trimming a spring

 From:  Michael Gibson
4215.9 In reply to 4215.8 
Hi Danny,

> as for a too tight of a tolerance no so much of a
> problem, within NX anyway.

The same issue of excessively dense fitted data will be happening in NX as well with a too tight tolerance, but since NX is run on beefy workstation computers that helps to mask the problem.

What are the hardware requirements for NX anyway - what would they say if you told them you wanted to run it on a $300 little netbook computer, probably just laugh?


> 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.

Just in general operations that involve a fitting tolerance don't go along well with such a divergent combination of scales, if you need to create objects like that you're probably better off having them be different parts instead of trying to create one single solid part object that has such a variance in it.

But the way that such things can work ok with a relative tolerance is when it is taken from the smallest piece that is being used for a particular operation.

So for example if you Boolean the 10,000 unit object with the 5 unit one, the relative tolerance is calculated for each of those separately, and then the smaller one is the one actually used for the boolean operation. That's actually how the booleans work currently in MoI.

The relative tolerance system still needs to be tuned up in some various ways though, some commands don't use it yet and some commands may be using the size of the bounding box around all the involved objects instead of only the smallest one, and also I think I need to tighten it up further for smaller sized objects.


> but why wouldn't you have a a user settable tolerance buried
> somewhere for the advanced user who would understand how
> it works

There are various problems with that - if a setting like that was carried around inside of a file you end up with things like non-advanced user opening up a file that was created by an advanced user and then trying to model something new in the file and getting really confused why things are either sagging a lot or taking a long time to finish because they don't understand that the advanced user set some special setting in the file.

So such settings have a way of kind of "leaking out" and affecting other people.


> 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?

Just in general I hate that kind of workflow where you have to make choices or jump through hoops before you can even start drawing things.

It's a big focus for MoI to try and reduce such overhead and just let you draw more freely...

- Michael