root/OpenSceneGraph-TrainingMaterials/trunk/Presentations/PortingToOpenSceneGraph/PerformerToOSG.p3d @ 10195

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<name>Siggraph Menu</name>
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<env>DATA_DIR=../../Data</env>

<path>${DATA_DIR}</path>
<path>${DATA_DIR}/OpenSceneGraph-Data</path>
<path>${DATA_DIR}/Images</path>
<path>${DATA_DIR}/Models</path>
<path>${DATA_DIR}/Earth</path>

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<slide inherit="front">
<background>Images/default_blue.jpg</background>
<title> </title>
<layer>
<paragraph position="0.5 0.5 0" alignment="CENTER_CENTER" character_size="0.07">
Performer to OpenSceneGraph</paragraph>
<image position="0.5 0.90 0" scale="0.55">Images/logops.rgb</image>
</layer>
</slide>

<page inherit="middle" title="Similarities">

Scene Graph paradigm

Performance - Solid 60Hz

View Frustum Culling

State Sorting

Scalability :

    Multi-threaded 
    Multi-pipe
</page>

<page inherit="middle" title="Differences">
 
Standard C++

Design Patterns

Extensibility

Support for latest OpenGL vesions/extensions

Licensing - Can't beat Open Source!

Community - OSG 10 times as active

Prospects - OSG is going strong

Market share  - OSG now bigger than rest put together

</page>

<page inherit="middle" title="Nodes">
 
pfNode -> osg:::Node

pfGroup -> osg::Group

pfSCS -> osg::Transform

         DataVariance()==STATIC
                  
pfDCS -> osg::Transform

         DataVariance()==DYNAMIC

osg::Transform -> osg::MatrixTrasform
                  osg::PositionAttitudeTransform
                  osg::AutoTransform
                  osgSim::DOFTransform
</page>

<page inherit="middle" title="Nodes cont.">
 
pfSwitch -> osg::Switch

         -> osgSim::MultiSwitch         

pfLOD -> osg::LOD

pfClipMap -> no equivilant but...

      we have osg::PagedLOD
         
pfScene -> any osg::Node

</page>


<page inherit="middle" title="Geometry">
pfGeoSet -> osg::Geometry

OSG had alternatives:

    osg::Drawable base class
    osg::ShapeDrawable
</page>

<page inherit="middle" title="State">
pfGeoState can be attached to:

    - pfGeode
    - pfScene
    - hardwired
    
osg::StateAttribute
    - osg:Drawable
    - any osg::Node
    - inheritence top down
    - flexible
    - Native multi-texturing
    - native GLSL support
    - OpenGL modes decoupled
</page>

<page inherit="tetamiddle" title="State continued.">
osg::StateAttribute
    - Exensible state
    - Almost all OpenGL state
    
osg::State
    - tracks OpenGL state
    - per graphics context
</page>

<page inherit="middle" title="Traversals">
Performer
    - App
    - Cull
    - Draw
    - Isect
    
OpenSceneGraph

    - UpdateVisitor
    - EventVisitor
    - CullVisitor
    - DrawVisitor
    - IntersectVisitor   
    - PickVisitor 
</page>

<page inherit="middle" title="Threading">
Performer:

    - Multi-buffered
    - App - frame 1
    - Cull - frame 2
    - Draw - frame 3
    - 3 frame latency
    
OpenSceneGraph:

    - Single threaded Update - frame 1
    - Multi Cull-Draw pairs - frame 1
    - 1 frame latency
    
    - DatabasePaging    
</page>

<page inherit="middle" title="Application Framework">
Perfomer:
    
    - perfly (argggg!!!)

pfChannel -> Producer::Camera
          -> Producer::CameraGroup
          -> osg::CameraNode
          
pfPipe -> Producer::RenderSurface
       -> osg::GraphicsContext

</page>

<page inherit="middle" title="Performer to OpenSceneGraph">




Questions?

</page>

</presentation>