On Sat, Jun 30, 2012 at 12:13 AM, phoenix <[email protected]> wrote: > OK. I will post some pictures of the raytracing results from super > ellipsoids with e or n > 3. I also think generating multiple surfaces is a > way to get sharp corners, although it's a little bit more complicated than a > single surface.
Interesting images. Yeah, that's probably a multiple-surface situation - individual NURBS surfaces with "kinks" in them generally tend to cause problems, from what I can see... > I found it's really view dependent. That's quite strange. So, what is this > primitive usually used to do? IIRC, cline was used originally in some analytical situations - it's not a common primitive, and to the best of my knowledge we support it only for legacy analytical models and not for any modern stuff (certainly not for "normal" CSG modeling.) There are three options: 1. Document why it can't be expressed as a Brep and leave it at that. 2. Add a utility command to take a "cline" primitive and translate it into it's "closest match" pipe primitive. That would a) allow people who don't want the quirky cline behavior to get a pipe that behave more like what they want, and b) provide a route to a Brep through the pipe conversion routines. We eventually will want to be able to go from cline to implicit pipe anyway, so it addresses two issues at once. 3. Pick a particular interpretation of the cline inputs for NURBS creation and generate that Brep. Personally, I'd suggest option two as the most useful feature even though it's not directly NURBS related - then if you want brep to do something intelligent with a cline, you could have cline's brep routine call the cline->pipe routine first and then pipe->brep using the results. > As far as I'm concerned, that will be a great challenge for me. NURBS > intersection is another GSOC project and is marked as 'hard'. So I will read > the papers you offer in a few days, and find out whether I can manage to do > it. Sounds great! If, once you've read over the papers, you decide you want to have a go at it we'll need to identify the approach and the ordering for intermediate pieces to work on - there will be a few of them. If you opt not to tackle it don't worry - there's still plenty of other things to do. I mainly suggested this one because it's more or less the next logical continuation of the conversion - essentially, fully supporting the "comb" conversion to brep. Also, despite being hard (or maybe because of it ;-) it is a fun problem for folks who like this kind of thing. Cheers, CY ------------------------------------------------------------------------------ Live Security Virtual Conference Exclusive live event will cover all the ways today's security and threat landscape has changed and how IT managers can respond. Discussions will include endpoint security, mobile security and the latest in malware threats. http://www.accelacomm.com/jaw/sfrnl04242012/114/50122263/ _______________________________________________ BRL-CAD Developer mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/brlcad-devel
