[Plugin] TIG-Smart_offset
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Error Again
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@blajnov said:
Error Again
the 48.4 dimension was not taken 'legitimately' (you should measure from the center of the arch segment perpendicular to offset segment)
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Two steps forward one step back...
Another 'fix' is in the mixer...
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hi tig,
just send something thru paypal, is 5 p. ok ?i am trying the offset-script, but have some problems, i cannot solve
drawing new curves : ruby works
in my actual project a have to insert lots of curves for landscape modelling.
i created a hole in an existing mesh >> extrqacted the borders of this hole >>
projected these border to a plane (sandbox) >> converted the borderline to- polygon
- curve
but somehow the script does not create offsets here (standard sketchup offset works - with all its mistakes)
i attach the planes, maybe you can check it
i work in skp 6
thanx and regards stan
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Thanks TIG,
I don't use a lot of plugins but I think this one will be very useful. Happy New Year to you.
Mike
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@Stan, any donation is more than welcome... I assume you meant Β£5 because 5p=~8Β’...
I think I have a fix for your probable issue - these 3m inset/outset offsets worked OK with a new version that I am working on [native fails with twisted parts].
It fixes some issues with multi-curve loops and also some curves that straddle a loop's start/end vertex not all offsetting as curves...
So far it seems to trap various permutations of offset size and loop contents and convolutions, that have been some unexpected causing issues...
I hope to have that version ready for release tomorrow...
![3m[native].PNG](/uploads/imported_attachments/kUxb_3mnative.PNG)
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Merry Xmas TIG. This looks awesome!
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Here's v1.7 http://sketchucation.com/forums/viewtopic.php?p=446462#p446462
Further glitches and convoluted offsets trapped.
I am hopeful this will address most issues reported to date...
Happy New Year !
[arriving shortly... ]
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TIG
Not to confuse the issue. Just how should and object look after an offset. I have attached two illustrations, showing an object that has two results. The first shows the object with an offset from your plugin, and the other showing the same object after scaling.
I certainly do not have the smarts to determine which is correct. However, I would suggest that the scaling illustration that shows the object retaining the basic shape would be the more correct solution.
Again, TIG thanks for all your work.
Ken
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The definition of an 'offset' is that all of the edges of the original face's 'outline' are replicated 'offset' perpendicularly by a fixed distance. In your illustration that is 'inwards'.
Clearly in the example made using my tool all of these new 'offset' edges are properly equidistant from the equivalent original perimeter edges.
In your 'scaling' example the new 'outline' is an exact replica of the original outline, it's only smaller is size, not 'offset'.
Therefore only some of these new edges are equidistant from their equivalents, the rest are further away by varying amounts.
Thus, the 'scaled' option gives a copy that's a shrunken version,: although it might be what you want, this is NOT what we are trying to do with an 'offset' - for that we want the 'walls' of the offset shape to be a consistent width; so for us the 'offset' option IS the correct tool to use...
Use can 'scale' to make smaller/larger exact 'copies' of a face's perimeter, BUT you need offset/Smart_offset to make proper 'offsets' of it... -
TIG
I understand that doing an offset, each edge would be offset to a set amount. However, some edges would disappear, and others would distort the shape.
Circular and rectangles shapes would be the only shapes that retained the original shape. With all others shapes the offsetting tool would have to make decision on how to modify the edges to give a close proximity to the original shape.
A real offset would have each edge offset the amount you select, and you would live with the results. Which may not be any where close to the original object's shape.
So my question was, if it OK to distort the shape, wouldn't a distortion of the offsetting parameters that still gives a close approximation to the original shape be better.
Note, I am not trying to change your plugin, I use offset quite a bit during modeling and will download and make a generous cookie offering. Certainly your plugin gives better results than the Sketchup offsetting tool.
It just occurred to me to ask myself, what am I trying to do when I offset and what are the acceptable results?
I generally use offsetting to establishment a edge internal or external to the object's edges for moving or setting another object. Very seldom do I use offsetting to get a larger or smaller version of the object.
I am done, so now everyone back to work.
Thanks TIG for your answer, you may start your break.
Ken
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Sometimes an offset must result in some edges in the original loop remaining unused.
If they have no viable vertices they aren't made.
Simple symmetrical shapes scale and offset with similar results, simple because the scaling is about a 'center'.
The difference between Scaling general shapes and an Offset are illustrated below.
You will see that my Smart_offset omits some edges in the most weird shape because they are 'cross-threaded' and no longer the requisite distance from the original edges...
Incidentally, in making this illustration I discovered a glitch where single welded curve perimeters [like the one around a circle] - these were failing to Smart_offset properly. I've fixed this and will post the update shortly... -
Here's v1.8 http://sketchucation.com/forums/viewtopic.php?p=446462#p446462
I noticed a glitch offsetting the 'outer_loop' of a face that was in the form of a single welded-curve [like a circle, ellipse etc].
This has been fixed.
Now a face with any type of single welded-curve 'outer_loop' should 'smart_offset' correctly.
I also fixed a typo in the offset-curve's 'welding-code', which then failed once the main issue was itself fixed.
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TIG,
This IS excellent! Something needed since SU began. I'll have to give it a try.
Happy New Year!
Peter
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@unknownuser said:
TIG
Not to confuse the issue. Just how should and object look after an offset. I have attached two illustrations, showing an object that has two results. The first shows the object with an offset from your plugin, and the other showing the same object after scaling.
I certainly do not have the smarts to determine which is correct. However, I would suggest that the scaling illustration that shows the object retaining the basic shape would be the more correct solution.
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@unknownuser said:
So my question was, if it OK to distort the shape, wouldn't a distortion of the offsetting parameters that still gives a close approximation to the original shape be better.
the shape isn't distorting in a real offset (though i guess i can see how you're thinking it is)..
imagine you draw the outline of, say, a building.. (and you can use your example image as an example of this as well)... now say you want to make a perimeter wall that is 12" thick.. what will the inside of the wall look like?
you're thinking the inner wall is a distortion of the shape you'd originally drew but when i see your scaled version which you may think looks right, i see a wall that's 12" thick in some spots, 24" thick in others.. and a variety of thicknesses in between.. (i.e.- definitely not an offset
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Jeff's point about Arc Offsetting is right AND wrong.
Offset/Smart_offset treat Arcs and Welded-Curves in the same way, their Segments are truly Offset.
If an Arc meets another Edge at a Vertex, then the segment of original arc-curve is properly parallel to the offset-curve itself, it will then appear 'angled' to other edges meeting the curve radially. However, if an Arc meets another Edge at the mid-point of a segment, then the segment of original arc-curve is still properly parallel to the offset-curve itself, it will then appear 'square' to other edges meeting the curve radially.
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TIG, your point about the arc and the way it meets the straight line is excellent. This angle frequently causes issues in Offset as well as other things like Follow Me. When I need the arc to start and end perpendicular to a line as shown on the right side of your illustration, I start with a circle and rotate it so there'll be perpendicular segments at the intersection. Then I cut the arc out of the circle. It would be nice if there was an Arc tool that could draw the arc that way from the beginning. I suppose it would only really be useful for half and quarter circles.
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The problem is having a circle intersect a line squarely is that the distance between the two parallel segments [taken across the circle] are not the circle's diameter apart; because a circle is 'inscribed', so then its vertices are on the circumference, only an intersection through two opposite vertices return the diameter. Any intersection s through segments result in the measurable 'diameter' across the intersection is reduced by just a little more than 0 [when the intersect in very near to the circle's vertices] up to ((diameter/2) * Math.cos(360.degrees/numseg/2)), when the segments' mid-points are both intersected [diameter/2==radius].
The more segments [numseg] there are then the nearer the two 'diameters' will get, but the square one will always be somewhat less that the true one, even with hundreds of segments... -
Yes, I realize that the flats aren't at the true radius of the arc. Very often for my use I wind up scaling the circle so when I dimension the arc, I am dimensioning to the midpoint of the edge parallel to the base. It isn't perfect but it gets the right information to the client and the difference isn't really apparent. I've developed a process that seems to work well enough manually so that I don't have to screw around with it for too long to get what I need.
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