kicad-developers team mailing list archive

[Jon Evans <jon@xxxxxxxxxxxxx>]

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
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>>>
>>>
>>> --
>>> [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
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>>>
>>
>
> --
> [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
>