Mr. Tonci Pirovic 3 Report post Posted April 3, 2014 Hi All, it's nice to be part of FFW / CAESES forum! I'd appreciate your advice on some ideas I've been playing with for some time now... For the all curved transverse section I'd like bottom to be part of an ellipse, connecting to upper curve with G2 continuity. Furthermore, I'd like to control the position of the inflection point of the upper curve ( with some basic curves for example, for construction of the hull metasurface...) Still not sure about bilge area up to waterline, but I should be able to control immersed sectional area of the wet curves combination... Thanks in advance!Tonci Share this post Link to post Share on other sites
Mr. Claus Abt 14 Report post Posted April 3, 2014 HI Tonci,If you use an fspline to extend the ellipse, you can set the curvature myfspline.startcurvature(myellipse.getcurvature(1,0)). Sorry, this is hidden functionality beacuse curvature is not always easy to control and the fspline might not find a solution. But I use it quite often and it usually works. For the inflection point you have a good chance if you do not restrict the end condition of the fspline, except the location. CheersClaus Share this post Link to post Share on other sites
Mr. Claus Abt 14 Report post Posted April 4, 2014 Here you find a small example setup. There are two points, one at the inflection the other one at the deck. Please select them and move them around. The zero curvature should stay more or less at the inflection point. Claus sectionExample.fdb Share this post Link to post Share on other sites
Mr. Tonci Pirovic 3 Report post Posted April 4, 2014 Hi Claus, thank you very much on swift answers! This is very fine example of the powerful fspline features. Combining techniques you suggested, it is possible to obtain very nice and usefull sectional shapes... Share this post Link to post Share on other sites
Mr. Mattia Brenner 6 Report post Posted April 24, 2014 Hi Tonci, here is some more input about curve definitions that will hopefully give you some additional ideas. I am often using combinations of FSplines. For longitudinal curves, I often use a feature that I created called "Multi-segmented Smooth Curve" (you can find it in the features menu under "Hull Design").Based on the basic procedure used in that feature, one can think of several possible improvements. E.g. I have added the option of setting C2 continuity at the joint between the segments (see feature "CurveAdvancedGenericBasic" in the attached ZIP file).Another thing I tried, is to automatically determine a reasonable tangent at the middle point of a two-segmented curve by using the mean tangent of two FSplines coming from both sides (see the feature in the attached project file "smartSectionDefinition", btw: not only useful for sections). Cheers,MattiasmartSectionDefinition.fdbCurveAdvancedGenericBasic.zip Share this post Link to post Share on other sites