topic Re: Field - area calculation, solid and void in AutoCAD Forum

Field - area calculation, solid and void

jeanette — Tue, 10 Sep 2024 10:48:32 GMT

Hi,

I'm trying to create a dynamic area calculation (that needs to change on a regular basis) that has two solid areas I'd like to calculate but excluding a void. I'm using "insert field', click the object and so on, but I'm uncertain how to identify the void. I would ideally avoid converting the enclosed area polylines into a block. Anyone able to help?

Re: Field - area calculation, solid and void

tramber — Tue, 10 Sep 2024 12:06:12 GMT

I am a little lost...

What function do you use ?

Do you use MEASURGEOM and its options to cumulate ?

If you need to know an area of 2 separated surfaces, you may use regions ? Do you know them, easy to treat with boolean operations ? You can union and substract, what you seem to reach.

Re: Field - area calculation, solid and void

leeminardi — Tue, 10 Sep 2024 14:02:47 GMT

If you are trying to determine the area of a close polyline that has voids within it defined by closed polylines try the AREA command as follows:

area [enter]

A [Enter]

O [Enter]

select the outer polyline [Enter]

select the polylines that define the voids

You will see a running total of the resulting area.

Re: Field - area calculation, solid and void

AllenJessup — Tue, 10 Sep 2024 14:23:40 GMT

You could covert the area boundary and the void boundary into Regions. Then Subtract the void area. This means you'll be left with a Region instead of Polylines. But the Region will still be editable. The area inserts as a Field with no problem. I've used this method for years.

Re: Field - area calculation, solid and void

paullimapa — Tue, 10 Sep 2024 14:37:22 GMT

Assuming you have an outer PLINE and an inner PLINE that represents the VOID:

In the FIELD window under Field names on the left column select the Formula.

Then in the Formula window in the bottom right column right mouse click and on the cursor menu select Insert Field:

On the 2nd FIELD window that appears on top, go ahead and select the Outer PLINE object and then the AREA property and click OK:

You'll be returned to the original FIELD window and this time in the Formula box next to the first inserted value enter a (-) minus symbol to represent subtraction:

This time on the 2nd FIELD window that appears on top select the inner PLINE that represents the VOID and the AREA property and click OK:

When you're return to the original FIELD window this time click on the Evaluate button and you'll see the Preview showing the subtracted area:

Click OK and you're ready the insert this as a FIELD value. When the outer or inner (void) PLINE changes, the FIELD will update automatically after a REGEN/PLOT/ETransmit commands and etc with FIELDEVAL set to 31.

Re: Field - area calculation, solid and void

jeanette — Tue, 17 Sep 2024 11:09:57 GMT

Thank you so much! I wasn't aware that you could insert formulas within fields. This helps me immensely 🙂

Re: Field - area calculation, solid and void

paullimapa — Tue, 17 Sep 2024 11:15:21 GMT

Glad to have helped…cheers!!!