Discrepancy in object sizes

[wasteofspace (Jeremy Willson)]

Hello
I was messing around with LB and I made a shape with 6 sides and set width and height to 188mm in the tool bar. The shape properties window shows this as 188x217.084
I changed the properties to a four sided figure.
The shape properties box did not change, but the toolbar now shows the shape as 132.936x153.501mm and the measuring tool confirmed these sizes.
Am I doing something wrong?

[berainlb (PY)]

I think what you’re describing is answered here:

Triangle dimension in polygon tool

Ah, in that case I think you’re dealing with something else. Polygon sizes are not exactly the same as edge-to-edge geometric sizes. They reflect the calculated size of the ellipse that encircles the polygon. So orientation of the polygon will affect its geometric width and height but not the shape properties width and height.

[wasteofspace (Jeremy Willson)]

oh, ok, but when i changed the figure to an oblong, should the program not have recognised this and shown correct measurements accordingly?

[berainlb (PY)]

I’m not following. Are you saying if you elongate the shape using the selection nodes that shape properties would also reflect the change? If so, it should do that correctly as long as the other condition I list in the referenced Topic is met.

But as far as your original question, you can see the effect of the difference in measurement approach by increasing the number of sides of the shape in shape properties. As you increase the number of sides, the size shown in numeric edits toolbar will begin to converge with the size shown in shape properties. This is because numeric edits toolbar will always show you the geometric size of every displayed object, meaning the visual size of the object from edge-to-edge. In contrast, the shape properties window is showing you the nominal size of the primitive polygon shape. Note that the size of the shape in shape properties does not change based on the number of sides of the polygon. For polygons, the size reflects the size of the ellipse that fully inscribes the polygon.

[wasteofspace (Jeremy Willson)]

I didn’t use the nodes to change the shape, but rather from the shape properties box. to be only four sides rather than six or whatever.
So, make the initial shape with the polygon tool
Open the Shape Properties window and change the shape to a four sided figure in the properties window.
From here, I would have expected to get a shape of a square that was 188x188 (the original size specified), both on the toolbar and also in the properties.
This didn’t happen.
Instead, the properties showed an oblong 188x217.084 and the toolbar showed a figure that was now 132.936x153.501
Don’t waste too much of your time on this, I was just experimenting and then wondered about the discrepancy between the two sizes shown for the square.
My head hurts.

[berainlb (PY)]

@wasteofspace

From here, I would have expected to get a shape of a square that was 188x188 (the original size specified), both on the toolbar and also in the properties.
This didn’t happen.

I think you’re not full appreciating what I’m describing.

Try this:

1. create a polygon
2. change the number of sides to 4
3. set size of polygon to 100x100 in shape properties
4. create a circle
5. change the size of the circle to 100x100 in shape properties
6. position the circle on top of the square
7. note that the circle goes around the outside corners of the square

[wasteofspace (Jeremy Willson)]

Thank you. I think that I understand it now.