Nebula3的渲染流程

<?xml version="1.0" encoding="UTF-8"?>
<Nebula3 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../../../schemas/frame.xsd">

<!-- 
    Test frame shader for the Win32 platform.
    Renders a dedicated depth pass first, then renders the solid and alpha geometry to a (possibly
    multisampled) color buffer, and finally resolves the result through a post-effect into the backbuffer.
--> 
<FrameShader name="DX9Default">
    
    <!-- declare render targets -->
    <DeclareRenderTarget name="ColorBuffer" format="A8R8G8B8" depth="true" relWidth="1.0" relHeight="1.0" msaa="true"/>
    
    <!-- render the world to the BackBuffer render target -->
    <Pass name="Color" renderTarget="ColorBuffer" shader="p_color" clearColor="0.2,0.2,0.2,1.0" clearDepth="1.0" clearStencil="0">
        <Batch shader="b_depth" type="Depth" shdFeatures="Depth" nodeFilter="Solid" sorting="FrontToBack" lighting="None"/>
        <Batch shader="b_solid" type="Solid" shdFeatures="Solid" nodeFilter="Solid" sorting="None" lighting="SinglePass"/>
        <Batch shader="b_alpha" type="Alpha" shdFeatures="Alpha" nodeFilter="Alpha" sorting="None" lighting="None"/>
    </Pass>

    <!-- apply a post effect with color correction, renders directly to the presentation buffer -->
    <PostEffect name="Compose" shader="pe_compose">
        <ApplyShaderVariable sem="ColorBuffer" value="ColorBuffer"/>
        
        <!-- render debug stuff on top of complete frame -->
        <Batch shader="b_shape" type="Shapes"/>
        <Batch shader="b_empty" type="Text"/>
    </PostEffect>
    
</FrameShader>
</Nebula3>