new link to download the install file:
https://we.tl/t-Q1SG9WKeMA

a video:
https://www.youtube.com/watch?v=55R4VuHLKo4

length snapping does not get a lot of interest, but i add information on how i solved my problem, in case of somebody might find it useful in the future...

in my case length snapping was not the solution

The cursor movement is not changed; instead, a message is shown based upon the movement of the mouse, so the user can decide when it is time to stop moving the mouse and click the second point
https://vimeo.com/939627532?share=copy

this is low level programming, but it works.

new link to download the install file:
https://we.tl/t-Q1SG9WKeMA

a video:
https://www.youtube.com/watch?v=55R4VuHLKo4

Here is the install file of FTO, an extension to model facade scaffoldings using Futuro components
https://we.tl/t-77pGglDnwJ

it is a demo version limited to facade scaffoldings; the subscription version includes birdcage, circular, access...

I know there is a debate about the usefullness of length snapping in sketchup.
But it has been used efficiently by scaffplan:
https://www.youtube.com/watch?v=B5MPRqQPV3U

at about 1:50

From what i red, there is no way to customise sketchup length snapping though ruby, except changing the step.

Is there a way to do it?
for example make the cursor jump to 0.3 / 0.5 / 0.7 / 1.0 / 1.5 / 2.0... m, which are usual length of scaffolding components?

thank you for taking the time to try, and for the advice

to try the demo version of PLY shown in the video, download the instal file from this link
https://we.tl/t-s5Q4Lby9iJ

if you do so, you will be able to watch another video that shows the full version of PLY.

Full version has functions to get a bill of materials, modify structures by adding components, exporting to PDF, ...

it is a development i made many years ago, but i could not find anybody in France interested in it, so i stopped

If it draws interest among english speaking sketchup users, i could make an english version of the full version of PLY

i uploaded a video to show how it woks

https://www.youtube.com/watch?v=hfOW4vPkXAQ

I uploaded the instal file here:
https://we.tl/t-s5Q4Lby9iJ

this kind of structure is often used to support ligths

the plugin makes a structure with 2 3 or 4 standards, possible dimensions range from 2 to 10 m

It is a demo version but functional

https://skpply.blogspot.com/

@rv1974 said:

@glro said:

@rv1974 said:

Judging by your analysis we will never see anydecent\useful SU plugin again. Let's hope you're not 100% right.

there is another conclusion in form of a question: how do you find money to developp very specific extensions that will only interest a few users ...?

sometimes, passion and generosity come to an end

many of the programmers who were posting here 10 years ago, are not there anymore.
There must be a reason, and my guess is that it is an economic reason.

If you really need a specific development, you could try https://www.freelancer.com/
maybe try to find others with the same need and share the cost

... just ideas

Nobody argues with your truisms, no illusions here. Your points (based on yourperception of the world) are legit in in 99% of cases.
However there still tons of free\donate$5-10 scripts on forums all around the Web which leave a tiny chance for requests like this one.
BTW Selling at least 100 copies of $5 script globally (with millions of SU\Acad users) rather justifies 1 week(?) of skilled scripter ourside 'golden milliard'. Check the salaries in Vietnam\Ukraine\India etc).

@chon: Once you (architect\ArchVizer) try it you can't live without it. One of the most popular scripts on Scriptspot (made in Germany, sold for $5

500 $ a week might be a lot in Vietnam, maybe not so much in Germany

anyway, i don't want to argue or upset anybody here in the forum; i just wanted to mention the economical side of developping an extension for sketchup

@rv1974 said:

Judging by your analysis we will never see anydecent\useful SU plugin again. Let's hope you're not 100% right.

there is another conclusion in form of a question: how do you find money to developp very specific extensions that will only interest a few users ...?

sometimes, passion and generosity come to an end

many of the programmers who were posting here 10 years ago, are not there anymore.
There must be a reason, and my guess is that it is an economic reason.

If you really need a specific development, you could try https://www.freelancer.com/
maybe try to find others with the same need and share the cost

... just ideas