Sketcher tutorial

[chrisb]

Please continue soon with the constraints.

Thanks for the kind words, that always motivates. The constraints part currently seems to be even more challenging, it might take a week or two.

[NormandC]

Hi Chris,

Massive work!

It'll take me time to go over it, but at first glance, it looks great.

[chrisb]

Hi Chris,

Massive work!

It'll take me time to go over it, but at first glance, it looks great.

Take your time, I'll wait for your comments.

[chrisb]

As a counterexample I need a sketch showing the "unsolved" solver message. I have seen it numerous times but now I am unable to reproduce it.

[NormandC]

Maybe try with too many symmetric constraints?

[chrisb]

Thanks for the hint: Symmetry implying a horizontal constraint plus setting a vertical one; OMG!

[chrisb]

I have updated the file in the first post. If you have read it before: almost nothing has chhanged in the first two parts. I have added the section 16 about the solver.

[ppemawm]

First off, thanks for taking the time and effort to generate this needed document. It is especially difficult for an expert like yourself to write a beginner's guide because what an experienced user does automatically can be total confusion to a beginner.
Well done! I look forward to you finishing a great start. Getting started in my experience is the most difficult part of the process.

A couple of minor comments:
p.2. "I usually leave all the checkboxes unchecked" Me too, but a beginner would probably like to know what their purpose is. I have no clue.
p.4. "...creation mode" Might mention that creation mode is set in Edit>Preferences>Sketcher>General.
p.5. typo "mosuse"
p.6. "Select the center..." A better English word would be 'origin'. I first took center as the midpoint of the line so could not reproduce your example.
p.11 see comment on p.4 above.
p.31 typo ..."ketcher panel again."
p.32 "...making the sketcher so precious." Unambiguous might be a better word or clear, precise, etc.
p.32 typo "whith"
p.32 "...recalculates the whole sketch." Maybe add 'to determine if there is a unique solution...'
p.34 typo "on" ,bottom of page, should be 'one'.
p.35 typo "whatch" middle of page

Highlighted copy is attached.

sketcher_markup.pdf

(580.3 KiB) Downloaded 325 times

Other brief comments to your other questions IMHO:

- is it too detailed? Not at all
- I put the Point as geometric element to the end because it is rather construction geometry. Should it be the first among the geometric elements? Best to keep it separate from actual geometry.
- should I add B-splines, ellipse and other conic sections? Yes, for completeness.
- when being in Sketcher, do we talk about "3D view"? I ask because it is rather 2D. Good point, when I first started I thought the sketcher should do 3D.
- the examples and exercises are not final yet, I am looking for easy to grasp models, preferably with some well known application; any proposals? Something from one of the recommended tutorials.
- I am not sure about the position of the external references section. Should I put it into the constraints section? Yes

[Isabel]

Hi Chris, thank you again for the new section about constraints. Even if I can handle things correctly, I prefer to understand why.

Can you tell me, why there are two different messages for the same thing? The "Unsolved" example seems to be just "Overconstrained". Similar with the "Redundant" case and the example with the additional equality constraints. The latter seems to be nothing else than redundant.
Thanks for any clarifying words
Isabel

[chrisb]

Thank you for the detailed comments!

A couple of minor comments:
p.2. "I usually leave all the checkboxes unchecked" Me too, but a beginner would probably like to know what their purpose is. I have no clue.

I have no clue either. I will dig into this some time in the future, when looking into attachments. I probably should delete the word "usually".

p.32 "...making the sketcher so precious." Unambiguous might be a better word or clear, precise, etc.

I rephrased this as it seems I was unable to transmit what I wanted to say.

p.32 "...recalculates the whole sketch." Maybe add 'to determine if there is a unique solution...'

took your proposal without "unique". I will talk about this uniqueness somewhere else

- the examples and exercises are not final yet, I am looking for easy to grasp models, preferably with some well known application; any proposals? Something from one of the recommended tutorials.

Good idea. The Glouglou model covers much of which I need here.

All other points are taken gratefully and are mostly already implemented.