Strange Character in dimensions

[JamesP]

I'm posting here because I think this is a really simple question.

Why do I get a "~" in front of some (but not all)dimensions?

like this: ~ 859.0mm.

Told you it was a simple question - but I can't find the reason.

Any help will be appreciated

[Rich O Brien]

it is to say that your measurement is approximated.

if say the object you measure is 859.0000256mm. Sketchup can only read to .0001 so it will be ~859.0mm

Have you Model Units set under Window > Model Info to the largest decimal values?

[JamesP]

Thanks Rich.

I will not worry about it then - 'cos if I build to an accuracy of 1mm I would be more than happy - indeed surprised!

Regards

[Rich O Brien]

If your tolerance is +-1mm then you must be designing for NASA!

[slbaumgartner]

As Rich says, the "~" is SketchUp's way of telling you that the actual value can't be displayed fully using the units format you have selected. If the thing you are dimensioning was created by some automated tool such as intersect, this may just be because computer arithmetic isn't exact. But if it is something you drew intending it to be exactly 859.0mm, this means you erred slightly when drawing.

[cotty]

@jamesp said:

I will not worry about it then ...

You should, it might be a hint that some points are slightly off and you might getting trouble with this later on (faces don't appear where you expected them, ...).

[JamesP]

Thank you all for your input on this. I am aware of the problems caused by not being absolutely precise in making sure lines do meet at a point and not just sort of at a point. Hours spent finding where the offending point was.

This raises another query but I will start another thread as it is not related to this.

Thanks again