# Rendering fails (difference between F5 and F6)

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## Re: Rendering fails (difference between F5 and F6)

 @Johan list comprehensions are what you're looking for. Special section on cheatsheet - http://www.openscad.org/cheatsheet/  look at "Generate" more info here: https://github.com/openscad/list-comprehension-demosFor rotation you could do something like this: function calc_rotation(from, step, to) = [ for (i = [from : step : to]) rotatie_top*i/100 ]; delta=4; echo(calc_rotation(0, delta, 100 - 4*delta)); giving: ECHO: [0, 1.8, 3.6, 5.4, 7.2, 9, 10.8, 12.6, 14.4, 16.2, 18, 19.8, 21.6, 23.4, 25.2, 27, 28.8, 30.6, 32.4, 34.2, 36, 37.8]
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## Re: Rendering fails (difference between F5 and F6)

 In reply to this post by Parkinbot This looks good. I hope they start printing now, but because I plan some other non lineaur stuff like mouthpieces I will try to find out how I get your functions doing my object. I will let you now. But maybe good to understand. What you do is define some points and rotation of one side of the object in A. Then you calculate a spline. Do I understand that a spline is an interpolation curve between the points in A. Is B then only an interpolated line? And does 100 mean the number of point you generate? Then you generate data. Does this make all the points of the object? Then you do a sweep. Does this fill the area between the points?
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## Re: Rendering fails (difference between F5 and F6)

 In reply to this post by Johan Jonker Probably on a totally different tangent, why do you want to model the horn/bell of a Bass Clarinet?? I am interested in music and play in a community orchestra.  The Bass Clarinetist has probably THE most expensive instrument and it a really interesting instrument so for all the "non SCAD" reasons I am interested in your aims.  Could you elaborate please (in a quick way that does not clog up this discussion) what the project is about, or is it just a theoretical investigation??? Cheers, Rob On 09/12/15 08:54, Johan Jonker wrote: ```A strange problem. F5 gives a good result (see first image). F6 seems to forget the main part of the object. This is my code: / difference() { union() { difference() { import("C:\\Users\\Eigenaar\\Documents\\Mijn 3D design\\basklarinetbeker buiten v4.stl", convexity = 5); import("C:\\Users\\Eigenaar\\Documents\\Mijn 3D design\\basklarinetbeker binnen v4.stl", convexity = 5); } translate([0,0,-155]) { cylinder(5,(d_btm_inside +d_btm_wall/2)/2, (d_btm_inside +d_btm_wall/2)/2); } } translate([0,0,-160]) cylinder(11,d_btm_inside/2, d_btm_inside/2); }/ F5 result: F6 result: -- View this message in context: http://forum.openscad.org/Rendering-fails-difference-between-F5-and-F6-tp15041.html Sent from the OpenSCAD mailing list archive at Nabble.com. _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org ``` -- Rob Ward Lake Tyers Beach, 3909 Lake Tyers Beach Website XP to XUbuntu - The journey, join me! _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org Rob W Lake Tyers Beach, Victoria, Australia
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## Re: Rendering fails (difference between F5 and F6)

 Hello Rob, I am repairing saxophone for a few years now and was interested in repairing bass clarinets too because I started to play the instrument a year ago. I practice repairing by buying cheap instruments and fix them and then sell them. I bought a bass clarinet without a bell and neck a mounth ago. Because it was a plastic bass clarinet I thought that it would interesting to print the quite expensive bell and see what the results would be. When I tried to make the first designs I was infected by the 3D virus. I don't know how to cure from that ;-). I have a lot of other things in mind: a bass clarinet extension from low Eb to low C for instance. regards, Johan
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## Re: Rendering fails (difference between F5 and F6)

 We may need to start a new thread Johan, but that is very interesting to me.  The technicalities of rendering an instrument that has been worked out by people with exquisite musical sensory faculties eg Stradivarius,  just to quote one very famous one, is very intriguing.  It is also tantalising to think, if the experts of old could be paralleled by modern technology, and especially the recent trigonometric precision of the combination of a software package like 'openSCAD' and a 3-D printer, whether anything can  be improved, or maybe just happy to be replicated? My fascination with the shapes of instruments and a fairly primitive knowledge of trigonometry and other functions etc makes me wonder what is possible? OpenSCAD may have to start a 'counseling' thread for people trying to not think of their daily lives being consumed by the thought "now, if only I could print.....". Returning to your challenge.  Changing the tuning would be awesome, and a huge challenge (mainly for the challenges mentioned above). To alter the bell and still rely on the established keying structure of the rest of the instrument, ie not have to rebuild the whole thing, would be very difficult would it not??? Maybe one day in openSCAD one could produce the Stradivarius.stl and make one!  Cheers Rob On 12/12/15 23:07, Johan Jonker wrote: ```Hello Rob, I am repairing saxophone for a few years now and was interested in repairing bass clarinets too because I started to play the instrument a year ago. I practice repairing by buying cheap instruments and fix them and then sell them. I bought a bass clarinet without a bell and neck a mounth ago. Because it was a plastic bass clarinet I thought that it would interesting to print the quite expensive bell and see what the results would be. When I tried to make the first designs I was infected by the 3D virus. I don't know how to cure from that ;-). I have a lot of other things in mind: a bass clarinet extension from low Eb to low C for instance. regards, Johan -- View this message in context: http://forum.openscad.org/Rendering-fails-difference-between-F5-and-F6-tp15041p15126.html Sent from the OpenSCAD mailing list archive at Nabble.com. _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org ``` -- Rob Ward Lake Tyers Beach, 3909 Lake Tyers Beach Website XP to XUbuntu - The journey, join me! _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org Rob W Lake Tyers Beach, Victoria, Australia
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## Re: Rendering fails (difference between F5 and F6)

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## Re: Rendering fails (difference between F5 and F6)

 Administrator In reply to this post by Johan Jonker Hi all, I haven’t had the time to digest the last long email threads, but in this particular case, has anyone looked at the skin() function in list-comprehension-demos? https://github.com/openscad/list-comprehension-demos#extrusionscad..it could be easier to use than doing a sweep.  -Marius _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
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## Re: Rendering fails (difference between F5 and F6)

 Things like skin.scad look really interesting but I can't figure out how they are supposed to be used, by just looking at the code. (e.g. augment_profile augments the profile with Steiner points. but what...?) Is it possible to make some samples files which exercise all the aspects of each of these files in the list_comprehensions folder ?
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## Re: Rendering fails (difference between F5 and F6)

 On 12/13/2015 07:19 AM, Neon22 wrote: > Is it possible to make some samples files which exercise all the aspects of > each of these files in the list_comprehensions folder ? > Some examples are a bit hidden in: https://github.com/openscad/list-comprehension-demos/blob/master/extrusion.scadciao,   Torsten. _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org -- Torsten
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## Re: Rendering fails (difference between F5 and F6)

 In reply to this post by kintel   kintel wrote ..it could be easier to use than doing a sweep. This heavily depends on what kind of sweep() or skin() you use. Don't know whether you have looked at the code? I am using an own version from NacaSweep.scad described here, which is much more basic than the "official" one you might know, as it knits just a matrix (a vector of vectors describing a series of non-intersecting polygons already placed in 3D space) into a polyhedron. Before I decided to implement this version, I tried out the "official" one and found it too complicated and restricted for my purposes - beside the lack of documentation also in code. Rudolf
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## Re: Rendering fails (difference between F5 and F6)

 Administrator > On Dec 13, 2015, at 08:18 AM, Parkinbot <[hidden email]> wrote: > Before I decided to implement this version, I tried out the "official" one > and found it too complicated and restricted for my purposes - beside the > lack of documentation also in code. > Nice - I’ll try to have a look. The purpose of the “official” sweep and skin is to explore the functionality and interface of such functions, in order to make better decision when eventually creating built-in and long-term supported implementations of it. If you could provide some insights into what you need, what was missing in the original implementation etc., that would be very helpful.  -Marius _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
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## Re: Rendering fails (difference between F5 and F6)

 kintel wrote If you could provide some insights into what you need, what was missing in the original implementation etc., that would be very helpful. I never played around with skin(). But as far as I remember, I didn't like the interface of sweep(), as its prototyp was too restricting. I'm talking about this one module sweep(shape, path_transforms, closed=false) 1. It doesn't allow for a parametrization of *shape*, 2. It restricts *path-transforms* to finite operations 3. I'm not a friend of multmatrix and representations of similar complexity So I decided to reimplement it, just demanding a regular matrix - which represents a series of polygons in 3D-space as already mentioned. This series may be freely composed: using any kind of transformations, finite and non-linear in any order, interpolation schemes (e.g. nSpline()) and unlimitedly parametrized shapes (e.g. airfoils with non-linear transitions along the path). See my example of a loop propeller (also just a fast scetch for this post), using a 7D interpolation. I guess you can read my shortcuts: R, Rx, Tx and so on operate over objects, Rx_ Tz_ and so operate over vectors (shapes) and without interpolation C = gen_dat(A, 100);   // generate data you'll still get this
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## Re: Rendering fails (difference between F5 and F6)

 Administrator On Dec 13, 2015, at 15:34 PM, Parkinbot <[hidden email]> wrote: > So I decided to reimplement it, just demanding a regular matrix - which > represents a series of polygons in 3D-space as already mentioned. This sounds exactly like skin(), as used here: https://github.com/openscad/list-comprehension-demos#forma-candle-holderscadDoes that differ in any way, if so, what are you missing from skin()? (I didn’t have the chance to read your code yet)  -Marius _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
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## Re: Rendering fails (difference between F5 and F6)

 In reply to this post by Johan Jonker Hi Maybe you are interested in this: https://www.youtube.com/watch?v=MWa8sEgpOrM
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## Re: Rendering fails (difference between F5 and F6)

 In reply to this post by kintel kintel wrote Does that differ in any way, if so, what are you missing from skin()? (I didn’t have the chance to read your code yet) Meanwhile I had a look at your skin() example. You are right, obviously skin() and my sweep() are at least syntactically interchangeable and give the same results on my examples - however the implementations differ a lot. Is/was it part of any libary? Anyway, in environments without debugging facilities I always prefer to use my own code :-) @jpmendes Hey, this film shows only E-guitars. No 3D-acoustics involved :-(
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## Re: Rendering fails (difference between F5 and F6)

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## Re: Rendering fails (difference between F5 and F6)

 @jpmendes Thingiverse user mechadense has done some great work on horns. http://www.thingiverse.com/thing:218241Just needs a bit mor ework to finish it up for general OpenSCAD use... (hint :))
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## Re: Rendering fails (difference between F5 and F6)

 Administrator In reply to this post by Parkinbot > On Dec 14, 2015, at 15:53 PM, Parkinbot <[hidden email]> wrote: > > Meanwhile I had a look at your skin() example. […] > Is/was it part of any libary? It’s part of the exploration of new functionality. I’m interested in whether this is a good function to offer, what sort of added/changed features are needed and interface ideas.  -Marius _______________________________________________ OpenSCAD mailing list [hidden email] http://lists.openscad.org/mailman/listinfo/discuss_lists.openscad.org
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## Re: Rendering fails (difference between F5 and F6)

 kintel wrote .... I’m interested in whether this is a good function to offer, I guess you know that my answer will be yes. Connected with an interpolation scheme it is really powerful. kintel wrote what sort of added/changed features are needed and interface ideas. I just had a look, how skin() behaves when it has to connect polygons with different number of points (mine doesn't do that at all for a good reason). The result is somehow unexpected. use use use use r=50; height=140; layers = 2;   skin([for (i=[0:layers-1])         transform(translation([0,0,i*height/layers]) * rotation([0,0,-0*i]), circle(\$fn=6+2*i,r=r))]); Why would one split the lines of a polygon? Is this semantics a hack? I'd expect unpaired triangles as natural semantics. And I would also expect the result to be convex (at least in this case). And an immediate feature request would be: adding furcations like a bifurcation and an inverse (anastomosis) to it. a bifurcation matrix would be [... [...], [...], [[...], [...]], ...] and the inverse: [... [[...], [...]], [...], [...], ... ] It is easy to calculate furcations, but hard to connect them in a proper way using OpenSCAD language means. - Rudolf -