Sketching (furniture) with rectangles

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NormandC
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Re: Sketching (furniture) with rectangles

Postby NormandC » Mon Mar 07, 2016 12:13 am

I'm sorry guys, but what you're suggesting is still quite involved. Sometimes we have to sit back and consider simpler solutions.

This was done using two part cubes and two Draft Arrays. It can't get any simpler, and it's FAST. No sketching whatsoever.
FC_furniture_shelf_example_01.png
FC_furniture_shelf_example_01.png (37.6 KiB) Viewed 891 times
I'll also remind you guys that Expressions can be used to create formulas controlling dimensions of even primitives. This could be used in conjunction with the Spreadsheet Workbench.

But in my opinion people go to too much trouble attempting to build a fully parametric and automatically resizeable model. Sometimes it just bring unnecessary overhead. In the example above, granted, if I decide to change the size of the panels, I will have to change the array values and the placement of the parts. So what? I'd wager it will actually be a lot less time-consuming than trying to produce a complex model that can be automatically updated by changing a few dimensions in a spreadsheet. Or one that requires editing quite many sketches.
bejant wrote:Edit: You guys are posting so fast I can't keep up!
:D
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furniture_shelf_example_normandc1.fcstd
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Last edited by NormandC on Mon Mar 07, 2016 12:35 am, edited 1 time in total.
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NormandC
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Re: Sketching (furniture) with rectangles

Postby NormandC » Mon Mar 07, 2016 12:26 am

ivo wrote:Edit: so it's an accident, personally I still find it illogical that it doesn't work.
But it is logical, as I wrote just after your post:
NormandC wrote:That is not what the PartDesign Pad is intended for. Its intent is to produce a single solid. Even using the Part Extrude won't give you the result you're looking for: under the hood, the software first need to create a planar face out of the sketch elements, then extrude the face. It cannot get a valid face with a profile containing crossing elements.
Blue text added to make it clearer.
ivo wrote:Especially since Fusion doesn't even give me a funny look for sketching it, as I assumed would happen here.
I'm not sure how Fusion comes into this, if you could elaborate.

But anyway, with all our posts I think you have a lot to think about.

Seriously though, it would really be useful to reply to my questions from here.
ivo
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Re: Sketching (furniture) with rectangles

Postby ivo » Mon Mar 07, 2016 1:38 pm

Wow, that's a lot of answers to consider indeed.
The main goal is fast protoyping, I don't need to include exact assembly specs and components but I would need to be able to change dimensions easily and make a quick render of the thing.
I totally get that if I started out with one big rectangle and started subtracting from that (via other rects) and adjusted the constraints to match the approach then I could get the correct end shape and pad should work without issue. I was hoping I wouldn't have to do that though so I could retain at least some semblance of realism. It would appear though that it's kind of difficult to achieve. Maybe there should be a generic sketch mode that doesn't try to merge everything into one solid. (Extruding kind of works only I'd have to manually generate faces for all the "panel" rects.)
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DeepSOIC
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Re: Sketching (furniture) with rectangles

Postby DeepSOIC » Mon Mar 07, 2016 2:13 pm

Another option may lie in Arch workbench, somewhere around wall feature... But Arch is completely out of my scope of competence so far.
EDIT: yeah, definitely worth a look at:
arch wall.png
arch wall.png (59.85 KiB) Viewed 855 times
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NormandC
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Re: Sketching (furniture) with rectangles

Postby NormandC » Mon Mar 07, 2016 8:02 pm

Ivo, I don't understand your fixation (may be too strong a word) on working with sketches. Your desired end result is a 3D model, is it not? I remain convinced my method would be faster and easier to manage. Let me explore the use of Expressions and Spreadsheet to make it more automated, I'll get back with an updated file.

Would you have a 2d diagram of a typical layout as an example, or is the one posted in the first post the most complete one you'll have?

Edit: I've been sidetracked tonight, I didn't have time to make complete tests, but it is indeed possible to create a formula for the array interval using the property of another object (say, the width of a shelf). Everything could be driven from a spreadsheet, even the number of instances in the array.
jmaustpc
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Re: Sketching (furniture) with rectangles

Postby jmaustpc » Tue Mar 08, 2016 4:49 pm

NormandC wrote: Edit: I've been sidetracked tonight, I didn't have time to make complete tests, but it is indeed possible to create a formula for the array interval using the property of another object (say, the width of a shelf). Everything could be driven from a spreadsheet, even the number of instances in the array.
Yeah, expression and spreadsheet are terrific ! :)
ivo
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Re: Sketching (furniture) with rectangles

Postby ivo » Tue Mar 08, 2016 8:48 pm

NormandC wrote:Ivo, I don't understand your fixation (may be too strong a word) on working with sketches. Your desired end result is a 3D model, is it not? I remain convinced my method would be faster and easier to manage. Let me explore the use of Expressions and Spreadsheet to make it more automated, I'll get back with an updated file.

Would you have a 2d diagram of a typical layout as an example, or is the one posted in the first post the most complete one you'll have?

Edit: I've been sidetracked tonight, I didn't have time to make complete tests, but it is indeed possible to create a formula for the array interval using the property of another object (say, the width of a shelf). Everything could be driven from a spreadsheet, even the number of instances in the array.
Well you have to understand that this is a low priority side project and the intention was to use a pre-existing solution that lets me "draw" once and modify with ease. So delving into the underbelly of FreeCAD wasn't really my intention (I'm new to it anyway - haven't modeled anything in more than a decade). Sketches with constraints would also let me easily just make a screenshot and I'd have a basic blueprint available to pass on for refining. I'm looking into designs with a little more complexity (tv stand, bathroom cabinet set). No doubt you could easily solve the problem with an algorithm and a sufficiently detailed data set but that's a little out of my time allocation. Guess I'll just do it with solids in the first place as long as those also take constraints in the same manner.
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NormandC
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Re: Sketching (furniture) with rectangles

Postby NormandC » Wed Mar 09, 2016 3:15 am

I understand. A work colleague (who's a CAD enthusiast as well) with whom I discussed this "problem" at lunch had this very simple idea that I didn't think of (a "doh!" moment for me): just create multiple rectangles in a single sketch like you want to, but make sure they do not connect or intersect. You could add a very minute distance between them, like 0.01mm. That would create a sketch containing "separate islands" which is not supported by PartDesign for a base feature (because it would create multiple bodies), but you could use Image Part Extrude instead since it has no such limitation (remember to check "create solid" otherwise you'll get shells).

In the attached file, only 2 dimensional constraints need to be edited to change the height and width of this "cabinet".
FC_furniture_shelf_example_03.png
FC_furniture_shelf_example_03.png (58.42 KiB) Viewed 784 times
ivo wrote:would also let me easily just make a screenshot and I'd have a basic blueprint available to pass on for refining
Just FYI creating a view on a drawing page would not take that long, and with the Drawing dimensioning add-on dimensions could be added quickly, one of us regulars will be happy to walk you through it when you need.
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furniture_shelf_example_normandc3.fcstd
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Last edited by NormandC on Wed Mar 09, 2016 5:56 am, edited 1 time in total.
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NormandC
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Re: Sketching (furniture) with rectangles

Postby NormandC » Wed Mar 09, 2016 5:55 am

It's me again :D
NormandC wrote:it is indeed possible to create a formula for the array interval using the property of another object (say, the width of a shelf). Everything could be driven from a spreadsheet, even the number of instances in the array.
Even though it's probably not the way you'll go, I had to test this for myself.

And I can only come to one conclusion, one Jim arrived first:
jmaustpc wrote:Yeah, expression and spreadsheet are terrific ! :)
This is pretty awesome. :)

In the attached file, everything is controlled by the Spreadsheet cells in yellow. As shown in the screen capture, it is best to open the Spreadsheet tab (double-click on its label in the Model tree) then set the windows to mosaic display, so you can see changes without having to switch tabs.
FC_furniture_shelf_example_normandc2a_01.png
FC_furniture_shelf_example_normandc2a_01.png (88.69 KiB) Viewed 781 times
Reminder: this requires a recent development release (0.16.65xx) of FreeCAD.
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furniture_shelf_example_normandc2a.fcstd
(20.66 KiB) Downloaded 37 times