A randomly started discussion about the necessity of the PD single solid rule

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adrianinsaval
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by adrianinsaval »

C_h_o_p_i_n wrote: Thu Mar 23, 2023 8:06 pm That sounds a lot like some religions state ... you shall not x you shall not y ... only the z is the true pure way to go.
No one will force you to change your way, if you're eager to follow your own single solid per body paradigm.

But all other will have the freedom to do it different if they like to.
+1
FREECAD should not be limiting stuff for the sake of limiting.
Last edited by adrianinsaval on Thu Mar 23, 2023 11:11 pm, edited 1 time in total.
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by freedman »

FREECAD should be limiting stuff for the sake of limiting.
I see what you mean. If it can be done then it should be allowed.

I guess it would make a Sketch based assembly, the sketch would determine the unified Placement and location of the objects. There have been times when I wanted to use a sketch to cut thru multiple objects.

When I was new to CAD I would use that, but I have learned thru experience that it's better to make them separate objects because as soon as I use that concept someone comes in and says "Can you move this over, up and turn just a hair". What could be a quick properties change could instead turn into a full blown Sketch change. No thanks.

But, yes, it should be allowed. I/you have changed my mind. Make it free to use.....
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by C_h_o_p_i_n »

freedman wrote: Thu Mar 23, 2023 8:41 pm
No one will force you to change your way, if you're eager to follow your own single solid per body paradigm.
Good point. If we have a switch to set either then I would be all in.

I always thought there was a structure to modeling where you can't have free hanging objects. I thought every object (has a placement) and must be connected to something, if you want to have a free hanging object then you need an Assembler to be used to control it's placement.
Well ... is [0.0;0.0;0.0] realy THE ( one & only ) origin ... ?
Its going to be a kind of philosophical question.
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-alex-
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by -alex- »

adrianinsaval wrote: Thu Mar 23, 2023 9:00 pm
C_h_o_p_i_n wrote: Thu Mar 23, 2023 8:06 pm That sounds a lot like some religions state ... you shall not x you shall not y ... only the z is the true pure way to go.
No one will force you to change your way, if you're eager to follow your own single solid per body paradigm.

But all other will have the freedom to do it different if they like to.
+1
FREECAD should not be limiting stuff for the sake of limiting.
+1
Multi-solids should be authorized in PD as an option, as said above. Let users decide the workflow.

A last exemple why single solid paradigm can be so tedious: for welded parts! Welded parts are made of multiples solids, each solid is quite simple.
ATM in PD, you have to create multiples bodies, each on for such simple plate, or gusset, or round bar,.... then use binders to make all of this parametrically... that's crasy.
Hence I design welded parts with Part WB, that's much more straight forward, but use PD WB with multi-solids enabled would be more convenient.
In PD WB with multi-solids paradigm, body container will be to consider as a Part container for PD context.
That's what it is in RT branch.
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by wsteffe »

onekk wrote: Part Design Wb is not following a modelling paradigm.

That from what I know are two:

- CSG Constructive Solid Geometry
- BREP Boundary Representation
BREP is not a modelling paradigm. It is a data structure used in the OCC kernel (and in most other CAD kernels) to represent geometrical objects.
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by wsteffe »

wandererfan wrote: It may be that PD operations are smarter now and can all handle multiple solids as input. Somebody familiar with the internals of PD would have to answer that question.

This was an interesting question. The fact that it is still unreplied lets me think that FC commutiny misses a maintainer of PD WB.
If that is true it is a very bad situation (I.M.O.) considering that PD and Sketch are, by far, the most used WBs.
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by drmacro »

wsteffe wrote: Fri Mar 24, 2023 8:44 am
wandererfan wrote: It may be that PD operations are smarter now and can all handle multiple solids as input. Somebody familiar with the internals of PD would have to answer that question.

This was an interesting question. The fact that it is still unreplied lets me think that FC commutiny misses a maintainer of PD WB.
If that is true it is a very bad situation (I.M.O.) considering that PD and Sketch are, by far, the most used WBs.
IMO, it is also a bad situation that so many people restrict their creativity by attempting to ignore everything but PD and Sketcher. :(
Star Trek II: The Wrath of Khan: Spock: "...His pattern indicates two-dimensional thinking."
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wandererfan
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by wandererfan »

All this talk about a "single solid rule" is misleading. It isn't a rule. It is a reflection in the implementation of a design decision made early in the development of PDN.

Nobody sat down and said "let's make an arbitrary rule to restrict people".
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Re: A randomly started discussion about the necessity of the PD single solid rule

Post by wandererfan »

-alex- wrote: Fri Mar 24, 2023 8:06 am ATM in PD, you have to create multiples bodies, each on for such simple plate, or gusset, or round bar,.... then use binders to make all of this parametrically... that's crasy.
This speaks more to shortcomings in FC's assembly functionality more than PD. Each plate/gusset/bar is a single solid in real life, and we align and attach them into a built up component.

Shapebinders are a work around.
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