Hi, Performers:

Last week I sent an e-mail asking for help about how to use the stencil buffer
with Performer 2.0. Till the moment I havenīt received any suggestions, but
I am quite sure that somebody must have dealt with this problem before.

I am using Performer 2.0 with an Indigo2 High IMPACT with 4 TRAM. This
machine has Open/GL native graphics hardware.

I need to create a sort of binocular with a graduated grid, to look trough and see
the database terrain augmented. I have already solved putting the grid, using
the (unexisting in OpenGL) overlay plane , in a similar way as Performer does
with the stats channel. But I am still having series problems with the use of the
STENCIL buffer, so as to draw the shape o a black binocular.

I am using a Post-Draw Callback function, within the framework of PERFLY, and
I have achieved some results, but I am having a problem with the shape of the
binocular flickering between the desired black and an strange sort of clearScreen
apparently every frame. This problem misteriosly dissapear if I do a window
resize, or I do iconize the window and restore it the maximum size. But as soon
as I switch the binocular off, and on again, the problem of the flickering appears
again as well.

I would hugely appreciate if somebody could tell me where to find any source of
information about the use of the stencil buffer with Performer 2.0, or any fragment
of source C code making use of it.

Thanks in advance.

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Rafael Garcia
ELCO Sistemas
Simulation Division
Madrid - Spain
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