Re: Stencil question

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Joaquin Casillas Melendez (jcasilla++at++glup.eleinf.uv.es)
Fri, 30 May 1997 10:52:02 +0100 (WETDST)

On Thu, 29 May 1997, Nicolas Gauvin wrote:

> On May 29, 6:30pm, Joaquin Casillas Melendez wrote:
> > Subject: Stencil question
> > Hi all!
> > I am trying to draw an objet over a given plane, and I don't want the
> > object to be drawn outside the limits of the plane. In opengl this can be
> > achieved by drawing the plane (floor) and at the same time writing a
> > certain value to the stencil buffer. Then, in the draw routine, the
> > object will be drawn only over the pixels with that a certain value.
> >
> > I don't know the way to do this in Performer, so any help would be
> > appreciated.
> >
>
> You can use a pfLayer node for this with mode PFDECAL_BASE_STENCIL.
> The first child of a pfLayer is drawn first and acts as the base.
> It sets the stencil based on the depth test result. The other children
> are drawn right after and appears only where the stencil is 1.
>
   
  Hello Performers.
  I have already used a pfLayer whith stencil mode, and the decal children
is correctly drawn only over the base children, so all works fine.
However, every time the viewpoint is moved or the window resized, the
decal node begins drawing incorrectly outside the base geometry. I am
using perfly code to try this but I don't know if something is overriding
the stencil value. Any suggestion about what's going wrong?

Thank you again.

> --
> Nicolas Gauvin CAE Electronics Ltd., 8585 Cote De Liesse
> 3D Graphics Software Saint-Laurent, Quebec, Canada, H4L-4X4
> nicolas++at++cae.ca Tel: (514) 341-2000 x2275, Fax: (514) 340-5496
>

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_/ Joaquin Casillas Melendez | email: jcasilla++at++glup.eleinf.uv.es _/
_/ ARTEC (LISITT) | _/
_/ Dept. Electr. & Informatics | Phone: +34 6 360 4484 Fax: +34 6 361 6198 _/
_/ University of Valencia | Address: Hugo de Moncada 4. 46010 Val.(SPAIN)_/
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