Sorry Michael, I feel like every few years I bug you about viewport dimensions :(. I am doing some small/medium parts in mm (~2 meter max bounds) and have noticed that when I extrude them the dimensions are changing ever so slightly in the viewport.

I am starting with a relative simple polygon closed curve with a bounding box of 450.00000mm x 842.00000mm, but once I extrude it by 80mm it is becoming a solid with displayed bounds of 449.99997 x 79.99999 x 842.00000. If I click to edit the size I am presented with 450.00000 x 80.00000 x 842.00000 as my starting values, and if I draw a line across the part the line has a length of 450.00000.

I am therefor assuming that this is a display error, is there anything I can do to fix it?

Thanks,
FDP

Hi FDP, are you referring to the size readout in the properties panel in the upper-right corner of the window, that shows up when an object is selected?

That size is obtained from the display mesh bounding box, so it's not going to be accurate to a high number of decimal points. If you set your decimal display precision under Options > General > "Decimal display" to 2 decimal places it would then probably display better in this case.

That size uses the display mesh so it can give a result very quickly - that part of the UI is updated whenever you change selection and calculating an accurate bounding box can be a somewhat time consuming operation. When you click on it though, MoI will do a high accuracy calculation at that time so the result in the popup menu will be more accurate.

I guess probably a good solution would be to do a high accuracy calculation on a background thread so it wouldn't make the UI potentially stutter on every selection change. However, this is a pretty sensitive thing to get right because of things like the possibility of the background thread still processing things while the object is deleted. So it's something that will require a fair amount of effort.

- Michael

Thanks Michael,
Yes, I'm looking at the size readout in the properties panel. I figured it wasn't the actual mesh size, it's good to know a workaround.

Regards,
FDP

Hi FDP, I have an idea that may help with increasing the accuracy of the quick bounding box calculation, I'll give it a try for the next v4 beta and maybe that will help reduce this glitch.

- Michael

Thanks Michael!

Hi FDP, did you see any improvement in this with the last v4 beta?

- Michael