Hi,

On Mon, 2003-10-27 at 11:22, Akos Balazs wrote:
> Hi guys,

> 
> On Mon, 27 Oct 2003, Gerrit Voss wrote:
> 
> > On Sat, 2003-10-25 at 01:56, Andreas Zieringer wrote:
> > > Akos Balazs wrote:
> > >
> > > > Hi guys,
> > > >
> > > > I have a VRML model that has some billboard-like objects (mainly trees 
> > > > but
> > > > some structures aswell) that should be partially-transparent, and the
> > > > transparency should be controlled by the alpha channel of their 
> > > > textures.
> > > >
> > > > The problem is that when I render the scene I get the diffusecolor 
> > > > (white)
> > > > of the objects where the texture is transparent, instead of the objects
> > > > being transparent in those parts. Of course if I set the transparency of
> > > > the object's material to 1, the object will be fully transparent, but
> > > > that's not what I want. I remember there was some discussion a while ago
> > > > about transparency in VRML but I don't remember the details... :)
> > > >
> > > > Please see the attachment for a minimalist example. Is this currently
> > > > possible with OpenSG, is it a missing feature, or is it a bug? :)
> > > >
> > > > I use Gerrit's experimental VRML loader.
> > > >
> > > > Thanks,
> > > >         Akos
> > >
> > > Hi Akos,
> > >
> > > looks like a bug in the loader if you add a Blend chunk to the material
> > > it looks fine.
> >
> > as SF is not really reliable ;-), it's not a bug it's a kind of feature,
> > at least it is intended to be this way right now, just add a little
> > transparency to your material and it works.
>
> I don't get it, what does SF have to do with the VRML loader? :)

;-))), not much really except that getting mails out if order makes
following the dicussion thread a little bit more difficult ;-)

> I've tried your suggestion of adding a little transparency but it didn't
> seem to matter whether I add 0.01 or 1.0, the full object became totally
> transparent... :( While this is not as bad as having white rectangles
> around the trees in the scene, it's not good enough for me. :)
> 
> I haven't got around to try Andreas's suggestion yet, but I'll have to do
> a bit of programming as my model is big so I'll have to traverse() the
> graph after loading and add the blendchunk to each material encountered
> (or possibly only to those which should be transparent, but I think this
> chunk can safely be added to all materials).
> 
> Although this blendchunk-trick smells like a hack to workaround problems
> in the OpenSG VRML loader, which is not very nice IMHO (any chance of
> fixing/changing this behaviour in the long run?) but I can live with it.
> :)

Hmm normally the transparency stuff should do, I'll check it with your
model. May take a second as I have to rebuild my loader first ;-))

gerrit




-------------------------------------------------------
This SF.net email is sponsored by: The SF.net Donation Program.
Do you like what SourceForge.net is doing for the Open
Source Community?  Make a contribution, and help us add new
features and functionality. Click here: http://sourceforge.net/donate/
_______________________________________________
Opensg-users mailing list
[email protected]
https://lists.sourceforge.net/lists/listinfo/opensg-users

Reply via email to