• Sergio

    Hi Randolf,

    Currently, working on any form with NURBS curves, i use allways the same number of points in all NURBS curves, even when it's visibly not necessary. As example, if a curve need 12 points, i set all others curves also with 12 points, even if most of them needs only 8 or 6 points. What do you mean about :

    - it's really necessary ?
    - has this fact a big importance for the machine (memory, processor charge, etc…) ?



  • Sergio,

    it is nowadays not necessary to use compatible curves for the sake of execution speed
    (and if there are lags, one can still switch to lazy notification). One other aspect that you
    should consider, however, is direct control over the output surface (in terms of width/height
    and knots), which you will lose when you input arbitrary curves. Direct control may be
    desirable, if you want to add texture coordinates via PV tags, or use a tesselation scheme
    that depends on those parameters, or want different surfaces in the scene to be compatible
    in this regard (e.g. to join them).

    kind regards,

  • Sergio

    Hi Randolf,

    OK. Thank's for this documented explanation. So i'm able to consider in each case what as method is the most adapted, assuming that compatible curves are normally the best way.



  • joe stump
    joe stump

    Hi, I am wondering what intersection algorithms you are using for NURBS. I looked at the source files in the NURBS folder and it appears that you are using some sort of Bezier clipping (correct me if I am wrong). I do not see any intersection code for NURBS surfaces - does Ayam3d do intersection on NURBS surfaces returning, say, intersection curves?


    p/s: I'm not sure if this is the right place to post this, since I think one is not allowed to post.

  • Greetings,

    the Ayam codebase currently does not contain any intersection
    algorithms, not even Bezier clipping. Your contribution is welcome.

    You can create new threads by scrolling down the forum view
    to the very bottom.


  • sean stein
    sean stein

    i'm currently looking into ayam and though i don't quite understand all the underlying concepts yet, getting the impression it has some nice features like parametric objects.
    like in the post before i'm missing a convenient way of trimming surfaces+curves by intersection or creating trim curves/curves on surfaces.
    is there any workaround e.g. booling closed surfaces or making the ends of trimmed/split splines meet?
    or just a different modeling approach, i'm corrupted by rhino and alias ways of doing things?
    my goal is to create models that are made of closed groups of surfaces or solids, for CAD usage.


  • Greetings,

    if you just want to render your models to images, you can use the booleans
    of Ayam. Otherwise you can try to decompose your objects in a way that the
    Ayam ConcatNP object can handle, e.g. chaining sub-surfaces to form new
    surfaces in hierarchical fashion can also get you far and you can then export
    the new geometries for further processing in CAD.
    What you do not get is: intersections and projections, rolling ball blends, all
    the approximative stuff. Ayam is more like relational geometry: