Nicolas Gauvin (nicolas++at++cae.ca)
Sun, 25 Feb 1996 19:52:50 -0500
> I have been trying to change the near clipping plane (using pfGetChanView())
> but within the current DRAW process and I wish it to take effect for the
> current frame. The scenegraph is quite simple. Using the above
> function and pfChanView() seems to have no effect until the next frame.
> Is there any way to make the change occur for this frame? Bypassing
> Performer and using straight gl is an option, but would make some other
> things more difficult (since I wish the new near clipping plane to
> be effective for all nodes in the scene graph).
I ran into this exact same problem a few weeks ago. Like you said, a solution
is to use a GL function like 'perspective' that allows you to set a new near and
far planes. However I found this to be a bit inconvenient to use
so I used a pfFrustum instead to set temporarely a new near and far plane
in my draw process. pfApplyFrustum will apply the changes immediatly to
the graphic card. If you want the new near and far values to affect Performer
processing like culling as well then trying to change them in
the DRAW is somewhat too late. Changing them using regular channel functions in the APP would be a better place.
If you want your changes to affect all renderings (include Performer's)
I believe you could set the changes in a draw callback before calling pfDraw.
___/ | ___/ Nicolas Gauvin e-mail: nicolas++at++cae.ca
/ / | / Software Developper voice: (514) 341-2000 x2275
/ / | __/ CAE Electronics Ltd. fax: (514) 340-5496
/ ___ | / 8585 Cote De Liesse, P.O. Box 1800
_____/ _/ _| _____/ Saint-Laurent, Quebec, Canada, H4L-4X4
This archive was generated by hypermail 2.0b2 on Mon Aug 10 1998 - 17:52:27 PDT