Bella_Ciolla Posted February 11, 2009 Share Posted February 11, 2009 Hello, I am new but have a question about edgesurf command. Its not necessarily about how to use it etc, I know all that, but does anybody know the math behind the edge surf? which happens to be a 'coons patch' I am not a mathematician but I have been researching and know almost everything about the math behind it except I dont understand the math. Even the math forums ignore me. I am needing to do an 'edgesurf' manually but I cant figure out the math involved, if anybody out there is capable of explaining it in simple terms to me, I'd be very very grateful, I cant figure this out. Thanks! Quote Link to comment Share on other sites More sharing options...
ReMark Posted February 11, 2009 Share Posted February 11, 2009 Google the following just as it is typed: "coons patch"+"how to calculate" When the results come up click on the link entitled: Topology Abstraction of Surface Models for Three-Dimensional Grid Generation written by Y.Zheng, N.P.Weatherill and O.Hassan. It's a PDF file about 11 pages long. Go to page 5 and start reading. Quote Link to comment Share on other sites More sharing options...
ReMark Posted February 12, 2009 Share Posted February 12, 2009 Here is another source of information about Coons Surfaces. It is an iPaper entitled Curves & Surfaces for Computer Graphics written by David Saloman of the Department of Computer Science at California State University. If you use the search feature in the upper right corner of the iPaper and type in coons it will take you to page 93, section 3.6.2, heading Four Curves. Coons Surfaces are covered here. Note that at the beginning of the iPaper the author lists numerous Internet sources for further information for curves and surfaces. The link to this iPaper is: http://www.scribd.com/doc/7075120/Curves-and-Surfaces-for-Computer-Graphics Quote Link to comment Share on other sites More sharing options...
Bella_Ciolla Posted February 12, 2009 Author Share Posted February 12, 2009 Wow thats so much for the references guys, this really helps out alot! I will read them this weekend, thanks again! Quote Link to comment Share on other sites More sharing options...
ReMark Posted February 13, 2009 Share Posted February 13, 2009 You're entirely welcomed, Bella_Ciolla. I hope you find the information of some value. Quote Link to comment Share on other sites More sharing options...
Bella_Ciolla Posted February 14, 2009 Author Share Posted February 14, 2009 I read through it today for a couple hours, for the most part it makes sense, but I get lost in the math a little though. But I have found the fundamental formula of it where it looks like you add two lofts together in the x and y direction than subtract something, but I am not sure exactly what your subtracting. I do, but I cant make sense of the math. Quote Link to comment Share on other sites More sharing options...
ReMark Posted February 14, 2009 Share Posted February 14, 2009 I read through it today...but I cant make sense of the math. I can barely balance my checkbook. I leave higher-order math to the professionals. Quote Link to comment Share on other sites More sharing options...
Bella_Ciolla Posted February 14, 2009 Author Share Posted February 14, 2009 Lol yeah I hear you. Either way you totally helped me out alot with those links so I appreciate it. I think I have enough information to do what I need to do, I will just leave the higher order math to the professionals as well, and spare myself the headache lol. Thanks again ReMark! Happy Vday too. Quote Link to comment Share on other sites More sharing options...
jatin1990 Posted August 13, 2009 Share Posted August 13, 2009 hi i want to how i can subtract any object from the object created using edgesurf command in 3d plan? when i try to do it it show the basic object is not region. please help me on that topic. Quote Link to comment Share on other sites More sharing options...
ReMark Posted August 13, 2009 Share Posted August 13, 2009 What type of object is being subtracted from the object that was created using the edgesurf command? Quote Link to comment Share on other sites More sharing options...
ReMark Posted August 13, 2009 Share Posted August 13, 2009 It is my opinion that the object created using edgesurf should have been turned into a region first then converted to a surface. Then you could subtract the second object (a solid?) from it. I don't recall if there is a convert to surface command in AutoCAD 2004. I would have to look that up. Quote Link to comment Share on other sites More sharing options...
ReMark Posted August 13, 2009 Share Posted August 13, 2009 I was unable to find such a command in 2004. However, there is a convtosurface command in 2009. Quote Link to comment Share on other sites More sharing options...
jatin1990 Posted August 13, 2009 Share Posted August 13, 2009 What type of object is being subtracted from the object that was created using the edgesurf command? Actually i am creating bonnet of car which is made in 3d by using edgesurf command and now i am want to create holes in front end of bonnet for the accomodation of headlights. So how can i create hole in bonnet created by edgesurf command? Quote Link to comment Share on other sites More sharing options...
ReMark Posted August 13, 2009 Share Posted August 13, 2009 At the moment, I cannot think of a way to do it using 2004. Doesn't edgesurf create a polygon mesh? As far as I can remember you cannot use Boolean operations such as union, subtract, interfere, etc. on anything by solids and surfaces. There might be some third-party software that will convert a mesh to a solid. I'm not sure. Quote Link to comment Share on other sites More sharing options...
ReMark Posted August 13, 2009 Share Posted August 13, 2009 Mesh to Solid for AutoCAD http://www.sharewareconnection.com/mesh-to-solid-for-autocad.htm Quote Link to comment Share on other sites More sharing options...
ReMark Posted August 13, 2009 Share Posted August 13, 2009 Another option is the mesh-to-solid lisp routine mentioned in this discussion. There is a link to download the lisp routine (m2s2007.lsp) contained in one of the posts. Give it a try. Please let me know if it helped or not. http://discussion.autodesk.com/forums/thread.jspa?threadID=469691 Quote Link to comment Share on other sites More sharing options...
ReMark Posted August 13, 2009 Share Posted August 13, 2009 I just remembered that there is a mesh-to-solid lisp routine here at CADTutor in the AutoLisp Archive forum (m2s.lsp). Probably a version of the one mentioned above. Quote Link to comment Share on other sites More sharing options...
jatin1990 Posted August 14, 2009 Share Posted August 14, 2009 Actually i am using 2006 version not 2004 and please update it in my profile. And i will check today all information u gave me and then i will update u about result. i just check now convtosurface surface command is not working in 2006. Quote Link to comment Share on other sites More sharing options...
jatin1990 Posted August 14, 2009 Share Posted August 14, 2009 Another option is the mesh-to-solid lisp routine mentioned in this discussion. There is a link to download the lisp routine (m2s2007.lsp) contained in one of the posts. Give it a try. Please let me know if it helped or not. i downloaded m2s2007.lsp file from ur given link but now i want to know how to install it into my autocad2006 version. please help me. Quote Link to comment Share on other sites More sharing options...
ReMark Posted August 14, 2009 Share Posted August 14, 2009 Forum members are responsible for their own profiles. Update yours by clicking on User CP (top of screen) and selecting, from the column on the left, Edit Profile. You have downloaded a LISP file. LISP is a programming language. Lisp routines are not installed they are loaded. To learn how to load a lisp routine visit the CADTutor AutoCAD FAQ section of this website (see top of page). The category you are looking for is titled Customisation. Please read the article How do I use an AutoLISP routine? That explains everything. If you have further questions just ask. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.