The prerequisites have changed, Dependency-0002

[[Mi...]]

Hello all,

I am new to using the software, and I am experiencing issues with one of my project templates. I have a template setup to scan an airfoil stator, then polygonize, and then perform an 'original alignment as initial alignment', 'local best-fit' and finally a 'coordinate system alignment' that is dependent on the local best-fit. The coordinate system alignment was created by constructing a datum system and various constructions (planes / circles).

What you see in the attached screenshot up above is the properties tab of the polygonized mesh that failed to automatically begin polygonizing at the end of my scan routine, and I believe I've tracked the issue down to this 'The prerequisites have changed' error. I've tried searching the forums for this error, but I am unable to find any information. 

I am wondering if my constructions (the planes / circles) and the order in which I am applying them relative to the various alignments is influencing this behavior. I've also been struggling to understand how project templates behave in general.

Can I please get some help with the issue I am experiencing, and maybe a run down of how I can expect project templates to behave in general? I've tried looking through the Tech Guide, but I have not been able to find something that helps with my understanding.

 

Thanks,

Mike

 

[[Mi...]]

Some more background information:

- I am not running in KIOSK mode.

- My 'local best-fit' alignment is based on three uses of the 'Select Inside Sphere' mesh selection tool. I've attached screenshots of how these inside sphere selections are setup (which is supposed to use my nominal CAD geometry).

• 'A1 B1 C1' is a circle feature construction that has the 'Project Offset Section' measuring principle. This is repeated at a second location for 'A2 B2'.
• 'A3 Point' is a simple point construction that comes off of the 'A3 Plane' which was made as a 'Auto-Plane (Nominal)'.
  • A3 Point has the measuring principle 'Project Point onto Actual'.
  • A3 Plane has the measuring principle 'Fitting Element'.

Is it possible that there is some dependency being made with these constructions that is preventing my project from auto polygonizing and then applying my alignments? 

Edited February 1

[[Mi...]]

Oops. The last image up above is incorrect. It should actually look like this (without that person shaped symbol). 

Edited February 1

[[Je...]]

Hey Mike,

In your first post you describe that the polygonisation did not start automatically and therefore you do not get valid results.
In the first image you can also see that not all calculations in the project have been completed. As you can see, you have the circular arrow in the information area of the current mesh. This indicates that a recalculation is missing (equivalent to a valid polygonisation).
Unfortunately, in your second image, you cannot see the entire status bar. But I assume that the calculation of the actual mesh is shown in red. If you switch to the Project Guide, you should be offered solutions for a valid project.

If my interpretation is wrong and the project is still not calculated correctly, please feel free to contact your local support and share this project. You are also welcome to refer to this forum thread.

Hope this helps, Jens

[[Ti...]]

Mike,

I don't fully understand your problem, but we will get that error inside programs created to measure our meshes. 

That specific error is typically because there is a 'required alignment' problem inside the program. For instance, say you have a section cut with an alignment set to 'Prealignment', then a line from the section cut is created and somehow is set to alignment 'LOCAL_TOP'   This can cause a calculation error and we get that message. I'm pretty good at finding these conflicts fast, but if you have access to 2023 there is a tool to analyze required alignments that can expose these conflicts quickly.

[[Mi...]]

Thank you for the reply Jens and Tim! Sorry for any confusion in my original posts. I botched some of the posts and was unable to edit them after the fact, but it seems you caught on to the issue I am experiencing.

----

I also reached out to Capture3D and it seems that my issues might be what Tim is describing. Some of my constructed geometry was incorrectly linked to alignments that are used downstream in the project.

We don't have access to 2023 (yet), but it may be something that we update to sometime in the future. The tool you describe sounds useful.

[[Ti...]]

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  Glad you got it sorted out. 1st let me explain that I love the GOM software. It is amazing. I enjoy firing it up each morning. I only deal with metal so I cannot imagine the issues with other materials and other scanning techniques.

That said, I 100% disagree with the GOM team that section cuts should not have an alignment tied to them automatically. I cannot imagine a situation in which you would not want a section cut to be in a proper alignment.

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has tried to explain that, but if there is a reason it would be an exception to the rule and one in which you would turn the feature off instead of catering to that odd situation.

That may not be your specific issue, but what I am saying is over time you will learn what features get assigned alignments automatically and what features don't....for instance a cylinder, plane, cone, etc get assigned an alignment by default to whatever alignment your are in. A section cut will not get an automatic alignment assigned. If your section cut is not assigned an auto required alignment then the line created from said section cut will not get an alignment, but if you select a required alignment for the section cut then the auto line created will inherit the alignment.

The section cut alignment may not be your issue...but the same issue applies, you are in a tangled web of parent child relationships, but from my years of CAD experience I've had to parametrically set things to alignments that I don't think should be set...I'm fixing a lot of legacy programs that were not done properly so I'm a little jaded on the whole required alignment deal. In my case, all our legacy programs are over-constained and that is a constant problem that I have to fix.  If distances are done correctly you don't need alignments for distances is my advice.

 

 

 

[[Mi...]]

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 Really appreciate your replies. It's helping me to start piecing together what is going on. The issue is still on-going, but I think I'm on the right track to getting it sorted out. The software is definitely very powerful/versatile and fun to use. I'm thankful that I have an opportunity to work with it.

Can you confirm if the attached images is how you go about updating alignments and try to manage the parent-child relationships? I'm not exactly sure of how/where to control what is dependent on what.

Edited February 9

[[Ti...]]

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  Yea that should do it...you highlighted all the green(actual) elements and then you can use that dropdown next to 'computed in' to change alignments.

 

I'm on 2021 and some of our workstations this doesn't take...meaning you do the right steps but once you refresh it won't change them. In this case I activate the alignment I want in the upper right of the software and make it active, then I open up the actual feature and edit it, then click OK to close it....seems stupid, but what happens if you ever edit a feature and you are in a different alignment that what it was created in it will inherit and change to the active alignment.

I cannot stand this auto inherit feature AFTER you have already created the feature. The first time you create a feature we all WANT it to inherit the current alignment otherwise you would have to manual do this...BUT the moment you have created a feature it should maintain that alignment unless you go out of your way to change it. Your initial alignment should be 'sticky' it shouldn't be easy to undo. Instead it is the opposite, changing it can occur if you are not paying attention.

And build a mental note of which features take on an alignment automatically...planes, cylinders, cones, etc....but section cuts don't, but they should 😉