On 1/26/07, <b class="gmail_sendername">Arne Schmitz</b> <<a href="mailto:arne.schmitz@gmx.net">arne.schmitz@gmx.net</a>> wrote:<div><span class="gmail_quote"></span><blockquote class="gmail_quote" style="border-left: 1px solid rgb(204, 204, 204); margin: 0pt 0pt 0pt 0.8ex; padding-left: 1ex;">
Am Freitag, 26. Januar 2007 15:03 schrieb Carsten Wartmann:<br>> Arne Schmitz wrote:<br>> > Am Freitag, 26. Januar 2007 04:40 schrieb ZanQdo:<br>> >> Hi, I love this feature of XSI subdivition, made a gif about it:
<br>> >><br>> >> <a href="http://dogfight.3developer.com/SubTris2Tris.gif">http://dogfight.3developer.com/SubTris2Tris.gif</a><br>> >><br>> >> it subdivides triangles to triangles instead of making quads and keeps a
<br>> >> very smooth shape, could this be done with blender?<br>> ><br>> > Can you elaborate on that? Do you mean that instead of Catmull-Clark<br>> > Subdivision, blender should also offer Loop-Subdivision?
<br>><br>> Did you notice the image was a animated gif?<br><br>No, I did not. :) But now I have seen it.<br><br>> With that xsi option it was subdividing into tris along the last<br>> edgeloop. However I am not sure why it should be smoother then (at least
<br>> not on a sphere?)<br><br>Ah yes, the problem with CC on triangle surfaces is, that it generates bad<br>meshes with irregular vertices in the first iteration. Also the irregular<br>vertices will be kept after more iterations. CC and Loop subdivision have
<br>both the property of being C^2 on all regular vertices, so for smoothness we<br>want to avoid irregular vertices. There was a paper on this topic, that shows<br>how to combine CC and Loop and how to join them in a C^2 manner:
<br><br><a href="http://portal.acm.org/citation.cfm?id=1037957.1037959&coll=GUIDE&dl=GUIDE&CFID=740782&CFTOKEN=25050312">http://portal.acm.org/citation.cfm?id=1037957.1037959&coll=GUIDE&dl=GUIDE&CFID=740782&CFTOKEN=25050312
</a><br><br>HTH,<br><br>Arne<br></blockquote></div><br>Hi, folks. I also found this paper here in case you don't have an ACM account:<br><br><a href="http://www.cs.rice.edu/~jwarren/papers/triquad.pdf">http://www.cs.rice.edu/~jwarren/papers/triquad.pdf
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