Hi Michael,

I've got a feeling we've discussed this before, have we? Anyhow.....

> Having it user settable is not so great because
> in my experience I have seen it frequently get
> set to poor values, like 10000 times more precise
> than is actually needed, causing a really really big
> increase in file size and calculation time.

> There's also the reverse problem of it getting set too loose as well.

Agreed, I've seen this misused also, there have been many times where we had to rebuild models because of a too loose tolerance, as for a too tight of a tolerance no so much of a problem, within NX anyway.

> Also just the general strategy of having it set
> to any one single specific value makes for difficulties
> in several kinds of uses like when someone creates
> an object that has a large scale, say like 10,000
> units across. With objects at that kind of scale trying
> to target a fixed tolerance of something like 0.001 or 0.0001
> units is not good since it is so very tiny in comparison to the object.

I understand that, but what I don't understand is, if I have an object 10,000 units across and then have smaller details between 5-10 units in size within the same file I would like to believe that there would be no bad side effects because of this way of working.

> So that's why I want to move more towards a
> kind of relative tolerance that tries to operate at
> some fraction of the object's overall scale, the
> idea for that is to make operations automatically
> adapt their accuracy to large or small objects instead
> of requiring every user to be an expert at judging
> fitting tolerance values before they start working on every project...

I like the automatic adaptive tolerance system that you've implemented and still working on in other areas, but why wouldn't you have a a user settable tolerance buried somewhere for the advanced user who would understand how it works or maybe have environment presets where the tolerance is set depending on what the user is planning to model, Large models, medium models, small, tiny and general, something like that?

> The main goal for MoI is to generally target
> an accuracy of 0.001 units for objects built at a regular scale.

How do we define a 'regular' scale, a regular scale to an architect would be different to that of a Jewellery designer, that's the reason I believe there should be some tolerance choices available to the user.

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