【Unity开发】低版本HDRenderPipeline升级到HDRP14.x版本问题笔记

1、 Shader兼容问题

1.1 Undefined area shadow filter algorithm

	Shader error in 'Stream_HD': "Undefined area shadow filter algorithm" at /Prj_Unity/Scenes/XXX/Library/PackageCache/com.unity.render-pipelines.high-definition@14.0.11/Runtime/Lighting/Shadow/HDShadowAlgorithms.hlsl(53)
Compiling Subshader: 0, Pass: Forward, Fragment program with DECALS_OFF SHADOW_LOW USE_FPTL_LIGHTLIST
Platform defines: SHADER_API_DESKTOP UNITY_ENABLE_DETAIL_NORMALMAP UNITY_ENABLE_REFLECTION_BUFFERS UNITY_LIGHTMAP_FULL_HDR UNITY_LIGHT_PROBE_PROXY_VOLUME UNITY_PBS_USE_BRDF1 UNITY_SPECCUBE_BLENDING UNITY_SPECCUBE_BOX_PROJECTION UNITY_USE_DITHER_MASK_FOR_ALPHABLENDED_SHADOWS
Disabled keywords: DEBUG_DISPLAY DECALS_3RT DECALS_4RT DIRLIGHTMAP_COMBINED DYNAMICLIGHTMAP_ON INSTANCING_ON LIGHTMAP_ON SHADER_API_GLES30 SHADOWS_SHADOWMASK SHADOW_HIGH SHADOW_MEDIUM UNITY_ASTC_NORMALMAP_ENCODING UNITY_COLORSPACE_GAMMA UNITY_FRAMEBUFFER_FETCH_AVAILABLE UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS UNITY_HARDWARE_TIER1 UNITY_HARDWARE_TIER2 UNITY_HARDWARE_TIER3 UNITY_LIGHTMAP_DLDR_ENCODING UNITY_LIGHTMAP_RGBM_ENCODING UNITY_METAL_SHADOWS_USE_POINT_FILTERING UNITY_NO_DXT5nm UNITY_NO_FULL_STANDARD_SHADER UNITY_NO_SCREENSPACE_SHADOWS UNITY_PBS_USE_BRDF2 UNITY_PBS_USE_BRDF3 UNITY_PRETRANSFORM_TO_DISPLAY_ORIENTATION UNITY_UNIFIED_SHADER_PRECISION_MODEL UNITY_VIRTUAL_TEXTURING USE_CLUSTERED_LIGHTLIST _ALPHATEST_ON _DOUBLESIDED_ON _ENABLE_FOG_ON_TRANSPARENT _SURFACE_TYPE_TRANSPARENT

1.1.1 找到Shader中HLSLPROGRAM标记

Pass
{
    Name "xxx"
    Tags
    {
		...
    }
    Cull [_CullModeForward]
		...
    HLSLPROGRAM
		就是这里
}

1.1.2 添加Pragma指令，让Shader能够正确编译并选择适当的阴影过滤算法

			// Pragmas HDRP 10+ 版本的area shadow算法编译指令
			#pragma multi_compile _ DOTS_INSTANCING_ON
			#pragma instancing_options renderinglayer
			#pragma multi_compile_fragment AREA_SHADOW_MEDIUM AREA_SHADOW_HIGH

示例

		Pass
		{
			Name "Forward"
			Tags { "LightMode"="Forward" }

			Blend [_SrcBlend] [_DstBlend], [_AlphaSrcBlend] [_AlphaDstBlend]
			Cull [_CullModeForward]
			ZTest [_ZTestDepthEqualForOpaque]
			ZWrite [_ZWrite]

			Stencil
			{
				Ref [_StencilRef]
				WriteMask [_StencilWriteMask]
				Comp Always
				Pass Replace
				Fail Keep
				ZFail Keep
			}


			ColorMask [_ColorMaskTransparentVel]

			HLSLPROGRAM

			// Pragmas HDRP 10+ 版本的area shadow算法编译指令
			#pragma multi_compile _ DOTS_INSTANCING_ON
			#pragma instancing_options renderinglayer
			#pragma multi_compile_fragment AREA_SHADOW_MEDIUM AREA_SHADOW_HIGH

			... 其他原代码

1.1.3 为所有Pass添加area shadow算法编译指令

找出Shader中所有的Pass，添加以上指令，就能解决"Undefined area shadow filter algorithm" 报错了。

1.2 ‘LightLoop’: cannot convert output parameter from ‘struct LightLoopOutput’ to ‘float3’ at

Shader error in 'Stream_HD': 'LightLoop': cannot convert output parameter from 'struct LightLoopOutput' to 'float3' at Pack/Shaders/Stream_HD.shader(4407) (on d3d11)

Compiling Subshader: 0, Pass: Forward, Fragment program with AREA_SHADOW_MEDIUM DECALS_OFF SHADOW_LOW USE_FPTL_LIGHTLIST
Platform defines: SHADER_API_DESKTOP UNITY_ENABLE_DETAIL_NORMALMAP UNITY_ENABLE_REFLECTION_BUFFERS UNITY_LIGHTMAP_FULL_HDR UNITY_LIGHT_PROBE_PROXY_VOLUME UNITY_PBS_USE_BRDF1 UNITY_SPECCUBE_BLENDING UNITY_SPECCUBE_BOX_PROJECTION UNITY_USE_DITHER_MASK_FOR_ALPHABLENDED_SHADOWS
Disabled keywords: AREA_SHADOW_HIGH DEBUG_DISPLAY DECALS_3RT DECALS_4RT DIRLIGHTMAP_COMBINED DOTS_INSTANCING_ON DYNAMICLIGHTMAP_ON INSTANCING_ON LIGHTMAP_ON SHADER_API_GLES30 SHADOWS_SHADOWMASK SHADOW_HIGH SHADOW_MEDIUM UNITY_ASTC_NORMALMAP_ENCODING UNITY_COLORSPACE_GAMMA UNITY_FRAMEBUFFER_FETCH_AVAILABLE UNITY_HALF_PRECISION_FRAGMENT_SHADER_REGISTERS UNITY_HARDWARE_TIER1 UNITY_HARDWARE_TIER2 UNITY_HARDWARE_TIER3 UNITY_LIGHTMAP_DLDR_ENCODING UNITY_LIGHTMAP_RGBM_ENCODING UNITY_METAL_SHADOWS_USE_POINT_FILTERING UNITY_NO_DXT5nm UNITY_NO_FULL_STANDARD_SHADER UNITY_NO_SCREENSPACE_SHADOWS UNITY_PBS_USE_BRDF2 UNITY_PBS_USE_BRDF3 UNITY_PRETRANSFORM_TO_DISPLAY_ORIENTATION UNITY_UNIFIED_SHADER_PRECISION_MODEL UNITY_VIRTUAL_TEXTURING USE_CLUSTERED_LIGHTLIST _ALPHATEST_ON _DOUBLESIDED_ON _ENABLE_FOG_ON_TRANSPARENT _SURFACE_TYPE_TRANSPARENT

1.2.1 修正参数声明

float3 diffuseLighting;
float3 specularLighting;

变更为

LightLoopOutput lightLoopOutput;

1.2.2 修正函数中使用参数方法

LightLoop(V, posInput, preLightData, bsdfData, builtinData, featureFlags, diffuseLighting, specularLighting);

变更为

LightLoop(V, posInput, preLightData, bsdfData, builtinData, featureFlags, lightLoopOutput);

1.2.3 修正变量取值方法

diffuseLighting *= GetCurrentExposureMultiplier();
specularLighting *= GetCurrentExposureMultiplier();

变更为

float3 diffuseLighting = lightLoopOutput.diffuseLighting;
float3 specularLighting = lightLoopOutput.specularLighting;
diffuseLighting *= GetCurrentExposureMultiplier();
specularLighting *= GetCurrentExposureMultiplier();

1.2.4 完整代码

// 旧版本 
/*float3 diffuseLighting;
float3 specularLighting;
LightLoop(V, posInput, preLightData, bsdfData, builtinData, featureFlags, diffuseLighting, specularLighting);
diffuseLighting *= GetCurrentExposureMultiplier();
specularLighting *= GetCurrentExposureMultiplier();*/

// 替换Unity HDRP 10+版本
LightLoopOutput lightLoopOutput;
LightLoop(V, posInput, preLightData, bsdfData, builtinData, featureFlags, lightLoopOutput);
float3 diffuseLighting = lightLoopOutput.diffuseLighting;
float3 specularLighting = lightLoopOutput.specularLighting;
diffuseLighting *= GetCurrentExposureMultiplier();
specularLighting *= GetCurrentExposureMultiplier();