kicad-developers team mailing list archive

[Seth Hillbrand <seth@xxxxxxxxxxxxx>]

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
>>>>> _______________________________________________
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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
>>>>
>>>
>>
>> --
>> [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