Bug: Pattern on path

[Anonymous]

Modifying a feature in the history before the pattern on path results in a change in the value: Starting Point which results in a huge modification of the feature pattern on path.

Please stop the modification of the starting point whenever I change the feature before.

Thanks

[pawel.potyrala]

Hi @Anonymous,

thanks for posting! I tested Pattern on Path on a sample path, using a Box as the Feature distributed along the path. I set a particular value to the starting point. I later made changes to the Feature (resized the box) and it did not result in the change of the starting point value.

Could you clarify your workflow and provide us with a short Screencast presenting the issue? Thanks a lot in advance!

Best regards,

[Anonymous]

Hi Pawel,

I created a design I can share (the orginal one is confidential) where the bug shows up:
https://a360.co/2Ts0zD4
PW:
APWorks

When you change the thickness of the Thicken feature (e.g. to 1.2 mm) the pattern on path feature is updated wrongly.

Best,
Niels

[pawel.potyrala · Accepted solution]

Hi @Anonymous,

thanks for bringing our attention to this. I could reproduce the behavior with both your model and another sample design I created based on it. There are some inconsistencies in the creation on the pattern on path, which I am logging in with our development team.

The behavior you described can be considered as expected, though - I will explain it below.

When using Pattern on Path on a Body, the "0.00" Starting Point is the point at the projection of the center of mass of this body onto the chosen Path:

"0.00" Pattern Start Point

Once the body distributed with the use of Pattern along Path is edited and its center of mass changes, the original Start Point of the Pattern along Path feature keeps its original position, but its value is adjusted to reference the new center of mass.

For this example, I changed the thickness of the body from 10 mm to 20 mm. The projection of its center of mass moved by x = 0,43 mm, which gives a Start Point value of approximately 0,002 on a path length of 207 mm.

Thickness changed from 10 to 20 mm, Start Point remains, but its value changes

If Pattern on Path leads to undesired results due to this behavior, the solution for now is to manually set the Start Point to the desired value. As mentioned, I will submit it to our developers for consideration.

Thanks!

Best regards,

[Anonymous]

Hi Pawel,

maybe another thing that would help then to make Fusion update more consistently is to make the Start point input available as a user definable parameter.

Thanks,

Niels

[Aelinon10]

This "center of mass" approach is incredibly abstract and while it is referentially accurate "behind the scenes", as the designer I have no visibility nor control of it.  I've recently encountered it including the component origin as part of the center of mass evaluation, which is beyond irritating.  I would ask that Autodesk consider fully revamping this to simplify it and make it user selectable.