Help save net neutrality! Learn more.
Close

Strange error

Discussion
2005-03-14
2013-04-05
  • Frédéric PRACA

    On my current work in progress, I get this error message :"nct_getorientation: Error! Could not determine 3 different points!"
    What is it ?
    I also think that this is the reason why this model crashes Ayam on FreeBSD 5.3 (despite the fact that it works under win32 and Linux).

     
    • Randolf Schultz

      Randolf Schultz - 2005-03-14

      Hi Frdric,

      this error message is probably caused by a
      degenerated NURBS curve. Ayam tries to calculate
      the orientation of the curve in order to adapt
      in e.g. an automatic trim curve generation but
      fails to do so for your curve.
      Do you care to share your model so that I can
      have a look at it?

      best regards,
      Randolf,
      --
      http://www.ayam3d.org/    Reconstruct the World!

       
    • Frédéric PRACA

      Let's go share it !!
      You'll find it there (http://frederic.praca.free.fr/3D/chevalAqsis.ay  for the aqsis version and http://frederic.praca.free.fr/3D/cheval2.ay for the BMRT version).

      Regards,
      Fred

       
    • Randolf Schultz

      Randolf Schultz - 2005-03-14

      Aha, thanks for that nice model. I do hope you
      share the finished version with us!
      The culprit lies in the "barre" object; it has
      a much too big bevel radius, reduce this to
      about 0.1. Other objects also have too big bevel
      radii, e.g. the head of the horse. I had to
      decrease it to "0.00625" to get cap surfaces!
      Please be careful with caps and bevels, the
      underlying algorithms are not bullet proof (yet),
      and if strange surfaces result, Mesa may crash.
      I could actually reproduce crashes with your
      model, but they all lead to Mesa/SGI-GLU.

      best regards,
      Randolf,
      --
      http://www.ayam3d.org/    Reconstruct the World!

       
    • Frédéric PRACA

      Don't worry, I'll share it !
      The "barre" object (the stick). The bevel radius is equal to the radius of the ICurve because I wanted it to look like a kind of cigar. Reducing this to 0.1 makes it a beveled cylinder (which it is in fact). The other way is to do a concatenation of two quarter and a straight line and then to revolve it. But I found the strong beveled cylinder easier.
      For the horse head, I don't really understand even if I've noted what you said. Such design was wanted because extusion was easier than any other design.
      Did you notice the artifacts at both ends of what I called "bascule" ? Any idea about that ? I personnally think that this is a problem with my Concat object and the fillet option. What do you think about it ?

      Fred

       
    • Randolf Schultz

      Randolf Schultz - 2005-03-15

      About the barre: You are right. But apart from
      the bevel you requested caps from a curve which
      is (due to the bevel radius) degenerated to one
      single point in space (minus floating point
      roundoff errors, which is why it seems to work
      on some platforms)! So either switch off the caps
      or decrease the bevel radius.
      The horse head does not work right because of
      the way the ICurve represents the starting point
      of the internal NURBS curve. You can see the
      error easily by converting the ICurve to a NCurve
      "in place" and then zoom to the starting point.
      The bevel intersects itself!
      To get around this, just move the starting point
      of your ICurve away from the corner to about the
      middle of the lower straight part of the curve.
      You will need to insert new points and delete
      and move some other points to do this.
      Check the bevel for self intersections!

      best regards,
      Randolf,
      --
      http://www.ayam3d.org/    Reconstruct the World!

       
    • Frédéric PRACA

      Thanks, it seems to work correctly now, even if I still have some artifacts on the "bascule" objects.

       
    • Randolf Schultz

      Randolf Schultz - 2005-03-15

      The bascules concat curves with weights (the
      half circles) with other curves, which does not
      work well. I suggest to do the following:
      Reset the weights of the half-circles (<W>), switch
      their Knot-Type to "NURB", move the control points
      so that the transitions to the long curves
      are smooth and the "half-circle" is circular
      again (requires some tweaking); finally, switch
      ConcatNC Knot-Type to "Custom".

      best regards,
      Randolf,
      --
      http://www.ayam3d.org/    Reconstruct the World!

       
    • Frédéric PRACA

      No more artifacts, thanks Randolf !

       

Log in to post a comment.