Re: [Mesa3d-users] Glu Nurbs Error when trimming a nurb surface

[Brian P. <bri...@tu...>]

n9ine nvidia engine wrote:
> Hi all;
> 
> I a m programming a nurb viewer using a 3d engine (written in c++). I
> am using glu api to create the nurb and then tissalate it.
> 
> I have got this error  when I try to trim the surface. The same code
> work fine when I use Opengl to draw the nurb. And I succeded to view a
> non trimmed surface with the engine. But when I trimm it :( this is
> What i got :
> 
> checkjarc: geometric linkage screwed up 3
>         PWLARC NP: 2 FL: 1
>                 VERTEX 0.250000 0.500000
>                 VERTEX 0.000000 0.000000
>         PWLARC NP: 2 FL: 1
>                 VERTEX 0.250000 0.250000
>                 VERTEX 0.000000 0.000000
> Assertion failed: bin.firstarc()->check() != 0, file ..\..\..\..\src
> \glu\sgi\lib
> nurbs\internals\subdivider.cc, line 658
> 
> Can some gentil man help me.
> 

The nurbs tessellator/trimmer is fairly complex code so it's hard to say 
what's really happening.  A few things you could try though:

1. It looks like there's some debug code in the Arc::check() function in 
arc.cc that, if enabled, might give some clues.

2. Try disabling the failing assertion, or just return from the function 
if it fails.

-Brian