To find intersection point of a selfintersecting bspline. I often use svgimported beziers to create the geometry, and frequently i have problems with self intersecting bezier curves. When i try to extrude this closed polyline yes it is closed i get the message cannot sweep or extrude a selfintersecting curve. Can anyone please help me to find the intersection point of a self intersecting bspline curve. The pdq np is a plugin for nx that provides instant cad model checking, healing, and certification. All crossing intersections and selfintersecting curves are rejected. Modeling uncertainty the bodies or surfaces have low. I cannot sweep or extrude a selfintersecting curve.
Sometimes a model can become damaged and the damaged areas can cause problems. Jan 27, 2011 nx hints and tips extrude with intersecting section curves in one feature siemens software. Geometry errors selfintersecting surfaces a surface that folds onto itself is a. I am trying to create a cad drawing for the construction of paddle pop sticks. It is possible to build bad models using rhino tools. We often will xref our first floor plans onto our second floor plans and then create a rather involved pline to use as a. The bottom pices are what i have broken it into and joined as polylines for extrusion.
Ive tried region based and part based meshing, i believe. Since the boundary curve is offset in a threedimensional 3d space, the local self intersection in the offset curve is addressed in a 2d space by approximately mapping the offset vectors in the. I often use svgimported beziers to create the geometry, and frequently i have problems with selfintersecting bezier curves. Instead of having to painstakingly tweak a curve with thousands of small segments, you position a few control. A 3d sketch opens because you clicked before selecting a plane. Cad forum fix problem of areas on selfintersecting.
I did have an issue with the symmetry plane that cuts the center of the car. Saving and reopening the drawing later, will no longer indicate the unresolved. Be careful with file tolerance, it also finds parts of the same curve folded back on itself that are nearer than file tolerance but dont necessarily cross mitch. Straight lines conic sections freeform parametric curves bsplines, nurbs curves of intersection between surfaces defined during model construction curve use in design. Intersecting curve an overview sciencedirect topics. The 3d spline curve is selfintersecting solidworks forums. Can anyone please help me to find the intersection point of a selfintersecting bspline curve. The way to identify these issues is through going to repairidentify self intersecting surfaces. With a part open, click intersection curve on the sketch toolbar, or tools sketch tools intersection curve. Because you selected object and it didnt work im betting a selfintersecting curve. This is a great way to create ribs or similar features without having to extrude lines separately. Autocad civil 3d illegal selfintersecting or nonclosed. Selfintersecting curves curve data comprises lines, arcs, or splines. Geometry and topology error reference repair and construction.
Fixing selfintersecting curves for extrusion i have been working on this project for awhile, trying to get it to extrude. To find intersection point of a selfintersecting bspline curve. Ideally, the cad program exports a sphere and a cube without having the interior overlap highlighted in the picture below. Curves in modeling curves produced in modeling systems. I then exploded closed and opened a few of the separate curved elementsrejoined and for some reason autocad now sees it as extrudable so i am back to work. I replaced your curve with a smooth one and performed the sweep with no problems. Can produce self intersecting curves easy to determine whether a given point lies on the line set. So,i want to find the intersection point in order to trim. I tried the lisp but it told me the same thingcant extrude self intersecting curve. Use the curve to create shapes such as those used in consumer products, piping, and to control the shape of complex lofts.
Cad forum fix problem of areas on selfintersecting curves in autocad 20. Beginning in the 1980s, cad software reduced the need for draftsmen significantly, especially in small to midsized companies. I understand why its self intersecting, but i have no choice, this is the curve shape i must work with, and i must use this surface to trim solids with. Mike carter shares a trick he developed to deal with selfintersecting clip boundaries. An open selfintersection is a selfintersection that occurs inside a. How to find lines in a network that self intersects. My question is how can we prove that the curve does in face self intersect, and, if possible, find the coordinates of a particular intersection point a general formula would be lovely, but it seems like a far shot. To use the sketched curve to extrude a feature, the sketch that opens must be a 2d sketch. I cannot sweep or extrude a self intersecting curve. Beginning in the 1980s, cad software reduced the need for draftsmen. Identifying selfintersection points in one parametric. Figure 44 shows a tubing performance curve intersecting a well deliverability inflow curve inflow performance curveipr. Some dwg drawings may contain curves polylines with selfintersecting segments creating loops, or polylines containing duplicate vertices.
Surfaces must be continuous and smooth without changing direction. I have a rather strong feeling that this is really easy but im not getting how for some reason. Question asked by samuel pinckney on oct 6, 2017 latest reply on oct 7. Click 3d sketch tab draw panel intersection curve to create a 3d curve. Caddoctor for nx enables both the nissan and the supplier to validate and secure the quality of all. The figure shows the tubing curve intersecting the inflow curve in two. Here is an older vb script from my library for selecting self intersecting curves and marking the intersection points. I cut a linear pattern of spacer grids with mixing vanes through a channel to study subchannel thermal hydraulics in modular pwrs. To open a 3d sketch, click intersection curve first then select the plane. A great new piece of functionality in the extrude tool allows the user to extrude self intersecting curves. The problem is that the obtained bspline curve is self intersecting.
I import xy points quite often to create camshaft profiles, but recently had an issue that i cant explain. Im getting this message sometimes when i try to extrude objects with lots of curves and arcs. This applies only to selfintersecting faces, not two different faces of the same feature that intersect. Self intersecting curves curve data comprises lines, arcs, or splines. Split and trim curves and surfaces linkedin learning. When using a cadsystem for designing geometric objects, youll find. Finally the selfintersection points are approximated by. To open a 2d sketch, select the plane first then click intersection. If this message is ignored, the drawing dimensions may not update correctly. Nx hints and tips extrude with intersecting section. My question is how can we prove that the curve does in face selfintersect, and, if possible, find the coordinates of a. For instance, if you trim a surface with a selfintersecting curve, rhino will let you do it, but the result will be a poorly defined model that causes.
Apr 29, 2010 after i created the 30degree work plane i started a 3d sketch and got an intersection curve between the solid and the work plane. I made a program that graphs a figure 8 using equations, and it outputs a single curve. Since the boundary curve is offset in a threedimensional 3d space, the local selfintersection in the offset curve is addressed in a 2d space by approximately mapping the offset vectors in the. Command locator crashing autocad if a custom ribbonsplitbutton is present main. I cut a linear pattern of spacer grids with mixing vanes through a channel to. Discussions about mcneel related software products rhino3d, grasshopper, flamingo, bongo, brazil, neon. Geometry errors selfintersecting surfaces a surface that folds onto itself is a selfintersecting surface. Such polylines with nonstandard geometry may cause different problems when processing. We often will xref our first floor plans onto our second floor plans and then create a rather involved pline to use as a clipping boundary for the xclip command to mask off parts of the first floor xref that we dont want to be visible on the second floor. This applies only to selfintersecting faces, not two different faces of the same feature. Any ideas what a self intersecting curve looks like. Pedit command edit a vertex abdusing the next option to walk arond. Userwish 7 siemens nx 9 training wrap curve duration.
If checked, a polyline frame will be displayed connecting the curve s control points. Nx hints and tips extrude with intersecting section curves in one feature siemens software. Net block insertion along closed polyline aug 3, 2011. When the radius of a fillet is set to or when there is no angle set to a chamfer, these tools can be used to clean intersections by trimming or extending objects at their intersections. Autocad 3d self intersecting surface while sweeping. It is possible to build bad models using rhino tools for. Free product trials 3d cad software civil engineering drafting. Geometry errors self intersecting surfaces a surface that folds onto itself is a self intersecting surface. Each cad and any associated text, image or data is in no way sponsored by or affiliated with any company, organization or realworld item, product, or good it may purport to portray. I do this sort of extrusion all the time closed polylines with. Slice the sweep in two halves, in order to create a selfintersecting compound. I got it to work for a few models earlier, but once i added a fin to the solidworks model and tried to run it again, it started giving me the. Apr 05, 2016 i made a program that graphs a figure 8 using equations, and it outputs a single curve. For the life of me, i cant figure out why so many ask questions without providing enough information.
Inventor doesnt allow it but other software allows you to change the sketch of the bend during creation, but with inventor you need to draw it before hand. May 20, 2009 in the properties dialog for curve, on the curve page, checkmark show frame. As you draw your curve, it places a polyline between the points. How to extrude a selfintersecting or curves drawing into 3d. I had a look at thelarge outer polyline and it appeared ok using the. I noticed that geometry size was very large which made me. I check the mesh in rhino and rhino reports its fine. Tagged withboolean, cad, curves, design visionaries, design viz. Selfintersection detection and elimination in freeform. This prevents automated programs from posting comments. I would like import this surface topography text file as 3d curve to designmodeler, but i get the following error.
Sheet metal self intersecting flanges error autodesk. Finding selfintersections on a polar curve mathematics. The first example of global selfintersection elimination is illustrated in fig. Most of the problems i can spot and correct in inkscape after. Oct 31, 20 autocad 20 selfintersecting curves for extrusion oct 31, 20. I am trying to import coordinate points to design modeler to get a curve. Fix problem of areas on selfintersecting curves in autocad 20 the command area in autocad 20 old, no more referenced from menu does not report proper area of polylines containing intersecting. Then i start a 2d sketch on my 30 degree work plane, project the edge i want from the 3d sketch and offset it whatever i want my gap to be.
Any ideas what a selfintersecting curve looks like. I have created a text file which contains 5 columns. Cannot sweep or extrude a selfintersecting curve autocad 3d. A control point curve is a freeform curve that is controlled by a limited number of control points. The model below is a good example of intersecting surfaces. Selfintersecting polylines and polylines with duplicate vertices. For instance, if you trim a surface with a self intersecting curve, rhino will let you do it, but the result will be a poorly defined model that causes problems later. Catia is a worldclass 3d software that incorporates computeraided design cad, computeraided manufacturing cam, and computeraided. Faces, surfaces, or the entire part body 2d sketch curves work planes on the ribbon, click 3d model tab sketch panel create 3d sketch.
Selfintersecting loop found in this profile prevents dimension values in inventor drawing products and versions covered inventor 2018, inventor 2019, inventor lt 2018, inventor lt 2019, inventor. This applies only to self intersecting faces, not two different faces of the same feature that intersect. In selection info, check show frame in the curve section. Autocad 2014 self intersecting polylines autocad tips. The computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. Apr 14, 20 with autocad 2014 you now have the ability to use the fillet or chamfer commands on a polyline that is selfintersecting. Im not at all suggesting that things should be done this way, since it will be decidedly slow, and the undocumented findintersections function is apparently a little unreliable, but i thought the following. Extrude option does not work in autocad 2010 software and shows the error message that cant sweep or extrude selfintersecting curves. Model complex 3d architectural geometry with rhinoceros. How to extrude a selfintersecting or curves drawing into. With autocad 2014 you now have the ability to use the fillet or chamfer commands on a polyline that is. Besides drawing a geometric model with the cad tools built into comsol multiphysics, an alternative is to create it with a specialized cad software application and save it to a fileone that the.
A shell selfintersection is an intersection between different surfaces in the shell. I have the option to change the bounds, so i can print out a half finished 8 or just a half of the 8, but i. Cad forum selfintersecting polylines and polylines with. Jan 26, 2014 because you selected object and it didnt work im betting a self intersecting curve. The figure shows the tubing curve intersecting the inflow curve in two places. A great new piece of functionality in the extrude tool allows the user to extrude selfintersecting curves. The result is a surface thats self intersecting that i cant trim other solids with. I would like to detect if a certain polyline is selfintersecting and if so i would like to compute those intersection points. To open a 2d sketch, select the plane first then click intersection curve.
The top drawing of the shape is when i created it, still as lines and arcs. Most of the problems i can spot and correct in inkscape after many minutes of staring at the curves in full zoomin, but i wish there was a way to do this automatically though, because if it feels like a tedious, repetitive task that could be automated and optionally. Fix problem of areas on selfintersecting curves in. Mar 31, 2018 the computeraided design cad files and all associated content posted to this website are created, uploaded, managed and owned by third party users. Autocad 3d self intersecting surface while sweeping dec 12, 2011. Question asked by alan thomason on jul 24, 2014 latest reply on jul 27, 2014 by alan thomason.
Remove the intersection by adding a sketch point at curve intersections or by changing nonprofile geometry to construction geometry. Hi i keep getting the above error but the curve does not intersect. Intersections in cad when using a cad system for designing geometric objects, youll find inside the cad system extensive use of intersection algorithms to determine which parts of curves and surfaces describe the shells of the volume, and to establish the correct relation between points, curves and surfaces used in the description. Aug 29, 2019 when performing a series of surface commands in nx 11. Identifying selfintersection points in one parametric graph.
I do this sort of extrusion all the time closed polylines with various geometry and usually have no trouble. May 01, 2012 when i try to extrude this closed polyline yes it is closed i get the message cannot sweep or extrude a self intersecting curve. Nx hints and tips extrude with intersecting section curves. The software s affordability and ability to run on personal computers in the mid1990s allowed engineers to do their own drafting and analytic work to some extent.
I have been working on this project for awhile, trying to get it to extrude. For the life of me, i cant figure out why so many ask. I got it to work for a few models earlier, but once i added a fin to the solidworks model and tried to run it again, it started giving me the same self intersecting geometry errors despite having no pierced faces. In order to make sure that each pair t1, t2 corresponds to the same intersection, and that we have found them all, and that they are correct, we can plot the points together with the original curve. I have the option to change the bounds, so i can print out a half finished 8 or just a half of the 8, but i didnt make a maximumminimum value for the bounds, so theoretically i could make the curve draw over itself an infinite number of times. The curve where the surfaces meet will be an edge in the cadmodel to be found by intersecting the surfaces. Region command autocad 2020 autodesk knowledge network. As previously pointed out, the selfintersection is to be expected. Curve representation all forms of geometric modeling require the ability to define curves.
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