[vtkusers] transparent 3D over 2D

[Chris Volpe ARA/SED]

If depth peeling is something that's off by default, unless you explicitly enable it, then I'm not doing it. (In fact, I've never heard of it.) I just have 3D geometry with a color lookup table that varies the hue but keeps alpha constant at 0.5.


-Chris


> -----Original Message-----
> From: David Gobbi [mailto:david.gobbi at gmail.com]
> Sent: Friday, July 08, 2011 12:43 PM
> To: Chris Volpe ARA/SED
> Cc: vtkusers
> Subject: Re: [vtkusers] transparent 3D over 2D
> 
> Are you using depth peeling?  Depth peeling disables alpha, it is an
> alternate strategy to translucent rendering that doesn't use alpha and
> as far as I understand, it actually requires alpha-blending to turned
> off in order to work.
> 
> So I don't think that depth peeling can be used when an underlay is
> present (or at least, not in VTK).
> 
>  - David
> 
> 
> On Fri, Jul 8, 2011 at 10:32 AM, Chris Volpe ARA/SED <cvolpe at ara.com>
> wrote:
> > I'm rendering 3D geometry over a 2D image drawn onto the rendering
> window
> > using an Actor2D. The 3D geometry  is semi transparent, as can be
> seen when
> > some 3D geometry is drawn on top of other 3D geometry. However, the
> > transparency does not permit seeing the background image through the
> 3D
> > geometry. For purposes of the background image, the 3D geometry is
> > completely opaque. Is this an inherent limitation, or am I doing
> something
> > wrong?
> >
> >
> >
> > Thanks,
> >
> >
> >
> > Chris
> >
> > --
> > Christopher R. Volpe,
> > Ph.D.
> Email:
> > cvolpe at ara.com
> >
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> >
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