Peculiar behaviour of double lookup

[TomHia]

Hello,

AC2021.

I've run into something I can't really understand and I'm hoping someone could take a look and explain it to me.

Attached is a block. Please don't mind its complexity. What's interesting is the double lookup on the left in combination with "Distance1", "Distance2" and "Angle5" Parameters highlighted here:

What it's supposed to do?

When Angle5 handle is rotated in 90 deg intervals the small circle+line at the starting ends of DistanceX Parameters and "NR_STANOWISKA" attribute should be set at a specific place according to the lookup table (in further steps the attribute should be rotated to a specific value but we'll disregard this in here).

What is the issue?

When you use the handle the geometry in question AND the starting points of both DistanceX Parameters are moved to the left and bottom by the Distance value specified in the parameters:

I'd like to understand why is that the case? Why both Distance parameters' starting points get offset in this situation and is there a way to prevent* that? 

*By "prevent" I don't mean to just offset lookup table values. I mean to prevent parameters being offset in the first place.

[Libbya]

...double post...

[Libbya · Accepted solution]

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@TomHia wrote:

What is the issue?

When you use the handle the geometry in question AND the starting points of both DistanceX Parameters are moved to the left and bottom by the Distance value specified in the parameters:

I'd like to understand why is that the case? Why both Distance parameters' starting points get offset in this situation and is there a way to prevent* that? 

*By "prevent" I don't mean to just offset lookup table values. I mean to prevent parameters being offset in the first place.

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When the rotate grip is used, the Distance1 and Distance2 parameters are set to the distances that match the row of the lookup.  That is how double lookups work.  I don't see anything peculiar about it.

The Distance1 and Distance2 parameters are initially drawn as 500 units in length.  The two values given for them on the table are: 0, and 750.  If you want the Distance1 and Distance2 to match their initial lengths when Angle5 is a specific angle, then either add their as-drawn distance to the double lookup table that matches the row that matches that angle OR adjust their as-drawn distance to match a row on the table.  They will never return to a distance of 500 units as the block is currently constructed because that value is not anywhere on the lookup table. 

[TomHia]

Hi Libbya!

Thank you for a quick reply.

Now that I think about it after a couple of hours and your reply it's obvious...

I must've gotten so much used to centered geometry in recent days it altered my understanding of the parameter. That or a short circuit in my brain, don't know 😅

[Libbya]

If those two distance parameters are only used for moving the attribute/circle, you might consider using a point parameter instead and simply inputting the desired X,Y coordinates into the table instead.  

[TomHia]

That's an interesting take on the matter. I'll try it out tomorrow, thank you!