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Subject: -26- Transparency
Date: 8 Apr 1994 00:00:01 EST
pfTransparency works only on machines that support either
blendfunction or multisampling.
Sometimes users report that their transparency seems quantized. This
is not a bug -- Performer defaults to using Multisample transparency
(msalpha) when multisampling is enabled, instead of using the
"standard" (blendfunction) transparency mechanism.
Multisample transparency is faster but has much less resolution, and
so less quality. Standard transparency using blendfunction is
slower, but the quality is very good.
To force Performer to use higher-quality (but slower) transparency
when multisampling,
1.0/1.1: pfGStateMode (gstate, PFSTATE_TRANSPARENCY, 2);
1.2: pfGStateMode (gstate, PFSTATE_TRANSPARENCY, PFTR_HIGH_QUALITY);
aka PFTR_BLEND_ALPHA
In 1.0/1.1 the BLEND_ALPHA token was not exposed, but just use '2'.
Be sure to revisit this code when you port to 1.2, as the token has
changed.
See the pfTransparency(3pf) man page for more details.
Up: SGI performer Frequently Asked Questions (FAQ)
Next: -27- Frame control on low- and mid-range machines
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