Hi Eric,

It's probably not going to work to try and get that exact same result - some complications are that sweep is only going to try to do miter joints and not stuff like this:




And also all your pieces here are not just rectangles like for instance here you've got like a trapezoid with a slanted top:



So that kind of stuff probably won't be particularly feasible for sweep to do all by itself.

However, I think that I can tune up how the mitering is done when you have the Twist = Flat option enabled, right now it is not working well with that combination but I think it will be possible to fix that up so that you would get a similar kind of result quickly like I think you were hoping.

- Michael

Hi Eric, actually after looking at it I don't think that twist=flat is going to help you for this case, since it produces stuff like this:




After looking into it a bit more yet, I don't think that sweep will be able to do this for you - when you have one profile that you are trying to sweep, sweep does not do anything to change the shape of the profile.

I think that's what you would need to have happen for your case to work right, the rectangle would need to mutate to a trapezoid or parallelogram for different segments, but sweep does not know how to do that.

Like for example in your model here you have a rectangle that is sweeping downwards:



But the adjacent piece next to it here:



Is not actually a rectangle in that same kind of cross-section, it is a trapezoid with a slanted top:




Sweep does not know how to swap out rectangles for trapezoids in different areas, it only tries to put a rectangle (or whatever your profile shape was) on everything.

So I don't think sweep is going to do that for you.

- Michael

Hi eric, so for your fascia I don't think sweep is going to be able to do it for the reasons mentioned above.

But here are some alternate steps that still work on things in a kind of larger batch and so are likely to be much faster than going around piece-by-piece.

To start with, I made a flattened plan version of the path, like this:



The easiest way to do that is to go to a side view, and grab a corner grip of the edit frame:



And just drag it downwards until you get the "flat" snap. Hold down Ctrl if you want to make a copy of the object (which I did in this case):



Then I used Edit/Separate to break up the original path, and kept only these 2 full profile pieces from the one end, which I extended slightly:



Then use Offset with the "Cap ends" option to thicken that into a closed curve like this:



Also use Offset on the flattened plan outline:



So now you've got 2 thickened curves that look like this:




Believe it or not, this is all ready to produce a result!

Just select the side piece:



Now run Construct > Boolean > Intersection, when it prompts you to Select second object set, select the 2 plan curves and push Done or right-click and pow! here you go:




I've attached an example model as eric_fascia_example.3dm if you want to check it out.

This works because MoI's booleans are able to work with planar curves and give the same result as if the pieces were extruded into solids. You could also extrude each piece and then do boolean intersection between the extrusions, but that is not necessary since the booleans can handle the same thing automatically.

Does that possibly give you a quick way to get an acceptable result rather than going through segment-by-segment constructing things?

It is still not completely identical to your original (where you had some different structures around some joint areas) but it seems like it is the right overall shape that you are probably looking for?


(also note that I just offset by some arbitrary distance, I did not use the proper distance there to exactly match your model)


- Michael

I think I just popped something in my left ventricle....That is wierd stuff!

@ Bur
Take this in your pocket :D

The boolean isec recovery machine? :o

Hi Burr, but will it save you from this one? :)









- Michael

Must..... get..... air.......

Cant.....take....much.....more.......

must....hold...on!

Oh Snap !!!!







Sorry about that Burr! :) Time to hit the sack...

- Michael

I fell over, hit my head and saw Rod Serling! He told me to go to bed too.

Seems there are some glitch ;)

Hi Pilou, yes I still have some work to do for the mitering, especially on curved segments (see this previous post: http://moi3d.com/forum/index.php?webtag=MOI&msg=3170.40)

But one other thing to keep in mind is that often times fonts are made up of poor quality geometry, which you cannot see very easily when it is only being drawn as 2D ink, but which become much worse when used for analytic purposes such as intersections, etc...

For example if you use Edit/Separate on your path curve, you will see that it is made up of a whole bunch of fragmentary little pieces like this:



That's not good to have such a messy and chaotic base structure.


If you try the attached version (Mister2.3dm) where I used the Rebuild command on your curves to do some cleanup on them, you should see a much better result already.

I am going to be working on improving the intersection mechanism, but even after that is done it is still going to be fairly sensitive to having poor quality input curves, you will likely still need to prepare better quality input paths for it to be able to do a good job even in the final release version.

Text shapes coming directly from fonts in general are difficult - a combination of many sharp corners and tight areas as well as poor quality geometry tend to make it not a very reliable area for more complex calculations, especially things that involve extensions and then intersections of extensions, such as filleting or also this mitering mechanism falls into a similar category as that.

- Michael

Hi Michael,

> Oh Snap !!!!

Makes sense, but who knew! MoI is for fun too!

Thanks :)

Couldn't help myself.

What a hoot, Michael!

Leonard

Wow Michael,

Thanks for your very thorough explanation ... and the result.

When I have had a chance to go through you solution I think it will work well for me.

I didn't really expect MoI to cut the trapezoidal slope on the horizontal segments but thought maybe I could plane them off afterward if the result was a rectangular section throughout.

I could not have thought to try your boolean solution ... brilliant!!

cheers,
eric

Hi eric,

> I didn't really expect MoI to cut the trapezoidal slope on the horizontal
> segments but thought maybe I could plane them off afterward if the
> result was a rectangular section throughout.

Yeah but sweep doesn't really understand that you want to alter the shape later - the miter corner thing is expecting to have things match up right at the sweep time...

There is a way you could get something like that to work though - if you use Edit/Separate on your path so that each line segment gets treated as an individual sweep path rather than as a connected path.

That will then produce something exactly like a set of simple boards for each line segment, without doing any corner mitering. But then you're going to need to handle extending and doing some of those additional cuts more manually.

The boolean method basically incorporates the planing for everything all in one shot. But also it kind of makes the result more as one combined piece (with the proper shape you are looking for I think though), not necessarily like a set of individual board pieces like a sweep type method would produce.

- Michael

Hi Michael ...

It would be rare when I would actually need the fascia to be individual ... I think the boolean solution will work well in most cases. It is mostly the need to do it quickly and have it as an entity for rendering purposes.

Thanks for your effort on this.

The new sweep works great on window and door frames and I am sure lots of other things I'll be doing.

cheers,
eric

< I used the Rebuild command
Sorry where is it? It's a short cut?

@ Anis: Cool but you miss one level axis! ;)

A super stormbrain book about auto reference and other crazzy things!

Hi Pilou,

> Sorry where is it? It's a short cut?

I have not figured out a place to put it in the UI yet, so to call it you have to set up a keyboard shortcut for it.

- Michael