow to process.

Maybe with Lego's purchase of Bricklink we'll see some of the better features of LDD make their way into Stud.io?  *fingers crossed*

[Roadmonkeytj]

On 1/10/2020 at 7:56 PM, deraven said:

Maybe with Lego's purchase of Bricklink we'll see some of the better features of LDD make their way into Stud.io?  *fingers crossed*

Hope your right ... Currently it's atrocious to work in lol

[TheNerdyOne_]

This has happened to me before, and in my experience it's caused by the "Groups" tab.  I'm not sure how it happens, but sometimes LDD will create new empty groups.  This isn't usually an issue, but over time and as you import more and more files, the number of empty groups grows very quickly as each import brings all of that file's groups.  Eventually it gets to the point where you have hundreds, which causes the problems you mentioned.  I had quite a few files that were giving me a lot of issues before I eventually opened the Group tab by accident and saw the problem.

Copy/pasting to another file will indeed work, as mentioned above.  Another option is to edit the LDD file in a text editor, then simply scrolling down to the Groups section and deleting all of the unnecessary ones.

Edited January 13, 2020 by TheNerdyOne_