[Plugin][$] Curviloft 2.0a - 31 Mar 24 (Loft & Skinning)

jgb · 11 Jan 2014, 18:34

CL will fail on any one of the following most common conditions... (as well as a few others)

2 lines not joined at "endpoints" although they look like they do. Endpoints joined when "Constrained by" will not loft.
a tiny fragment at an endpoint is taken as part of the perimeter CL finds, or you define by selection.

When CL defines its perimeter, use the colours as a guide to where problems may lurk. Fredo has stated that the colours are not meaningful by design, but I have noticed that if the perimeter segment is a complete yellow it has no problems, but that is NOT a given. It can be almost any other colour, and it could still have a problem, usually at the very ends. However I have found that red indicates a problem that could be at either endpoint, or anywhere on the curve.

If a perimeter is made up from several colours, then there may be a problem at the endpoints where the colour changes.

The common fix is to zoom in on the endpoint CL has indicated to perhaps be a problem, and fix it.

Another way is to widely left-to-right select one line segment that includes the 2 endpoints and delete it. That will get rid of any gaps or fragments. Then redraw endpoint to endpoint. Make sure you do not join the lines on an endpoint that is "constrained by" or that is on a point outside the current context.

On a large complex loft you may want to put temporary lines in to breakup the large curve into several smaller ones, and CL each of them. The one that will not loft contains the problem. All this does is narrow down where to look. Delete all the temp lofts when done.

On a long complex curve as you posted, I would split it in a binary fashion. CL one 1/2. If it lofts, split the other half in 2 and repeat. If it fails, split that in 1/2 and repeat. Do this until you get down to a manageable few lines to look at in detail. This does not preclude multiple problems, but it does find clean sections as well as the problem ones.

And finally, when CL does not loft a seemingly clean perimeter that is attached to other geometry in the model, do this;
Select all of the perimeter lines manually and move/copy them to some free space along an axis line. You could also make the perimeter a group and edit the group.
Inspect and fix the perimeter for gaps and fragments.
CL should then loft.
Simply move the grouped loft along the axis back to its original position.

jeff hammond · 11 Jan 2014, 18:47

@jgb said:

CL will fail on any one of the following most common conditions... (as well as a few others)

2 lines not joined at "endpoints" although they look like they do. Endpoints joined when "Constrained by" will not loft.

a tiny fragment at an endpoint is taken as part of the perimeter CL finds, or you define by selection.

you keep saying this stuff but it's not curviloft which is failing..
unless you also consider sketchup itself is failing at creating a surface to my square in this scenario:

and your situation '2' is just poor user selection.. i'm not really sure what you're expecting the plugin to do in that scenario..

jeff hammond · 11 Jan 2014, 18:51

@yanosiento said:

guys, how could i make a surface from those contours? just a narrow face beetween the lines

http://s14.postimg.org/oebxw5ab5/d_vida.png

thnks

from the image you posted, it looks like all you would have to do is select all of it then use curviloft's skin contours function. (the 3rd icon in the toolbar)

TIG · 11 Jan 2014, 22:03

@Bruno

If none of the preceding comments apply or fix your issue... then please attach a SKP to a post and we'll look at it...

It will be 'do-able'...

jgb · 12 Jan 2014, 18:52

Jeff

You are being picky.

Of course the "fail to loft" is not a CL fault. It is the geometry faults that "prevent" CL from lofting.

oli_sketch · 23 Jan 2014, 21:38

Hello Fredo or someone who can help me.....

I have installed Fredo pluggins like Round Corner, Join Push Pull and curviloft on MACOSX 10.9.1 macbook pro 15" 2014 retina

When I use Fredo´s plugging Round Corner, Join Push Pull and curviloft the window with the different options and parameters are really, really small. Is impossible understand anything.

Can you help me ?

Kind regards

cotty · 24 Jan 2014, 07:01

It's a known problem with retina displays...

oli_sketch · 24 Jan 2014, 07:21

Thank you very much Cotty.

I´ll be waiting for a solution....

kind regards

cotty · 26 Jan 2014, 18:00

@oli_sketch said:

Thank you very much Cotty.

I´ll be waiting for a solution....

kind regards

You should share your details here, maybe it will help Fredo to find a solution ...

SamAxe · 8 Mar 2014, 16:57

Hello,
This is my first post.

I am having trouble skinning the curve that I have attached. Am I am doing something wrong?

I will appreciate any help.

I am running this on SU 2014 pro.

Thanks in advance. Appreciate all the help I can get.

-Sam

SkinTesting

TIG · 8 Mar 2014, 20:15

It is VERY faceted - several tens of thousands for potential facets !

The biggest 'arc' has 240 segments on its own...

Can you simplify the segmentation ?

mac1 · 9 Mar 2014, 07:31

Had some stray lines!
Also file is too large to load here see Dropbox link https://www.dropbox.com/s/xmtune9hovo9cqk/TestSkin11.skp used Fredo's Curviloft to skin and done using SU v8

mac1 · 9 Mar 2014, 08:15

TestSkin12.skpUsing TIG's suggestion reduced edges from ~670 to ~63 and used 'extrude edges by rails', as an alternative.
No noticeable difference, except model size is greatly reduced!

charly2008 · 9 Mar 2014, 12:26

Have a look at my post.

http://sketchucation.com/forums/viewtopic.php?f=15%26amp;t=56028%26amp;start=30

SamAxe · 10 Mar 2014, 10:36

Hello TIG & mac1,
Thank you very much for replying. As it is obviously evident, I am a newbie at not only sketchup but also mechanical drawing.

I have to sheepishly admit that I don't know what you mean by simplyfying the model or reducing the edges. How do I do that? If you can suggest some links I can read up on my own, and wont bug you guys with any more stupid problems borne out of my inexperience.

Thank you again.
-Sam

TIG · 10 Mar 2014, 14:22

A Circle or Arc has a number of segments.
These defaults can be seen in Entity Info [24 & 12 ?].
If the curve has not already been incorporated into a 3d form then you can adjust the segmentation for it there.
You can also change it as you create the Arc - e.g. type 6s +<enter> when you start the tool and the segment count becomes that.

Each segment is used to create an edge in a 3d form, so the more segments you have the more extra geometry is made. This affects performance as there are shadow casting/receiving to be calculated and material/textures to render etc...
This applies to native tools and plugin 'surface makers'.
The Circle default is 24s, so if you extrude that with PushPull you end up with 24+24+24 = 72 edges and
24+2 = 26 faces.
That will look smooth enough for most purposes.
It it were a handrail reducing it to say 12s would still probably look the same with hidden-geom off...
12+12+12 = 36 edges and 12+2 = 14 faces - a significant reduction in unneeded geometry...
If you foolishly increase it to say 360 [1 segment per degree!] it'll look little different from 24s AND you'll have a staggering 360+360+360 = 1080 edges and 360+2 = 362 faces

SO when you draw lines/curves that might become 3d objects think about the edge/face count that might result as they combine...

unearthed · 15 Apr 2014, 05:42

What an amazing plugin this is, Thanks very much Fredo

Anyway I'm drawing a model of part of a river for a planting design - there's no money for a surveyor so I drew cross sections and used Curviloft to loft between them using the streamline as the curve. All worked perfectly, BUT one section is a bit odd (a result of

straightening the channel) and I can't find a way of skinning between the profiles - is there a way in Curviloft, or would another tool do the trick? Due to the extrme bend of the stream it's hard to see a way of using new profiles between the existing one as a way to bridge the problem.

single skp enclosed - unzips to 4.5Mb

jgb · 15 Apr 2014, 13:44

You would probably do better if you connected the edges at the banks with a manually drawn curve. Then use the skinning function. Ignore (for now) the control curve path. I quickly tried this but it resulted in a partially bad curve. (See Attachment)

In doing complex skins as this that will not form right when tried as a whole piece, (airplane fairings for example) I found it better and quicker to split the perimeter in several easier sections, skin them, then explode them in place. Unfortunately, I have no time just now to do this for you.

Also, on the right side the edge is made up of a lot of small faces that really do not add any useful detail to the mesh. Simplify them, and it should make a better skin overall.

jeff hammond · 15 Apr 2014, 17:03

@unearthed said:

is there a way in Curviloft, or would another tool do the trick? Due to the extrme bend of the stream it's hard to see a way of using new profiles between the existing one as a way to bridge the problem.

ignore the bend line you have drawn in that section.. the way it's setup, it's going to result in bad geometry even if it did work.. if you really need that extreme of a bend then you'll have to figure out the profiles which would really work through there as the ones you have now won't do it.

probably just Loft that section instead using the two edges as the input (the edges in the image that are marked with a red & blue line) .. use the tension controls to obtain the bend while preventing overlaps..

unearthed · 15 Apr 2014, 19:57

Thanks Jeff - I may not need the extreme bend (If I do I'll draw contours between the sections and skin them with from contours)

and thanks too for showing a bit more about using Curviloft - I was really amazed when it lofted the individual stretches of stream (and gave the option to tweak the result).