Dynamic Block Grip Management

[Jake_PCH]

Dear  Autodesk Community,

The linear grips I am using to establish stretch functionality in a dynamic block are vulnerable to displacement once stretched in model space.

See pictures that help illustrate this.

Any advice on managing the grips and basepoint to ensure they stay locked to edges or a vertex?

Kind regards,

Jake

[rwrightWMDSY]

Try setting the parameter based on the base point  (the center point of the rectangle).  In other words, 4 parameters instead of 2.  Then apply the stretch action to each one.  Your base point and stretch points will remain centered on the object.  

[Jake_PCH]

Thank you for your reply.

I have tried what I believe you are referring to but am not having any luck. Could you clarify with screen shots, please?

To clarify my end, I am wishing the maintain an association between the polyline/hatch perimeter and the grips, & basepoint circled in the attached image.

[R_Tweed]

It's easier if you include your block so that changes can be shared.  I've attached a basic block that has the grip actions working the way you describe.  The trick is that the second stretch has a distance multiplier of .5 and only affects the linear parameter. Take a look and see if this works for your condition.

There is also a group dedicated to dynamic blocks under the Autocad section for you to check out.

[Jake_PCH]

That's really helpful, thank you.

However, it does not solve the issue of the base point becoming disassociated with the geometry. Is there a way of applying an Action or Constraint to resolve this?

I have attached the block for reference.

[R_Tweed · Accepted solution]

The insertion point is fixed.   You would need to move all of your shapes and parameters to work around that point.  I've attached a modified version of your file as an example.  

As an alternative, you can work from a fixed corner and use less parameters. I've attached an alternate file that I use to determine structural tributary areas. I think both will work in the end. I find it best to use the least amount of parameters and actions as a matter of practice. 

[Jake_PCH]

Thank you very much. I hope to pass on your efforts in the future!

[R_Tweed]

The space object might be an alternative to consider based on the block shown.

ACA has space objects that will attach to geometry and updated dynamically, have volume as well as materials assigned.  Tags can be made and attached to the space as part of an insert as well. Once a tag is anchored the style of the tag can modified or changed to another style OR a different label can be used for different display types.