Model States vs Level of detail - capacity and performance

[RomSyl]

Hi everyone, 

I introduce myself, i'm working for a major oil & gas company who develop offshore oil field.
My dpt work on offshore field development vessels & crane ships.

We run Autocad, Inventor and vault pro as engineering software. Over the years, through our engineering work, through our subcontractors & shipyards models, we have built very heavy 3D models of vessels of our fleet.

LOD appros 25k open documents, 35k occurrences, 16Go / 32 go Ram 

So, through the years we have used Inventor “Level of Detail representations” to manage our models.

Level of Detail representations

This tool was very helpful to keep running heavy 3d models, we spent lot of time to create those models with LOD.

This vessel’s contains lot of movable equipment, we have define hundreds linked parameters for functional requirements using excel spreadsheet Linked parameters

We fully understand the integration of model states, as some of our designers were already using "representation views", in this way. (BOM filter then).

We understand the need of configurable model without "family use".

Model states move the software in another level of use, it development going forward and it looks great!!

What we don't understand, why have you merge "level of detail" used for "improve capacity and performance" in model states? Is autodesk plan to distinguish again between performance optimisation?

The first things. This merger introduces confusion in the use of model states. Part configurations, and/or assemblies, are confused with model states created to improve performance.

Files are heavier.

Express mode seems saved all model state, we can open any model state in express mode. What was not possible before with LOD. only the latest save can be open in express mode. Is this have an impact on files size? 

Thanks.

[johnsonshiue]

Hi! Many thanks for the feedback! It is indeed a bit confusing to migrate LOD to Model States, since LOD is a memory management tool, not a configuration tool. It does not have any ability to alter a design or a property except loading or unloading documents.

If you want the LOD behaviors on 2022 and later releases, I suggest you leverage Copy to Design View Rep workflow before or after migration. In terms of changing an assembly, LOD is very close to Design View Rep (suppressed = invisible).

Many thanks!

[RomSyl]

Thanks Johnson for your answer,

Your suggestion is not an option nor a possibility! Our model are so heavy that inventor is not able to run with all components load in memory... 

We have already migrated from V2018 to V2022 due to "product support lifecycle".

Maybe there is something i don't understand, or i'm doing wrong with model state. The fact is heavy models doesn't run properly anymore.

I could not explain more clearly because i don't understand how inventor code works. I just see my computer running and me waiting.

[johnsonshiue]

Hi! Is there any substitute in the LOD? If yes, there was a known issue that the LOD substitute was migrated with the link unsuppressed in 2022 RTM. As a result, the assembly might be trying to update the substitute when activating a Model State.

This defect has been fixed on 2022.1 update. Please make sure 2022.3 update is installed. For the already migrated files, you will have to manually or use iLogic rule to suppress the substitute link.

Many thanks!

[RomSyl]

Hi johnson, 

There is lot of substitute i can't say how many of them still in old LOD. I will check them and removed them... 

Then we will migrate the LoDs by "copy-paste" as recommended by autodesk, maybe this will improve something?

I think "model state" are not design for heavy models... 

Build: 287, Release: 2022.2 - Date: Sun 10/24/2021  

Thanks for your supports, 

[mpatchus]

This thread is seriously concerning to me, as our library of over 5,000 parts/assemblies all contain multiple LOD for use in our substations.  LOD is CRITICAL for us in order to manage (and in some cases, just OPEN) some of our larger stations with over 500,000 instances of parts.  Have to do some serious investigation before migrating Inventor any further.

[RomSyl]

Hi  

i have a miss understanding of your answer, sorry.

About View representation, it seems according to what you write and what is write on the inventor support web page :

"You can use View Representations in place of legacy LODs to achieve similar large assembly performance improvements. Invisible components are not loaded into memory"

i do a spreadsheet to compare memory use. The document is a structural assembly (a light one without mechanical part), one file is open.

MS or VR Document open Occurences RAM

Principales	926	2346	1.420
VR Detail Suppressed	926	2346	1.265
MS Detail Suppressed	926	578	1.150

You right, View representation, with invisible state, is less system memory usage.

Model state, with suppress state, is a bit better.

But, Model State also manage constraint... View Representation are not explicitly visible in the browser...

So, I am a bit confused... 🙂

From autodesk side, what is the best practice to improve capacity and performance?

From our last topic, i go one removing my substitute.

[johnsonshiue]

Hi! Yes, Model State does manage constraints, while Design View Rep (DVR) doesn't. LOD doesn't either. Based on my understanding, if you like the legacy LOD behaviors, DVR is the closest you can get in 2022 and later.

Many thanks!