Adding "Visibility Set" to dynamic block that has constraints loses constraints on saving - Autocad Mechanical 2025

[stoweiJY4E2]

Hi,

I have both Autocad vanilla and Autocad Mechanical installed, version 2025

I'm encountering some issues using dynamic blocks in Autocad Mechanical. Here's my steps (may not strictly follow this sequence though)

(1) draw the shape in the picture

(2) Auto constrain them all

(3) Add linear dimension d1 and radius rad1

(4) Add a visibility set; above steps are as Visibility State 1

(5) Add a State 2, mirror anything above x axis, and hide anything above x axis.

As soon as I click Save Block, all the constraints will be lost! 

I noticed people mention not to use Action Sets along with Constraints as they may cause issues, does it apply to my case?

However when I try the same thing in Autocad vanilla, there seems to be no issue at all.

Thanks.

[j.palmeL29YX]

As far as I understand your intention I can not believe that it works well in AutoCAD (neither in Mechanical nor in Vanilla). Obvioulsly I misunderstand something. 

Please post your block what you have until now, so I can see what you did and what you want to achieve. 

At the moment I only can say that it is not possible to mirror dimensional constraints. The mirror command  creates two independent shapes, only the geometrical constraint are "copied". To get what you want to achieve (as I understand) you can add some "equal" constraints between the base shape and the mirrored shape. And drive the needed dimensions via the properties window (because the mirrored shape doesn't have grips to drag the dimensions).

[stoweiJY4E2]

Hi Jürgen,

Thanks for your reply. I've attached the test drawing.

Sorry for the confusion, I'm not trying to mirror the dimension constraints, I manually added the other dimension for State 2. But this shouldn't be the critical part.

I just gave it another test to my test drawing block, I have no issue editing & saving the block in Autocad Vanilla; however as soon as I open the drawing block in Autocad Mechanical and save the block in block editor, all the constraints will be gone.

I'm fairly new to using dynamic blocks; I'm not sure whether I'm not using it correctly or there are other reasons behind this.

Thanks.

[j.palmeL29YX]

Do you mean this? 

[stoweiJY4E2]

Hi Jürgen,

My issue comes when I click [Block Editor] - [Save block], a warning message comes up saying geometry not fully constrained. If I click "Save" all my constraints on the geometry would be lost. Please also check the video I attached.

This happens in ACAD Mechanical. Not an issue in Vanilla.

Thanks.

[j.palmeL29YX · Accepted solution]

Now I see what happens. 

In most cases the mix of constraints and dynamic parameters/actions will lead to problems. The problems in Mechanical are caused by the added visibility states. Vanilla AutoCAD is obviously more tolerant here.

[stoweiJY4E2]

Hi Jürgen,

Thanks for confirming this. Before accepting "it is what it is" and closing the thread, do you think this should be raised to Autodesk's attention? Or it is some known issue to them but it doesn't have the priority to be fixed at the moment.

Took me weeks to try everything this in Mechanical only to find out today. A bit of frustrating journey for myself.

[j.palmeL29YX]

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@stoweiJY4E2 wrote:

... do you think this should be raised to Autodesk's attention?

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Of course you can do that, even if I think it is not worth the trouble. But who knows, I'm not god nor a prophet 😉