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

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mesa3d-users

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

From: n9ine n. e. <n9i...@gm...> - 2008-09-01 12:49:43

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.
kind regards

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

From: Brian P. <bri...@tu...> - 2008-09-01 14:31:00

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

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

From: n9ine n. e. <n9i...@gm...> - 2008-09-02 07:13:19

Hi Brian,
Thank you for help, I have done what you have suggested.
I obtianed this error :

s difference 0.250000
Assertion failed: head == NULL, file
..\..\..\..\src\glu\sgi\libnurbs\internals\
bin.cc, line 58

I disabled this last assertion, I obtained this one


Run-Time Check Failure #0 - The value of ESP was not properly saved across a
function call.  This is usually a result of calling a function declared with
one calling convention with a function pointer declared with a different
calling convention.


//file : nurbstess.cc - line 308
    do_freeall( );
    resetObjects();
}


I think it could be precision error between the engine and glu (s difference
0.250000). I am using GLfloat to declare cltpoints and knots. Is this
possible?

Regards

[Mesa3d-users] tnl/t_draw.c:205: bind_inputs: Assertion `inputs[i]->BufferObj->Pointer' failed.

From: Utkarsh A. <utk...@ki...> - 2008-09-03 15:22:00

Hi Brian,

I am trying to come up with a small test case that reproduces this issue 
that we are having with ParaView using Mesa 7.1 (as well as git-Mesa) on 
a 64 bit debian box.

The assertion fails following repeated creation/deletion of display 
lists (ofcourse when display lists are not used, everything is peachy).

For debugging purposes I put a printf as follows in tnl/t_draw.c:

static void bind_inputs( GLcontext *ctx,
			 const struct gl_client_array *inputs[],
			 GLint count,
			 struct gl_buffer_object **bo,
			 GLuint *nr_bo )
{
    ...
    for (i = 0; i < VERT_ATTRIB_MAX; i++) {
       const void *ptr;

       if (inputs[i]->BufferObj->Name) {
	 if (!inputs[i]->BufferObj->Pointer) {
	    ...
	
	    printf("i : %i\n", i);
	    printf("name: %i\n", inputs[i]->BufferObj->Name);
	    assert(inputs[i]->BufferObj->Pointer);
	 }
    ...
}

On successful runs it looks like:
i : 0
name: 1
i : 0
name: 1
i : 31
name: 1

However when the assertion fails, the output is:
i : 0
name: 1
i : 31
name: 10999

Not sure that's very helpful, perhaps you can point me in the right 
direction for producing more relevant debug output.

Thanks,
Utkarsh