Formula Driven Dimensional Constraints with action parameters?

[spencer.robertsU8DLN]

Is there a way to drive the formula of dimensional constriants off of the value of an action paremeter? I have a block where the action parameter drives the size of the circle, and the dimensional constraints for ang1-4 control the approximate size of the arrowheads at at radius. 

I've learned that the dimensional constraints can't read the value of the action parameter, but when I set up a radius dimenional constraint of the same value, it locks the size of the circle. 

Is there perhaps a 'driven' constraint value that can be used in constraint expressions, or is this just a limitation of the system?

[j.palmeL29YX]

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@spencer.robertsU8DLN wrote:

I've learned that the dimensional constraints can't read the value of the action parameter,

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That's right. You can not mix dimensional constraints with action parameters. 

Unfortunately I do not yet understand what you want to achieve. Which parameter do you want to drive using which formula? Therefore I can show only a base suggestion how you can avoid the need of the dynamic parameters (Distance1 and Position1) and actions (Stretch, Move), nevertheless you can drag the right most point as in your block. Depending on the position of this point the radius of the arc and the position of the gap changes and you can the (calculated) radius for other purposes (in other expressions). 

The only small flaw: Sometimes you can drag the point only in orthogonal (horizontal or vertical) direction. Then you must grab the grip again to drag it to the needed position. 

If you tell us more detailed what exactly is your goal - perhaps I can help more precise to reach your whishes.

[spencer.robertsU8DLN]

My goal is to create this block so that:

1. The user can select a grip center on the text, and rotate the symbol 360 degrees, keeping the text upright, and change the diameter of the circle

2. Maintain a consistent arrowhead size at the inserted block scale for any diameter value  as defined by the following formulas:

3. The center of the block is at 0,0 for ease of future LISP automation.

 

This block is intended to be an upgrade to an annotation symbol we've been using that has inconsistent results.

The modifications you made, as well as some additional ones that I made, are a noticable improvement. I can get intended behavior, but only in quadrant one. It refuses to be dragged to any other quadrant. Any idea why this would be happening?

[j.palmeL29YX]

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@spencer.robertsU8DLN wrote:

 

... some additional ones [modifications] that I made, are a noticable improvement. I can get intended behavior, but only in quadrant one. It refuses to be dragged to any other quadrant. Any idea why this would be happening?

Of course. Exactly your modifications to my block destroy the possibility to drag the point to all 4 quadrants: 

A dimensional constraint parameter (here the horizontal and the vertical parameter d1 and d2)  can never be smaller than 0 and so never been dragged into the opposite direction. Therefore I added a point object where I set the basepoints of the parameters d1 and d2. This point must be placed outside of the largest to expect dimension of the polyline. Even if the text will be dragged to its most left or most lower position, d1 and d2 must have a positive value. Because I did not (and still do not) know which maximal dimension of the polyline (radius) we can expect I added two parameters fix_x and fix_y. so you can easily adjust it to your needs. 

In the here attached new version of my block I only changed the value of the both parameters ang1 and ang3 to your formulas - it should work as expected.

[j.palmeL29YX]

Could you solve your problem in the meantime? Or do you need further help ... ? 

Please mark "Accept as Solution" if my reply resolves the issue or answers your question, to help others in the community.