Convert Rhino.Geometry.NurbsCurve to Autodesk.Revit.DB.NurbSpline - Grasshopper2024-03-28T11:06:09Zhttps://www.grasshopper3d.com/forum/topics/convert-rhino-geometry-nurbscurve-to-autodesk-revit-db-nurbspline?commentId=2985220%3AComment%3A1693876&feed=yes&xn_auth=noWell the few times that I nee…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16940112017-02-17T22:48:14.782Zkonrad k sobonhttps://www.grasshopper3d.com/profile/konradksobon
<p>Well the few times that I needed to convert between Nurbs in other applications and Revit i used what Jon has advised. Basically check if curve is degree 3 and has the right amount of control points etc. If direct conversion failed I always reverted to using an approximation using Splines. Note that splines and nurbs in Revit are limited since they can't be closed for example hence there is no way to use them for such simple operations as profiles for extrusions etc. Revit has a very…</p>
<p>Well the few times that I needed to convert between Nurbs in other applications and Revit i used what Jon has advised. Basically check if curve is degree 3 and has the right amount of control points etc. If direct conversion failed I always reverted to using an approximation using Splines. Note that splines and nurbs in Revit are limited since they can't be closed for example hence there is no way to use them for such simple operations as profiles for extrusions etc. Revit has a very limiting geometry library that is not compatible with any other standard out there. Sorry mate. </p> Yes, Revit has a constrained…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16937052017-02-17T22:17:10.961ZJon Mirtschinhttps://www.grasshopper3d.com/profile/JonMirtschin
<p>Yes, Revit has a constrained capability with regards to nurbs (Such as your note above about degree 2, or the number of control points).</p>
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<p>The Geometry Gym Revit plugin rebuilds a hermite spline by fitting points in the case that direct conversion fails.</p>
<p>Yes, Revit has a constrained capability with regards to nurbs (Such as your note above about degree 2, or the number of control points).</p>
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<p>The Geometry Gym Revit plugin rebuilds a hermite spline by fitting points in the case that direct conversion fails.</p> Thanks Jon I will take a look…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16936962017-02-17T21:38:21.739Zmichael sprinzlhttps://www.grasshopper3d.com/profile/Sprinzl
<p>Thanks Jon I will take a look. I tryed this with 1 extra in front and in the end but i have still probs with some Curve definitions ... I will update the Issues</p>
<p>List<double> KnotsNew = new List<double>();<br/> KnotsNew.Add(knots.First());<br/> KnotsNew.AddRange(knots);<br/> KnotsNew.Add(knots.Last());</p>
<p><br/>Thanks Jon.</p>
<p>Thanks Jon I will take a look. I tryed this with 1 extra in front and in the end but i have still probs with some Curve definitions ... I will update the Issues</p>
<p>List<double> KnotsNew = new List<double>();<br/> KnotsNew.Add(knots.First());<br/> KnotsNew.AddRange(knots);<br/> KnotsNew.Add(knots.Last());</p>
<p><br/>Thanks Jon.</p> The definition of a nurbs cur…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16939602017-02-17T21:35:53.269ZJon Mirtschinhttps://www.grasshopper3d.com/profile/JonMirtschin
<p>The definition of a nurbs curve in Revit in comparison with OpenNurbs is only differing in that Revit uses a definition with two additional knots, so make sure you add a duplicate of the first and last in your conversion.</p>
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<p>Note that often Revit errors and warnings are misleading and unrelated to that actual issue. There are a few topics on this on the revit api forum (such as this one). …</p>
<p>The definition of a nurbs curve in Revit in comparison with OpenNurbs is only differing in that Revit uses a definition with two additional knots, so make sure you add a duplicate of the first and last in your conversion.</p>
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<p>Note that often Revit errors and warnings are misleading and unrelated to that actual issue. There are a few topics on this on the revit api forum (such as this one). <a href="https://forums.autodesk.com/t5/revit-api-forum/nurbspline-creation-error/m-p/4831565/highlight/true#M5718" target="_blank">https://forums.autodesk.com/t5/revit-api-forum/nurbspline-creation-error/m-p/4831565/highlight/true#M5718</a></p> I already decomplied Grevit t…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16937742017-02-17T21:27:04.084Zmichael sprinzlhttps://www.grasshopper3d.com/profile/Sprinzl
<p>I already decomplied Grevit to look for the solution. It just uses the Weight and Points no complex Curves with knots are implemented.No solution yet....</p>
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<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/2769246219?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/2769246219?profile=RESIZE_1024x1024" class="align-left" width="721"/></a></p>
<p>I already decomplied Grevit to look for the solution. It just uses the Weight and Points no complex Curves with knots are implemented.No solution yet....</p>
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<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/2769246219?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/2769246219?profile=RESIZE_1024x1024" class="align-left" width="721"/></a></p> No, I don't think there is an…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16938762017-02-17T20:47:44.410Zkonrad k sobonhttps://www.grasshopper3d.com/profile/konradksobon
<p>No, I don't think there is anything. Revit API SDK is the closest thing to documentation that you will find, but it doesn't address any of your questions. Rightfully so, its for Revit API itself. I don't think anyone has ever put such document together. The best solution would be to look under the hood of plugins like Grevit which are Open Source. They deal with exactly your problem, so you can see how. </p>
<p>No, I don't think there is anything. Revit API SDK is the closest thing to documentation that you will find, but it doesn't address any of your questions. Rightfully so, its for Revit API itself. I don't think anyone has ever put such document together. The best solution would be to look under the hood of plugins like Grevit which are Open Source. They deal with exactly your problem, so you can see how. </p> Jepp for example Revit does n…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16937382017-02-17T17:47:13.572Zmichael sprinzlhttps://www.grasshopper3d.com/profile/Sprinzl
<p>Jepp for example Revit does not have degree 2 or 1. So Forward and Backward serialization will not be without loss. But still is here any documatation about the differences in the Curve Models?</p>
<p>Jepp for example Revit does not have degree 2 or 1. So Forward and Backward serialization will not be without loss. But still is here any documatation about the differences in the Curve Models?</p> Many papers talks about inter…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16938302017-02-17T17:16:08.691ZJohnhttps://www.grasshopper3d.com/profile/TomSholt
<p>Many papers talks about interoperability that nurbs , curves and meshes are not the same in different software. No wonder why revit and rhino have different data structures.</p>
<p>Many papers talks about interoperability that nurbs , curves and meshes are not the same in different software. No wonder why revit and rhino have different data structures.</p> The size of knots must equal…tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16938162017-02-17T15:51:42.922Zmichael sprinzlhttps://www.grasshopper3d.com/profile/Sprinzl
<p>The size of knots must equal the sum of degree, the size of the controlPoints array and 1. The first degree+1 knots should be identical, as should the last degree+1 knots. <strong>Revit</strong> requires the knots in the middle of the sequence to be increasing.<br/>Parameter name: knots<br/><br/></p>
<p>The size of knots must equal the sum of degree, the size of the controlPoints array and 1. The first degree+1 knots should be identical, as should the last degree+1 knots. <strong>Revit</strong> requires the knots in the middle of the sequence to be increasing.<br/>Parameter name: knots<br/><br/></p> tag:www.grasshopper3d.com,2017-02-17:2985220:Comment:16938122017-02-17T15:43:50.165Zmichael sprinzlhttps://www.grasshopper3d.com/profile/Sprinzl
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/2769246451?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/2769246451?profile=RESIZE_1024x1024" class="align-center" width="721"/></a></p>
<p><a href="http://storage.ning.com/topology/rest/1.0/file/get/2769246451?profile=original" target="_self"><img width="721" src="http://storage.ning.com/topology/rest/1.0/file/get/2769246451?profile=RESIZE_1024x1024" class="align-center" width="721"/></a></p>