Trying to understand Pattern Compute Option: Optimized, Identical & Adjust

[Anonymous]

Working my way through this video.

Fusion 360: Patterns & User Parameters

https://youtu.be/apkUQKNwHIo

I can follow along fine, but my pattern menu has a few more option then what is shown in the just about 2 year old video.

Here are the additional options I see.

Compute Option:

 Optimized

 Identical

 Adjust

I have played around with them a little bit and found that Optimized is the only one that gives me the results I'm looking for as I follow along with the video.

Also tried to Google and YouTube my question, but what little I seem to find still did not make things clear for me.

So at this point I'm trying to understand how these options work.

Any help is greatly appreciated.

Thanks,

[jeff_strater]

Good question, @Anonymous.  These options are really just different levels of optimization when patterning features, with slightly different capabilities.

1. optimized is the fastest.  It uses some internal code that just patterns the faces of the feature.  But, there are some limitations:  The feature faces have to all land on the same face, and there are some cases (the most famous is patterning cuts around a cylinder, where this method fails.
2. Identical is next fastest.  This method just extracts the tool body of the feature, patterns that tool body, then joins the results at the end.  It can handle cases like the cutouts around a cylinder.
3. Adjust is the slowest.  This method recomputes each instance of the feature almost as if it were a separate feature.  This allows you to do things like pattern a feature with a To-Face extent, and have each instance of the pattern compute differently.

If this doesn't help enough, I can put together a quick screencast to illustrate.  But really, I just treat them as optimization options.  I try Optimized, if that fails, or doesn't give me the result I want, I switch to Identical, then to Adjust.

Jeff

[Anonymous]

Hi @jeff_strater

I may understand a little better now.

Maybe if you can explain why in my model if I select Identical and then click ok the component looks just like it did before I tried to pattern the chamfer.

Also why do I get the errors that I do when I select Adjust? 

Would guess both Identical & Adjust just don't apply to how I'm trying to work with this particular model, but I'm not really sure.

It would be great if you could show me in a screencast like you suggested, thanks!

Here is a screencast of the result's I'm seeing.

[jeff_strater · Accepted solution]

Interesting case.  I haven't seen that one before, to be honest.  A couple of comments:

• This case is interesting especially because it disproves what I said above.  In this case, optimized actually is more successful than Identical.  
• The problem with Adjust is a bug.  I'll report that one.  It should not fail

In general, it's not a great idea to pattern features like fillet or chamfer all on their own.  It has to do with the fact that these features are really operating on edges in the model, not on features which have a body of their own, like Extrude or Revolve.

In this particular case, I would avoid the chamfer pattern altogether, and just do the chamfer before the cutouts.  Here's a short screencast showing this:

As to the other feature types, here is another screencast.  The first bit just shows that I can reproduce the behavior you are seeing, so I will report the Adjust bug.  The second part shows a difference between Optimized and Identical.  With Optimized, you only get one row of instances of the pattern, but if you choose Identical (or Adjust), you get all 9.  The third part illustrates Adjust.  This is a to-face extrude that I pattern.  With the type set to Optimized or Identical, you get identical instances.  However, if you switch to Adjust, you get each instance of each pattern computing its own extent based on where it intersects the target component.

Hope this helps further clear up these types

Jeff

[Anonymous]

"In this particular case, I would avoid the chamfer pattern altogether, and just do the chamfer before the cutouts."

That sounds like a great idea and makes a lot of sense.

Seeing your screencast made it all very clear for me now, thanks a million!