Whoops - forgot to include the numbers referencing the original email. Added them below.
Matthew W. Fuesz Software Engineer Asc. Lockheed Martin STS 1210 Massillon Road Akron, OH 44315 [EMAIL PROTECTED] ________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Fuesz, Matthew Sent: Monday, August 04, 2008 12:31 PM To: OpenSceneGraph Users Subject: Re: [osg-users] Viewer/CompositeViewer 1 - Slaves can be moved independently of the main camera by setting their reference frames to ABSOLUTE_RF. Otherwise, yes, they are offset from the main camera. 2 - Yes, slaves can either share the main graph or may have their own subgraphs. 3 - Typically, yes, though this all depends on what they're being used for. I have used a slave to provide an orthographic overlay (HUD) projection, which has its own unique subgraph. A single Viewer should be used when there is a single conceptual view, while CompositeViewer should be used when there is more than one. See the Viewer vs. Composite viewer programming guide on the OSG site for more discussion on this (including usage examples). Matthew W. Fuesz Software Engineer Asc. Lockheed Martin STS 1210 Massillon Road Akron, OH 44315 [EMAIL PROTECTED] ________________________________ From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of [EMAIL PROTECTED] Sent: Monday, August 04, 2008 12:21 PM To: osg-users@lists.openscenegraph.org Subject: [osg-users] Viewer/CompositeViewer I'm starting to convert several apps from OSG 1.X to the current release. I've read the posts regarding Viewer and CompositeViewer and want to make sure I'm understanding it right. If you don't mind a few beginner questions... 1) Viewer (which "is a" View) can have one or more Cameras, but if using multiple Cameras, they are positionally slaved to the single View Camera by offset matrices, right? 2) The slaved Cameras can share the subgraph (Scene) below the View Camera, but if desired, they could have their own subgraphs? 3) It seems that generally, since the slaves are offset from the View master camera, for most applications, they would share the same Scene, right? 4) CompositeViewer (which "contains" Views) can be more flexible since each View Camera can be independently positioned (i.e., different views of the same Scene, but where Camera 2 doesn't necessarily follow Camera 1). 5) The View(s) within a CompositeViewer could themselves be single-Camera or master-slave configurations. 6) It seems that a CompositeViewer with a few Views could be functionally equivalent to a "Viewer with slave Cameras" provided the user positions the CompositeViewer Views with respect to a designated "master" View in real-time? 7) I see some efficiencies, such as a master-slave View applying the Update traversal only once to the shared Scene. Are there any other significant benefits (e.g., cull, rendering, state) that make a Viewer master-slave setup more efficient than the equivalent manually-slaved Views in a CompositeViewer? Sorry for the length, but I hope this post might be useful to others just starting the 1.X to 2.X conversion. Thanks! Dan Guinther ________________________________ Looking for a car that's sporty, fun and fits in your budget? Read reviews on AOL Autos <http://autos.aol.com/cars-BMW-128-2008/expert-review?ncid=aolaut0005000 0000017> .
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