Bug? Model Fill Pattern Orientation, Rotated and Mirrored groups

[ellison]

Model fill pattern orientation appears to get confused when an object is both rotated and mirrored.  See attached Revit 2020 project and screen capture.  This example uses a floor with a pattern of parallel lines.  I have reproduced the issue with both ceilings and soffits, so I assume the problem is related to model fill patterns in general.  This issue appears to go back at least as far as Revit 2016.  The workaround would be to reorient the pattern with Rotate.  However, if the object is a member of a group, this option is not available.

Is this a bug?

[RobDraw]

Here's a tip for you. Don't use the word bug. The vast majority of the times this word is used, it is usually due to user error. Instead, post the issue and let the thread determine if it is a bug.

[Lance.Coffey]

Thank you for the question @ellison.

The following article has information on this behavior:

Alignment of surface pattern is lost after element is mirrored in Revit

To work around this behavior in groups, you could create a separate group definition when one or more of the included elements will be mirrored.

[barthbradley]

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@ellison wrote:

This issue appears to go back at least as far as Revit 2016.  The workaround would be to reorient the pattern with Rotate.  However, if the object is a member of a group, this option is not available.

Is this a bug?

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Sounds to me like you have discovered a limitation and a workaround.  

[ToanDN]

Simply add a ref plane to the group and lock the pattern to it.

ToanDN_0-1599590525323.png

[adminreprtwar]

Can you please elaborate on how to do that?

Thanks

[jseltzer]

I tried this and it doesnt work in 2023. the pattern rotates in one version of the group and stays the same in another version of the same group. is there another way to solve this? 

[bart.koevoet]

@ToanDN I've tried this as well but when you finish the group it just removes the constraint.