Hi krass - so yes in a CAD program such a thing that you are describing is called "constraints" - you have to set up the constraints by assigning different types of them to individual features of your model, like you can tell it that a line should remain some certain fixed size, that another line should be tangent to a specific circle, and that there should be a 45 degree angle between 2 lines in another corner of the sketch. Then after those constraints are set up, you edit some piece of the drawing like move an endpoint or change the length on an unconstrained line, and then the rest of the model updates accordingly to enforce the constraints that you specified.

Pilou's examples above show some of that in practice, with other pieces of a sketch getting updated in response to an edit.

But typically in CAD programs functions like that are called "constraints". SolveSpace that I linked to above is one of the easier programs to mess with constraints because it's a very central focus of the program.


> And I'm trying to understand whether it is possible to realize (in principle) any
> improvement to solve this problem.

It is possible, but it will take a very significant amount of time and effort to do it, and the amount of interaction between the constraints and the overall platform makes it difficult for an external script to implement it. At this moment the best way to get that functionality will be to use a different CAD program in combination with MoI.

That type of functionality just has not been a focus area for MoI as of yet.

- Michael

Hello, Michael! Thank you for the detailed answer!
Of course, I realize that it's not so simple - to implement a similar function.
Did any of enthusiasts try to solve this problem - maybe it is interested not only me, who knows? And thank you very much for such a detailed attention to detail. I'm sorry to have taken your time! )

Hi krass, no problem!

re:
> Did any of enthusiasts try to solve this problem

Not as far as I know - it would be difficult to solve with the current scripting system since there is not any way set up currently for a script to receive a notification that an object is being modified. So probably the script would have to do all its own transformations as well...

- Michael

It just is not the biggest problem. IMHO.
There is an excellent program for processing photos - Lightroom.
It does not apply changes to the original file, and to its virtual copy and write next to the original photo format .XMP.

That is, the file does not store the photos in general any data processing, but there are changes in the supplementary file.
Also, when moving to another computer (for example), and the opening of a different version of the program, we get the same changes that originally made us.

But it is, thinking non-programmers, sorry;))

Just to throw a monkeywrench in all of this, I'm thinking he's talking about plain old object hierarchy and instances. With both of these much of what is being discussed could be accomplished and if I'm not mistaken these features are also on the next generation like-to-have list.

Hello,

Companies like Algoryx ( http://www.algoryx.se/ ) provide simulation software, but it isn't cheap. I know Bricsys ( http://www.bricsys.com/) produced Rhinoworks but they no longer sell it, although some of those constraints and dynamics made it into their BricsCAD product.

Hi chipp,

> Just to throw a monkeywrench in all of this, I'm thinking he's talking about
> plain old object hierarchy and instances.

Probably yes for some of the examples, but this particular one here seems to be a constraint based editing mechanism:
http://moi3d.com/forum/index.php?webtag=MOI&msg=7404.6

That's something like constrain one line endpoint to be on a circle, constrain the lengths of the other lines and a couple of locations of other endpoints, then move the unlocked endpoint around and have it recalculate.

I think that's the particular image that made me realize that constraints are what's being asked for.

- Michael