Width of gluNurbsCurve

[Esben Stien]

I'm trying to work with a NURBS modeler.

I want the splines to be thicker than the default, which is really hard
to look at, since they are so thin.

I've tried to use glLineWidth(), which makes it thicker, but comes with
a few problems. First of all, it draws the spline sort of like a strip,
not round and tubelike. Secondly, it doesn't look right, when you zoom
out; it gets big.

Also, I'm trying to have bigger control handles, but that also poses
problems, cause when you draw a sphere, f.ex, using normal GL commands,
it has specific dimensions. This doesn't work right, since it's supposed
to sort of scale with your zoom level.

It's a little hard to explain. Here's a picture I found of something
similar. On this image, the spline is a little thicker and the control
points are more visible than a simple vertex and they are also round.

http://www.solidsmack.com/wp-content/uploads/2009/10/solidworks-spline-axes.jpg

Any pointers as to how to achieve this?

--

[fungus]

On Dec 21, 12:27 pm, Esben Stien <b...@esben-stien.name> wrote:
>
> http://www.solidsmack.com/wp-content/uploads/2009/10/solidworks-splin...

>
> Any pointers as to how to achieve this?
>

That picture is just glLineWidth(). They've got antialiasing
enabled to make it look nicer but I bet it looks too thick
when you zoom out.

--
<\___/>
/ O O \
\_____/ FTB.

http://www.topaz3d.com/ - New 3D editor for real time simulation

[Esben Stien]

fungus <opengl...@artlum.com> writes:

> That picture is just glLineWidth(). They've got antialiasing enabled
> to make it look nicer but I bet it looks too thick when you zoom out.

Incorrect. Here's a video showing it; with zooming in and out:

http://esben-stien.name/share/boat_hull.avi

They are sort of like tubes. Also the control points and edit points
looks good in this video and something I'd like to recreate.

--

[fungus]

On Dec 21, 9:08 pm, Esben Stien <b...@esben-stien.name> wrote:

> fungus <openglMYSO...@artlum.com> writes:
> > That picture is just glLineWidth(). They've got antialiasing enabled
> > to make it look nicer but I bet it looks too thick when you zoom out.
>
> Incorrect. Here's a video showing it; with zooming in and out:
>

They don't zoom in and out very much so it's hard to
see exactly what they do.

> They are sort of like tubes.

I don't see any 'tube' effect, just lines.

> Also the control points and edit points
> looks good in this video and something I'd like to recreate.
>

Yes, they've done a lot of work to make it look nice.

The only way to get full control is to forget
gluNurbsCurve and glLineWidth and do all the math
yourself. Transform the endpoints of the lines and
draw a screen-aligned polygon strip (like billboards),
It's what I do in my 3D editor.