Pattern Anomalies - Repeatable Crash

[TheCADWhisperer]

Ping

@jeff_strater 

@Phil.E 

Examine the Hole features in the attached files.

Attempt to add the same hole to remaining blank faces.

(Difference between files in Adjust/Optimize one of the earlier patterns affecting the Hole feature.)

Note that the patterns inexplicably and without warning created surface bodies.

(Sure would be nice if surface bodies were obvious - like in Autodesk Inventor Professional.)

Hole AnomalyPattern Anomaly

[Phil.E]

Thanks for the model. The crash is repeatable, fortunately there doesn't seem to be many people capable of achieving the crash.

As for the pattern. The trouble starts by patterning features. Jeff might correct me, but I don't think you should expect the same exact behavior you'd find in Inventor when patterning features in Fusion. In this case it somehow promoted/demoted the feature selection to be a collection of surface bodies. I don't think I've ever seen that, and normally I would assume it would simply fail because the output is not a solid, when in the solid environment. One of the problems is the feature/face for the little nubs is flush (and is one surface) with the side of the box. Fusion does not handle this, it would have to discard most of the face/feature you are trying to pattern.

Should Fusion be making decisions like what faces to discard in the pattern? (in this case the broad faces of the original box) Or should the pattern contain "patternable" geometry? If you make the little "nubs" as bodies and pattern/combine those this should work. 

[Phil.E]

PS: I cannot find one CER with your email address. Either you don't crash, or don't send in CER, or don't use your email address associated with your forum ID. What should I look for to find your crashes with the hole command? I'm asking because the bucket I crashed into has the most recent report as a few months ago. Unless I can find more than one crash per 6 month period, this would be a low priority crash. Perhaps you found a different CER bucket, but I cannot find it.

[TheCADWhisperer]

In Inventor I would generally Pattern Bodies when possible and practical rather than Features, but unfortunately Fusion does not give you the option to Combine them in the pattern feature - it must be Combined as a separate operation.  This drives me crazy and is one thing that Inventor got right over SolidWorks.  Fusion should do the same.

The crash reports should be under jmather_at_pct_dot_edu

but given that you can reproduce...

[Phil.E]

Actually your crashes went into a similar but different bucket for the same problem. It helps to know all the details. Thanks! 

[jeff_strater]

@TheCADWhisperer - this is a legitimate bug.  @Phil.E - one of us should log this bug (not just the crash, the surface body results, so maybe there are two bugs here).

Couple of comments here:

1. yes, Fusion patterns are not yet as robust as Inventor patterns.  Specifically, the Adjust feature pattern does not handle the same set of scenarios as Inventor, especially around feature that interact with the "target" geometry (e.g. blends to the adjacent faces).  The way it's supposed to work, it should be optimized -> identical -> adjust should be increasing reliability at increasing expense.  There are cases I've seen where Adjust fails, and Optimized succeeds...
2. we are planning, later this year, to start a "pattern improvement" project to try to fix some of these issues.  This is good input into that project, so thanks.

[TheCADWhisperer]

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@jeff_strater wrote:
we are planning, later this year, to start a "pattern improvement" project to try to fix some of these issues.  This is good input into that project, so thanks.

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Please add Combine option in Body Pattern.

[Phil.E]

The crash is logged, the surface bodies are listed as a probable contributor and I urged the team to split the ticket if needed.