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Re: 3D-Viewer: limit scale to positive values?

 

I don't know who created the original 3D viewer (our current viewer is a
100%
rewrite by Mario), but VRML was chosen because it could be reasonably
implemented and many users found it helpful for things such as checking for
mechanical collisions on the board and of course also for giving some idea
of what the finished board might look like.  I put in the IDF code and
later the
STEP code because VRML models have no value to me at all for any design
activities that require interactions with MCAD.  STEP/IGES are non-trivial
and
we would probably not have been able to support it at all if not for
OpenCascade.
Remember that even Eagle, which has been around a long time, didn't have
STEP support until shortly before KiCad had STEP support. Out of curiosity,
does anyone have a screenshot from the old 3D Viewer? It would be nice to
show it alongside output from the current one just to show how much better
the new one is.


On Wed, Sep 30, 2020 at 4:02 AM Seth Hillbrand <seth@xxxxxxxxxxxxx> wrote:

> I've never seen another package use VRML.  Everyone uses STEP.  I suspect
> if we were implementing this today, we would look at the tradeoff on
> support/benefit for VRML and limit ourselves to STEP as well.
>
> I like Ian's suggestion for unit options.
>
> -Seth
>
> On Tue, Sep 29, 2020 at 10:22 AM Jon Evans <jon@xxxxxxxxxxxxx> wrote:
>
>> Do other EDA tools allow model scaling?  Altium doesn't even allow VRML
>> import in the first place.
>>
>> On Tue, Sep 29, 2020 at 1:10 PM Seth Hillbrand <seth@xxxxxxxxxxxxx>
>> wrote:
>>
>>> Well, we've backed ourselves into a bit of a corner.  VRML is specified
>>> in meters, so if we're assuming inches, we're a bit off in left field.  But
>>> do we need three separate scale parameters?  We could reduce to 1, correct?
>>>
>>> In the official footprint library, we have 7 footprints that specify
>>> non-unity scaling. (Banana_Jack_[1-3], NS-Tech_Grove_1x04, Fuse_Blade_ATO,
>>> Fuse_Blad_Mini, Oscillator_SMD_TXC0_G158).
>>>
>>> -Seth
>>>
>>>
>>>
>>>
>>> On Tue, Sep 29, 2020 at 9:30 AM Ian McInerney <Ian.S.McInerney@xxxxxxxx>
>>> wrote:
>>>
>>>> We can't remove the scaling option until we make the VRML importer
>>>> handle proper unit selection. I have routinely run into the case where I go
>>>> OpenSCAD -> Wings3D -> KiCad and design a model using mm in OpenSCAD
>>>> because it makes for easier computations (all the datasheet values are
>>>> nicely given in mm) and then have to apply a scaling factor of 0.3937 to
>>>> all the axes in KiCad to make it the proper size because we seem to have a
>>>> hardcoded assumption about what unit system the VRML file is in.
>>>>
>>>> In fact, the KLC says: WRL files do not specify absolute dimensions.
>>>> KiCad normalizes model parameters to units of inches and the internal units
>>>> (dimensionless) of the WRL model must be scaled accordingly.
>>>>
>>>> -Ian
>>>>
>>>> On Tue, Sep 29, 2020 at 4:50 PM Seth Hillbrand <seth@xxxxxxxxxxxxx>
>>>> wrote:
>>>>
>>>>> There has been some discussion to removing the scale option here
>>>>> altogether.  The logic being that if you need the model scaled, you should
>>>>> be doing this in your solid CAD not in your electronic CAD.  I have come
>>>>> around to this idea and it might be worth implementing rather than doing
>>>>> the scale limiting.
>>>>>
>>>>> -Seth
>>>>>
>>>>> On Tue, Sep 29, 2020 at 4:52 AM Mário Luzeiro <mrluzeiro@xxxxx> wrote:
>>>>>
>>>>>> Hi all,
>>>>>>
>>>>>> I'm wondering if it is safe to limit the scale of shapes to be
>>>>>> positive values?
>>>>>>
>>>>>> Applying negative scales will cause inverted shapes and render issues
>>>>>> on the models.
>>>>>>
>>>>>> Could be that anyone in the world is using negative scale values?
>>>>>> or should be safe to limit it?
>>>>>>
>>>>>> This is related with this issues:
>>>>>> https://gitlab.com/kicad/code/kicad/-/issues/5817
>>>>>>
>>>>>> Mario
>>>>>> _______________________________________________
>>>>>> Mailing list: https://launchpad.net/~kicad-developers
>>>>>> Post to     : kicad-developers@xxxxxxxxxxxxxxxxxxx
>>>>>> Unsubscribe : https://launchpad.net/~kicad-developers
>>>>>> More help   : https://help.launchpad.net/ListHelp
>>>>>>
>>>>>
>>>>>
>>>>> --
>>>>> [image: KiCad Services Corporation Logo]
>>>>> Seth Hillbrand
>>>>> *Lead Developer*
>>>>> +1-530-302-5483‬ <+12126039372>
>>>>> Davis, CA
>>>>> www.kipro-pcb.com    info@xxxxxxxxxxxxx
>>>>> _______________________________________________
>>>>> Mailing list: https://launchpad.net/~kicad-developers
>>>>> Post to     : kicad-developers@xxxxxxxxxxxxxxxxxxx
>>>>> Unsubscribe : https://launchpad.net/~kicad-developers
>>>>> More help   : https://help.launchpad.net/ListHelp
>>>>>
>>>>
>>>
>>> --
>>> [image: KiCad Services Corporation Logo]
>>> Seth Hillbrand
>>> *Lead Developer*
>>> +1-530-302-5483‬ <+12126039372>
>>> Davis, CA
>>> www.kipro-pcb.com    info@xxxxxxxxxxxxx
>>> _______________________________________________
>>> Mailing list: https://launchpad.net/~kicad-developers
>>> Post to     : kicad-developers@xxxxxxxxxxxxxxxxxxx
>>> Unsubscribe : https://launchpad.net/~kicad-developers
>>> More help   : https://help.launchpad.net/ListHelp
>>>
>>
>
> --
> [image: KiCad Services Corporation Logo]
> Seth Hillbrand
> *Lead Developer*
> +1-530-302-5483‬ <+12126039372>
> Davis, CA
> www.kipro-pcb.com    info@xxxxxxxxxxxxx
> _______________________________________________
> Mailing list: https://launchpad.net/~kicad-developers
> Post to     : kicad-developers@xxxxxxxxxxxxxxxxxxx
> Unsubscribe : https://launchpad.net/~kicad-developers
> More help   : https://help.launchpad.net/ListHelp
>

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