sintef-geometry/sisl

The SINTEF Spline Library

sisl's Issues

Can't build viewer

It seems like the viewer and streaming directories got left behind in the cmake upgrade. The User manual says to go to those directories and type "make viewer" and "make lib" respectively. Obviously that doesn't work with cmake.
There are makefiles, but they just include "makefile_template" which doesn't exist anywhere in the source as far as I can tell.

Clarication on surface cration

Hello,
I've a problem using the library.
This the problem.
I have 2 couples of curves: 2 straight lines, and 2 arcs. I created 4 different sislcurves object and then tried to create a surface.
Here is the problem: how can I create an extruded surface or a ruled surface? The s1538 function create a surface different from a right extrusion that not respect the four boundary curves.
Is there also a book or a reference to connect coded function with standard geometric theory?

Thanks in advance

error: values.h: No such file or directory

in sislp.h ，There is an error here. How can I solve him?
my computer win 10，QT 5。

Dereferring nullpointer in s1251

In s1251 here, s1710 is called. the return value jstat can be 5:

parameter value at end of
curve, rcnew1=SISL_NULL or
rcnew2=SISL_NULL.

indicating that qc1 OR qc2 may be NULL. This is not handled by s1251, leading to a nullptr exception here or here in our case.

Our analysis is that in this case we are approaching the resolution limit, but the check for this in s1251 is slightly different from that in s1710. It might be solved by checking for NULL and stop recursion.

where is the inlude file "GoReadWrite.h" in the example file

how to approximate a circle by s1356

we have 6 points want to approximate a circle by s1356 .
But seems get a b-spline curve not NURBS curve.
How can i to approximate NURBS curve?
I don't know how to set the weights for approximating a circle.

Clarification of licensing

1. On the SINTEF project page (http://www.sintef.no/projectweb/geometry-toolkits) it is stated that the library is available under the GPL for non-commercial use, but I can see no such statement in this git repository.
2. I would like to use the library to help support my project libIGES (https://github.com/cbernardo/libIGES) which I hope will eventually be included in the KiCad EDA package (http://www.kicad-pcb.org). Although KiCad is free software it is used by many companies for commercial purposes. Would the use of SISL in KiCad be a violation of the intention of the SINTEF licensing or would this be acceptable?

display surface

get the the point X,Y,Z when give a surface;
when i use void s1421(surf,der,parvalue,leftknot1,leftknot2,derive,normal,stat); i do not to know set parvalue value;

Calculating area of surface

First a big thanks is in order for a great library.

My question is, is there any command to calculate the area of a surface? If not, is there any other way of doing it?

Thanks.

Spline interpolation using a set of points

Hello,

I was trying to create a spline by interpolating a set of points and I used the function s1356. I am getting a curve with same number of points as my input. Plotting that data obtained doesn't seem to provide me any spline. Can someone please help me with this?

Get wrong sequence of intersection points by s1850

how to create a arc with a start point and and end point with radius of R.

Wrong component representation

in SISL_4.7_manual

Chapter 2.6 B-spline Surfaces the 2nd n{1} should be n{2} instead

get the the point X,Y,Z when give a arc length.

Can provide a function that to get the position (x , y , z) of a specially length arc from a spline curve.
Ex: give the arc AB , the length is 150 from start A. i want to get X,Y,Z of point B when the curve is 3D curve.

How to rotate a curve ?

How can I rotate a curve ?

Approximate a sphere (rational surface) as a B-spline (non-rational) surface

I have tried to approximate a sphere with a B-spline surface using the s1365 function as indicated in the manual.

In one parametric direction it seems to work properly, but not in the other. Any suggestions? Thank you.

///////////////
center[ 0 ] = center[ 1 ] = center[ 2 ] = 0.0;
axis[ 0 ] = 0.0; axis[ 1 ] = 0.0; axis[ 2 ] = 1.0;
equator[ 0 ] = 0.0; equator[ 1 ] = 10.0; equator[ 2 ] = 0.0;
_GetSISL( )->s1023( center, axis, equator, 2, 4, &surface2, &stat );
if ( stat < 0 ) return false;
_GetSISL( )->freeSurf( Surface );
Surface = surface2;

	_GetSISL( )->s1365( Surface, 0.0, 0.01, 0.0, Surface->idim, &surface2, &stat );
	if ( stat < 0 ) return false;
	_GetSISL( )->freeSurf( Surface );
	Surface = surface2;

//////////////

How to save a SISLCurve information to a TXT file, and read it from txt by other app

After computing a SISLCurve, how to save it's information to TXT file and use in other app?

Failed to create closed surfaces :(

No routine to construct closed surfaces + Using other routines fails when collapsing on a single point :(

Documentation not clear about using s1506

I am trying to use s1506 to compute position, first and second derivatives of a NURBS surface. I have a hard time understanding what is in the eder array output when ider > 0. I have a 2d NURBS in a 3d space. When ider = 0 I am getting three entries per point, which are the coordinates (position) of the NURBS surface. When ider = 1 there are 9 entries per point. The first three are the same as when ider=0. The documentation states that in this case (ider = 1) "position and first derivative" (! note the singular, I think this should be plural "derivatives") are calculated. In my case there should be just two first order derivatives. I can identify eder[3] and eder[7] as the total span in u- and v-directions, but the other entries are unclear. Are eder[5] and eder[8] the first order derivatives? Their values don't look right in my case. Things get even more confusing when ider=2. I am getting 18 entries per point. the first nine are the same as when ider = 1. What are the other 9?
I think the documentation needs to be a little more specific about this. An annotated example would be great.

how to draw the curve into a file.

The error of approximating a circle by s1356

I have some points want to approximate a circle by s1356 .
but when I debug , program crash with the error : Error status : -101 Call from routine : s1912 Position : 0 ,Scene radius must be positive - Ignoring value.
When I approximate a circle with 100 points that x = i , y= i * i , z=0 (i=1,2,3...100), I can get the result.
But if I change the points to x=i/100,y= i * i / 10000,z=0.,the program crash.
My real data is 3D point such as (0.0580612 0.494216 -0.163759) and the distance with next point is less than 0.0001.
I don't know the reason of the error.

Triangulation

I would like to know if, SISL provides any sort of mechanism for surface triangulation?

Potential out-of-bounds access in s1323

GCC 8.3 warns that

warning: iteration 3 invokes undefined behavior [-Waggressive-loop-optimizations]

here s1323.c:205:12:

Indeed, its seems that here:

• kstop==16
• kdimp2==5

which means that the loop

  for (ki=0,kl=0 ; ki<kstop ; kl++,ki+=kdimp2)
    {
      temp = sdirec[kl];
      carray[ki] = (double)1.0 - temp*temp/tcost2;
    } 

iterates 4 times (0, 5, 10, 15) and kl takes the values 0, 1, 2, 3. 3 is out of bounds.

Fails to build shared library on WIndows/MSVC

While building with MSVC (9.0) and -DBUILD_SHARED_LIBS:BOOL=TRUE, compilation fails because no import library is generated during the build.

To reproduce, open the "Command Shell" provided with the toolchain and run

cmake -DBUILD_SHARED_LIBS:BOOL=TRUE
nmake

Full log at http://ci.kicad-pcb.org/job/windows-sisl-msvc/cpu=x86,label=windows/10/console

planar NURBS curve with weights <> 1.0 not evaluating in plane

Hi,

I'm having serious difficulty understanding what is happening with a curve that has weights that are not 1.0. This code for generating a circle:

` double coeffs[ 36 ] = {
0.0, -radius, 0.1, 1.0,
-radius, -radius, 0.1, 0.707,
-radius, 0.0, 0.1, 1.0,
-radius, radius, 0.1, 0.707,
0.0, radius, 0.1, 1.0,
radius, radius, 0.1, 0.707,
radius, 0.0, 0.1, 1.0,
radius, -radius, 0.1, 0.707,
0.0, -radius, 0.1, 1.0
};
double knots[ 12 ] = {
0,
0,
0,
0.25,
0.25,
0.5,
0.5,
0.75,
0.75,
1,
1,
1
};

SISLCurve * curve = newCurve( 9, 3, knots, coeffs, 2, 3, 1 );`

produces this curve:

which is obviously not planar. tracing the code to s6ratder.c:161, it says:
gder[ki] = eder[ki] / w0;

which seems to suggest the position is divided by the weight, which results in coordinates that are not in the xy plane.

could anyone shed some light on this ?

thank you !

Jonathan