Introduction to my galaxy engine 4: Test on local light model

CGBeginner

Introduction to my galaxy engine 4: Test on local light model

<div id="cnblogs_post_body">今天按照shadow volumn阴影的检查方法对spot light和point light的灯光范围模型做了个测试。
测试图片如下：（蓝色为场景中的物体，黄色表示场景中受灯光影响的部分，绿色为灯光模型）







depth fail test 和 stencil test 是在GPU中执行的，首先渲染蓝色的盒子RenderScene，再渲染灯光模型CalRadium（disable write to depth buffer），最后再将模板值为1的部分添加上另一个颜色来突出受光照部分LitScene，代码如下：

<div class="cnblogs_code">  1 SamplerState g_samWrap  2 {  3     Filter = MIN_MAG_MIP_LINEAR;  4     AddressU = Wrap;  5     AddressV = Wrap;  6 };  7   8 SamplerState g_samClamp  9 { 10     Filter = MIN_MAG_MIP_LINEAR; 11     AddressU = Clamp; 12     AddressV = Clamp; 13 }; 14 15 DepthStencilState DisableDepth 16 { 17     DepthEnable = FALSE; 18     DepthWriteMask = ZERO; 19 }; 20 21 DepthStencilState EnableDepth 22 { 23     DepthEnable = TRUE; 24     DepthWriteMask = ALL; 25     DepthFunc = Less_Equal;//set to less equal since texture background is ini as 1.0 26 }; 27 28 BlendState NoBlending 29 { 30     AlphaToCoverageEnable = FALSE; 31     BlendEnable[0] = FALSE; 32 }; 33 34 BlendState AlphaBlendingOn 35 { 36     BlendEnable[0] = TRUE; 37     SrcBlend = SRC_ALPHA; 38     DestBlend = INV_SRC_ALPHA; 39 }; 40 41 BlendState AdditiveBlending 42 { 43     AlphaToCoverageEnable = FALSE; 44     BlendEnable[0] = TRUE; 45     SrcBlend = ONE; 46     DestBlend = ONE; 47     BlendOp = ADD; 48     SrcBlendAlpha = ZERO; 49     DestBlendAlpha = ZERO; 50     BlendOpAlpha = ADD; 51     RenderTargetWriteMask[0] = 0x0F; 52 }; 53 54 RasterizerState DisableCulling 55 { 56     //FillMode = WIREFRAME; 57     CullMode = NONE; 58 }; 59 60 RasterizerState EnableCulling 61 { 62     //FillMode = WIREFRAME; 63     CullMode = BACK; 64 }; 65 66 RasterizerState FrontCulling 67 { 68     //FillMode = WIREFRAME; 69     CullMode = FRONT; 70 }; 71 72 BlendState DisableFrameBuffer 73 { 74     BlendEnable[0] = FALSE; 75     RenderTargetWriteMask[0] = 0x0; 76 }; 77 78 BlendState EnableFrameBuffer 79 { 80     BlendEnable[0] = FALSE; 81     RenderTargetWriteMask[0] = 0x0F; 82 }; 83 84 DepthStencilState TwoSidedStencil 85 { 86     DepthEnable = true; 87     DepthWriteMask = ZERO;//Turn off writes to the depth-stencil buffer. 88     DepthFunc = Less; 89      90     // Setup stencil states 91     StencilEnable = true; 92     StencilReadMask = 0xFFFFFFFF; 93     StencilWriteMask = 0xFFFFFFFF; 94      95     BackFaceStencilFunc = Always;// how stencil data is compared against existing stencil data.Always pass the comparison. 96     BackFaceStencilDepthFail = Incr;// describes the stencil operation to perform when stencil testing passes and depth testing fails. 97     BackFaceStencilPass = Keep;// describes the stencil operation to perform when stencil testing and depth testing both pass. 98     BackFaceStencilFail = Keep;//describes the stencil operation to perform when stencil testing fails. 99     100     FrontFaceStencilFunc = Always;101     FrontFaceStencilDepthFail = Decr;102     FrontFaceStencilPass = Keep;103     FrontFaceStencilFail = Keep;104 };105 106 DepthStencilState RenderNonShadows107 {108     DepthEnable = true;109     DepthWriteMask = ZERO;110     DepthFunc = Less_Equal;111     112     StencilEnable = true;113     StencilReadMask = 0xFFFFFFFF;//read stencil buffer to check if lit or not114     StencilWriteMask = 0x0;115     116     FrontFaceStencilFunc = Less_Equal;//If the source data is greater (multipay light)or equal to the destination data, the comparison passes.117     FrontFaceStencilPass = Keep;//Keep the existing stencil data.118     FrontFaceStencilFail = Zero;//Set the stencil data to 0.119     120     BackFaceStencilFunc = Never;//Never pass the comparison.121     BackFaceStencilPass = Zero;122     BackFaceStencilFail = Zero;123 };124 125 Texture2D  g_ModelTexture;126 127 Texture2D  g_NormDepthTexture;128 Texture2D  g_DiffuseTexture;129 130 matrix World;131 matrix View;132 matrix Projection;133 134 float4 g_AmbientColor = float4(0.1f, 0.1f, 0.1f, 1.0f);135 float4 g_DirLightColor = float4(0.3f, 0.3f, 0.3f, 1.0f);136 float3 g_DirLightDir = float3(0.0f, 1.0f, -1.0f);137 float4 g_LocalLightColor;138 //---------------------------------------------------------------------------------------------------------------------------------139 struct VS_MODEL_INPUT140 {141     float4 Pos            : POSITION;         142     float2 Tex            : TEXCOORD0;     143     float3 Norm        : NORMAL;       144 };145 146 struct PS_MODEL_INPUT147 {148     float4 Pos            :SV_POSITION;   149     float2 Tex            : TEXCOORD0;     150     float3 Norm        : TEXCOORD1;    151 };152 153 struct PS_MODEL_OUTPUT154 {155     float4 NormDepth    : SV_Target0;156     float4 DiffuseColor    : SV_Target1;157 };158 //------------------------------------------------------------------------------------------------------------------------159 struct VS_QUAD_INPUT160 {161     float4 Pos            :POSITION;           162     float2 Tex            : TEXCOORD0;       163 };164 165 struct PS_SCENE_INPUT166 {167     float4 Pos            :SV_POSITION;   168     float2 Tex            : TEXCOORD0;     169 };170 171 struct PS_SCENE_OUTPUT172 {173     float4 Color        :SV_Target;   174     float     Depth        : SV_Depth;175 };176 //-----------------------------------------------------------render scene to gbuffer-----------------------------------------------177 PS_MODEL_INPUT VS_SCENE(VS_MODEL_INPUT input)178 {179     PS_MODEL_INPUT output = (PS_MODEL_INPUT)0;180     output.Pos = input.Pos;181     output.Pos.w = 1;182 183     output.Pos = mul( output.Pos, World );184     output.Pos = mul( output.Pos, View );185     output.Pos = mul( output.Pos, Projection );186     output.Pos = output.Pos / output.Pos.w;187 188     output.Norm = input.Norm;189     output.Tex = input.Tex;190     return output;191 }192 193 PS_MODEL_OUTPUT PS_SCENE(PS_MODEL_INPUT input)194 {195     PS_MODEL_OUTPUT output = (PS_MODEL_OUTPUT)0;196 197     float4 NormDepth = 0;198     NormDepth.rgb = input.Norm;//normal199     NormDepth.a = input.Pos.z;//depth200 201     output.NormDepth = NormDepth;202     output.DiffuseColor = g_ModelTexture.Sample( g_samWrap, input.Tex );203 204     return output;205 }206 //----------------------------------------------add ambient light to scene------------------------------------------------207 PS_SCENE_INPUT VS_Ambient(VS_QUAD_INPUT input)208 {209     PS_SCENE_INPUT output = (PS_SCENE_INPUT)0;210 211     float2 Pos = input.Pos.xy;212     output.Pos = float4(Pos.xy, 0, 1);213     214     output.Tex.x = 0.5 * (1 + Pos.x);215     output.Tex.y = 0.5 * (1 - Pos.y);216 217     return output;218 }219 220 PS_SCENE_OUTPUT PS_Ambient(PS_SCENE_INPUT input)221 {222     PS_SCENE_OUTPUT output = (PS_SCENE_OUTPUT)0;223 224     float4 DiffuseColor = g_DiffuseTexture.Sample( g_samClamp, input.Tex );225     float4 NormalDepth = g_NormDepthTexture.Sample( g_samClamp, input.Tex );226     float3 Normal = NormalDepth.rgb;227     float Depth = NormalDepth.a;228     float4 Pos = input.Pos;229 230     clip(Depth - 0.0001);231 232     output.Color = (g_AmbientColor + dot(normalize(g_DirLightDir), Normal) * g_DirLightColor) * DiffuseColor;233     output.Color.a = 1;234     output.Depth = Depth;235     236     return output;237 }238 //------------------------------calcuate depth test and set stencil value-------------------------------------------------------239 float4 PS_CalRadium(PS_MODEL_INPUT input) : SV_Target240 {   241     return float4(0.0, 1.0, 0.0, 0.3);//green light volumn242 }243 //-------------------------------------------------------------------------------------lit the area where stencil value is 1----------------------------------------------------------------------------------------244 float4 PS_LitScene(PS_SCENE_INPUT input) : SV_Target245 {246     return g_LocalLightColor;247 }248 //---------------------------------------------------------------------------------------------------------249 technique10 RenderScene250 {251     pass p0252     {253         SetVertexShader( CompileShader( vs_4_0, VS_SCENE() ) );254         SetGeometryShader( NULL );255         SetPixelShader( CompileShader( ps_4_0, PS_SCENE() ) );256 257         SetBlendState( NoBlending, float4( 0.0f, 0.0f, 0.0f, 0.0f ), 0xFFFFFFFF );258         SetDepthStencilState( EnableDepth, 0 );259         SetRasterizerState( EnableCulling );260 261         //SetRasterizerState( FrontCulling );262     }  263 }264 265 technique10 AmbientLighting266 {267     pass p0268     {269         SetVertexShader( CompileShader( vs_4_0, VS_Ambient() ) );270         SetGeometryShader( NULL );271         SetPixelShader( CompileShader( ps_4_0, PS_Ambient() ) );272 273         SetBlendState( NoBlending, float4( 0.0f, 0.0f, 0.0f, 0.0f ), 0xFFFFFFFF );274         SetDepthStencilState( EnableDepth, 0 );//render all model on texture, no depth test is needed275         SetRasterizerState( EnableCulling );276     }  277 }278 279 technique10 CalRadium280 {281     pass p0282     {283         SetVertexShader( CompileShader( vs_4_0, VS_SCENE() ) );284         SetGeometryShader( NULL );285         SetPixelShader( CompileShader( ps_4_0, PS_CalRadium() ) );286 287         SetBlendState( AlphaBlendingOn, float4( 0.0f, 0.0f, 0.0f, 0.0f ), 0xFFFFFFFF );288         //SetBlendState( DisableFrameBuffer, float4( 0.0f, 0.0f, 0.0f, 0.0f ), 0xFFFFFFFF );//don't render color to render target289         SetDepthStencilState( TwoSidedStencil, 1 ); //do depth fail test, write to stencil buffer290         SetRasterizerState( DisableCulling );//no culling, so both front and back face could be tested291     }  292 }293 294 technique10 LitScene295 {296     pass p0297     {298         SetVertexShader( CompileShader( vs_4_0, VS_Ambient() ) );299         SetGeometryShader( NULL );300         SetPixelShader( CompileShader( ps_4_0, PS_LitScene() ) );301 302         SetBlendState( AdditiveBlending, float4( 0.0f, 0.0f, 0.0f, 0.0f ), 0xFFFFFFFF );303         SetDepthStencilState( RenderNonShadows, 1); //when stencil value is 0, stencil fun pass and lit that pixel304         SetRasterizerState( EnableCulling );305     }  306 }