Hi Jeff, well after browsing through that thread a bit I can see that you're very familiar that offsetting a polyline is not the same thing as offsetting an arc! ;)

It is surprising that there is so much disagreement over there about this - I mean if you just draw a snapped "half circle" arc in Sketchup and then offset it, the offset result is not a half circle anymore... But it's because you didn't really have a half circle in the first place, you really just had a polyline in the general shape of a half circle.

That's all a consequence of having all geometry made up of little line segments and facets. If you're trying to do stuff involving curved shapes sketchup becomes problematic in a lot of ways for those kinds of tasks, particularly if you're trying to do "curved shapes with accuracy"...

- Michael

Hi Jeff, so I learned from browsing that thread a bit more that there is actually the concept of an arc object in SketchUp, and that certain operations like entity info or dimensioning are able to get at that original arc center and radius information. That's kind of strange that they did not make offset make use of it as well though.

That's pretty confusing to have only some tools recognizing the arc information and others just using the polyline approximation.

- Michael

i've always found the behavior strange but in the past, i sort of just worked around it because i thought that's 'how it is'.. (and it wasn't really until that thread started that i realized it wasn't one of those things that everyone just automatically realized..(of course everyone knows it's segments.. but i now don't think too many people realize the errors created when they think they're doing an offset on something which sketchup is calling an arc) anyway..

thing is, i'm on mac.. we didn't realistically start getting nurbs until the past few years.. i started sketchup around 8-9 years ago so i had lots of time with the app and figured out ways to get accurate arc info out of sketchup.. even with them being segmented like that.. it's just that it's an often convoluted process to get things/vertices in their proper position..
then i started using nurbs apps and messing around with arcs is child's play.. i tried some things in rhino when i first started using it which were difficult to do in sketchup and i felt like the app laughed at me as if saying "are you serious? is that all you have?! :) )

so now, when i want to do something basic in sketchup and i can't, i guess i get frustrated with it.. (and i'm talking real basic.. there's no compass in sketchup. but you do see hints of one in certain behaviors such as the ability to draw an arc tangent to a line via a tangent snap).. but if the devs don't want to smarten it up, that's totally fine.. and as far as i can tell, it's not going to change in this area so...

anyway.. @the_offset

after thinking about it some more, i actually use the round corners in most situations.. your latest example finally made something click in me to where i think "oh. right.. i know how i would want that to be handled.."

it would be this way:












you'll see a very similar situation in the top-right of this:












out of curiosity (i.e.- sketchup's offset & follow me tools work exactly the same), i tried sweeping it..

moi gives:






rhino spits this out :)




(and i realize i shouldn't be trying to draw it like this anyway.. just curious though)


------
but yeah, i never actually realized before that there isn't one way to offset (i mean, i think there's only one way to offset individual curves.. it's these various intersections that are open to interpretation.. and i don't think there are solid enough grounds for anyone to claim "no.. this is the right way"


(well, i guess you've already said that stuff.. i'm just repeating to myself so it will stick ;)



(**ps_ i'm on the beta right now.. it's nice man.. the navigation/inferencing is tops.. i might be hooked this time around :)

Hi Jeff, that's cool that you're back messing with the beta, I hope it can stick! :)

And yeah that particular stuff that you're building is very not like traditional semi-box-like architetural forms like sketchup is really designed to work with - a NURBS modeler is a way better fit for that kind of geometry. Pretty much a 100% perfect fit really with the kind of broadly curved profile-driven geometry that you have there. There's so many tools that will directly apply to that kind of construction - sweep, blend, offset, ... - and for construction it should also be a really big advantage to have a sort of ideal master model that can then be cut up in different ways as you need.

When you try to do that with a bunch of lines and facets you're kind of fixing a sort of cut up pattern directly in the base design instead of being able to create an idealized reference design...

Your shapes there just do not fundamentally resemble a box or a prism type shape, which is what sketchup is totally oriented around producing.

- Michael

(i meant to say trial version.. but i think you know what i was saying ;) )

and i'm assuming the trial is the official release now? i mean, i can save etc so the only limitation is time, right?

I believe yes for the trial 30 days :)
But Michael will precise if there are the same functions than on PC...and than inside the Beta V3

Hi Jeff, yup the trial version is fully functional for the 30 day period, it's not limited in any way other than that.

The trial version is for version 2.52 , there is also a v3 beta release that has some various new things in it which is in beta release currently - that one is only available to customers though.

- Michael