[OpenSCAD] Difference between modelling with Openscad and Freecad

nop head nop.head at gmail.com
Wed Oct 2 09:29:16 EDT 2019


I never specify the same thing twice. If I need a position twice I usually
make it a module that positions its children and call it multiple times.

On Wed, 2 Oct 2019 at 14:27, A. Craig West <acraigwest at gmail.com> wrote:

> There are two use cases I can think of for being able to query objects for
> information. One is when you import external objects and then wish to add
> things to them. The second is to make implementing generic library code.
> In the first instance, I spend a LOT of time rendering objects with shadow
> cubes in various positions to determine the actual dimensions of the
> imported objects. This work then has to be repeated whenever the original
> object is updated to a new version. Tinkercad appears to be particularly
> bad for putting objects in different positions every time...
> The second instance can be worked around by adding parameters but it is
> essentially redundant information. For example, a module to put a hole
> through a cube could have parameters to specify the size and the
> orientation of the cube, but this is essentially redundant and prone to
> failure. Any time the same data needs to be specified twice, you are making
> updates to the code more difficult to get right.
>
> On Wed, 2 Oct 2019, 09:08 fred via Discuss, <discuss at lists.openscad.org>
> wrote:
>
>> I am of the opinion that if one creates OpenSCAD code in a parametric
>> manner, it is not necessary to query an object. By creating the object in
>> this way, you've "told" OpenSCAD everything that you'd need to know later.
>>
>> cube([10, 20, 5]); definition is fine for many.
>> cube([b_width, b_depth, b_height]); allows for referencing those
>> assignments as often as necessary. If location is important, having
>> parametric values in a translate command provides that information for
>> future use.
>>
>> I learned this method from another OpenSCAD user, many moons ago, and I'm
>> thankful for having been put on the right track. As I assist others in our
>> makerspace, I do my best to pass along what I've learned.
>>
>> On Wednesday, October 2, 2019, 6:35:37 AM EDT, Robin2 <
>> robin at nbleopard.com> wrote:
>>
>>
>> I don't mean the user-interface, which is obviously very different between
>> Openscad and Freecad. Different people like different interfaces but
>> anyone
>> could learn either or both of them if necessary.
>>
>> It seems to me there is a more fundamental difference. With Freecad (and
>> other similar CAD programs) you can define an object and later "ask
>> questions" about that object. For example you can select a point that is
>> the
>> corner of a cube and it will tell you the coordinates in 3D space. And you
>> can locate the surface of a face of the cube even though it may have been
>> rotated or scaled.
>>
>> However with Openscad the process of defining a model is mono-directional.
>> You define the object (such as a cube) and you can have no further
>> interaction with it. You cannot "ask questions".
>>
>> Is this a fair assessment, or am I completely muddled?
>>
>> As I see it very many projects can be created with an Openscad approach -
>> i.e. without ever needing to be able to "ask questions". But I suspect
>> there
>> are some projects where the ability to easily locate a point or a surface
>> of
>> an existing object would be essential. And for those cases Openscad would
>> not be an option.
>>
>> ...R
>>
>>
>>
>> --
>> Sent from: http://forum.openscad.org/
>>
>> _______________________________________________
>> OpenSCAD mailing list
>> Discuss at lists.openscad.org
>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>> _______________________________________________
>> OpenSCAD mailing list
>> Discuss at lists.openscad.org
>> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>>
> _______________________________________________
> OpenSCAD mailing list
> Discuss at lists.openscad.org
> http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.openscad.org/pipermail/discuss_lists.openscad.org/attachments/20191002/b70b236b/attachment.html>


More information about the Discuss mailing list