REAL circles with DXF export?
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yeah TIG, my workflow is basically a version of what you're saying..
i usually draw my arcs with the arc:center&2pts. ruby and i like how it give the option for amount of segments (avoids a trip to the entity info box).. i start off with 96 segments. (and i don't know why 96.. i guess it's just a number i like
)i like your idea about moving a line up to 5' and then intersecting because i always use a construction line instead which means i then have to zoom in and find the actual intersection (which can be difficult when the segments are so close together).
after i have my arc at the right height, i'll right-click/divide it into 8inch segments (8" being my standard on-center layout).. i can then use those vertexes for other calculations i need to do such as:
everything always works out ok in the end but i was hoping something like this would be possible:
[flash=425,344:2uhcs32t]http://www.youtube.com/v/UMvdtFBb4pQ&hl=en&fs=1[/flash:2uhcs32t]that seems like the easiest/fastest/most accurate method
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i did some experimenting and everything is peachy now
sketchup CAN draw real circles (well, i don't know if other programs will see them as that but that aside, they are true circles)
for some reason, i always thought the maximum amount of segments you could divide an arc into was ~200.. i'm now able to divide them at 10,000+ (confirmed in both statistics and entity info) ... i tested around 10 of my normal sized radii with 2000 segment arcs and they all came up dead accurate (units set to decimal at .0001" precision..
see for yourself.. i draw an 8' arc twice - first with 12 segments then with 2000 segments.. pay attention to the radius lengths in the VCB..
[flash=500,425:2ycai699]http://www.youtube.com/v/VahW0X8ph1A&hl=en&fs=1[/flash:2ycai699]
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How have you the Window Box "Arc Parameter"? (is it Mac presentation different than PC?
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It's Didier's plugin : Arc
@unknownuser said:
Deux nouvelles méthodes de dessin d'arcs: arc passant par trois points, centre et deux points.
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Jeff
The detailed breakdown for a 96" radius circle is :-
128 segments >>> +/- 1/32" accuracy.
200 segments >>> +/- 1/64" accuracy.
256 segments >>> ~96" sometimes reported or circumference (the "~" tells us that it's not quite 96" by within 1/128" !).
689+ segments >>> 96" always reported (SketchUp simply gives up - it can't measure it any more accurately).Considering the degree of accuracy that can be achieved in physically building things in the real world, then a 200 or 256 segment circle (or proportional arc) would seem sufficient for most needs at most day-to-day sizes of things from a few inches to several yards...
I note that your arc had 2000 segments that's equivalent to a 8000 segment circle. Using thousands of edges gives no more benefit and loads the model disproportionately when used to pushpull etc...
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When you say 96" radius circle, is it 243.84 cm circle radius?
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@unknownuser said:
When you say 96" radius circle, is it 243.84 cm circle radius?
Exactly - I used inches for Jeff's sake...
[Exactement - j'ai employé pouces dans l'intéret de Jeff...]
1"=2.54cm
1/32"=0.794mm
1/64"=0.397mm
You can see the accuracy is negligible in 'real-world' terms - when did you ever make a physical model, piece of furniture or a building to such fine tolerances ?
[Vous pouvez voir que l'exactitude est négligeable en termes 'réels' - quand avez-vous jamais fait un maquette, le meuble ou un bâtiment à de telles tolérances fines ?]...
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Thx for the "precisions"
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yeah TIG, i think i'm being unclear with my intent here.. i'm not too concerned with being 100% precise in order to build accurately (for instance, our tapes are in 1/16" increments so i round to the nearest 16th for the cut lists)..
my concern is the method i previously had to go through in order to draw my arcs.. shown in the first half of this video --
[flash=500,400:ajuoc4zj]http://www.youtube.com/v/sCpbagJfGGQ&hl=en&fs=1[/flash:ajuoc4zj]
it can be a pain to get the point which i achieved at 0:25 in the video.. especially when using a laptop with no mouse as i often do on the jobsite..
you'll see though that i divide my arcs up into 8" segments and there's no way i'm thinking about using a 1000 segment arc for push/pull etc..
i just want to find the point where an 8' radius is 5' tall -- i'm not too concerned with having true circles in SU.. it's just that if they were true, i'd be able to find that point very easily.. by hyper-dividing them into thousands of segments, i can temporarily mimic a true circle and get my construction point..
(and yes, 2000 may be overkill -- that was just an experiment that happened to work out and i didn't try to find the minimum amount i should be dividing them at.. you're saying 689 segments works as well so i'll try something closer to that)
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