Making material transparant in Universal RP

BlueMarker · December 23, 2021, 7:17pm

For an AEC project I’d like to fade away doors when the camera comes near. To do this I’m changing the material transparency in game. Unfortunately I can’t get the material to show transparent.

The following code sets the material (Universal Render Pipeline/Lit) to the surface type transparent and changes the alpha value of the Base Map. This only works partially. When I test this; initially nothing seems to happen, except that I can see the material name has changed in the Inspector. But, when I open the material (instance) settings, while I’m in game mode, it starts working all of a sudden. I feel like using the Inspector does something I don’t understand.

   private void FadeThis(float inputAlpha)
    {
            var mats = GetComponent<Renderer>().materials;
            var newMats = new Material[mats.Length];

            for (var i = 0; i < mats.Length; i++)
            {
                var mat = new Material(mats[i]);

               // Set surface type to Transparent
                mat.SetFloat("_Surface", 1.0f);

               // Set Blending Mode to Alpha
                mat.SetFloat("_Blend", 0.0f);     

               // Set alpha
                mat.color = new Color(mat.color.r, mat.color.g, mat.color.b, inputAlpha);  
               
                newMats[i] = mat;
            }
            GetComponent<Renderer>().materials = newMats;
    }

Side note: this works just fine when I’m changing the material colors only. Specifically the transparency is an issue.

Does someone know what I’m missing? Any help would be greatly appreciated!

Yseron · December 23, 2021, 9:29pm

Could not reproduce the problem on my end, with or without “per instance” option ON/OFF: check the names of the shader properties (2 underscores, not one). For exemple its “**__**surface” not “_surface” (see Unity shader code at the bottom).

Link to test project: TRANSPARENT.zip - Google Drive

More importantly:
Unity dev on switching surface type to transparent from code: HDRP - Make surface transparent in runtime

using System;
using System.Collections;
using System.Collections.Generic;
using UnityEngine;

//********************************************************************************
//
//********************************************************************************

[ ExecuteAlways ] public class TranspararencyCtlr : MonoBehaviour
{
    //****************************************************************************
    //
    //****************************************************************************

    static private readonly int PROP_SURFACE = Shader.PropertyToID( "__surface" );

    static private readonly int PROP_BLEND   = Shader.PropertyToID( "__blend"   );

    //****************************************************************************
    //
    //****************************************************************************

                           [ SerializeField ] private bool         m_per_instance = false;

    [ Range( 0.0f, 1.0f ) ][ SerializeField ] private float        m_alpha        = 1.0f;
                                                                            
                           [ SerializeField ] private MeshRenderer m_renderer     = null;
                                                                            
                           [ NonSerialized  ] private float        m_reflected    = 1.0f;

    //****************************************************************************
    //
    //****************************************************************************

    private void Awake()
    {
        if( m_renderer == null ) m_renderer = GetComponent< MeshRenderer >();
    }

    //****************************************************************************
    //
    //****************************************************************************

    private void ApplyAlpha()
    {
        if( m_renderer == null )    return;

        m_alpha = Mathf.Clamp01( m_alpha );


        if( m_reflected != m_alpha )
        {
            m_reflected  = m_alpha;


            bool transparent = m_alpha < 1.0f;

            Material[]  mats = ( m_per_instance ) ? m_renderer.materials : m_renderer.sharedMaterials;

            if( transparent )
            {
                for( int m = 0, cnt = mats.Length; m < cnt; ++m )
                {
                    Material mat = mats[ m ];

                    mat.SetFloat( PROP_SURFACE, 1.0f );

                    mat.SetFloat( PROP_BLEND,   0.0f );

                    Color col = mat.color; col = new Color( col.r, col.g, col.b, m_alpha );

                    mat.color = col;
                }
            }
            else
            {
                for( int m = 0, cnt = mats.Length; m < cnt; ++m )
                {
                    Material mat = mats[ m ];

                    mat.SetFloat( PROP_SURFACE, 0.0f );

                    Color col = mat.color; col = new Color( col.r, col.g, col.b, 1.0f );

                    mat.color = col;
                }
            }

            if( m_per_instance ) m_renderer.materials       = mats;

            else                 m_renderer.sharedMaterials = mats;
        }
    }

    //****************************************************************************
    //
    //****************************************************************************

    private void Update()
    {
        ApplyAlpha();
    }
}

Shader "Universal Render Pipeline/Lit"
{
    Properties
    {
        // Specular vs Metallic workflow
        [HideInInspector] _WorkflowMode("WorkflowMode", Float) = 1.0

        [MainTexture] _BaseMap("Albedo", 2D) = "white" {}
        [MainColor] _BaseColor("Color", Color) = (1,1,1,1)

        _Cutoff("Alpha Cutoff", Range(0.0, 1.0)) = 0.5

        _Smoothness("Smoothness", Range(0.0, 1.0)) = 0.5
        _GlossMapScale("Smoothness Scale", Range(0.0, 1.0)) = 1.0
        _SmoothnessTextureChannel("Smoothness texture channel", Float) = 0

        _Metallic("Metallic", Range(0.0, 1.0)) = 0.0
        _MetallicGlossMap("Metallic", 2D) = "white" {}

        _SpecColor("Specular", Color) = (0.2, 0.2, 0.2)
        _SpecGlossMap("Specular", 2D) = "white" {}

        [ToggleOff] _SpecularHighlights("Specular Highlights", Float) = 1.0
        [ToggleOff] _EnvironmentReflections("Environment Reflections", Float) = 1.0

        _BumpScale("Scale", Float) = 1.0
        _BumpMap("Normal Map", 2D) = "bump" {}

        _Parallax("Scale", Range(0.005, 0.08)) = 0.005
        _ParallaxMap("Height Map", 2D) = "black" {}

        _OcclusionStrength("Strength", Range(0.0, 1.0)) = 1.0
        _OcclusionMap("Occlusion", 2D) = "white" {}

        [HDR] _EmissionColor("Color", Color) = (0,0,0)
        _EmissionMap("Emission", 2D) = "white" {}

        _DetailMask("Detail Mask", 2D) = "white" {}
        _DetailAlbedoMapScale("Scale", Range(0.0, 2.0)) = 1.0
        _DetailAlbedoMap("Detail Albedo x2", 2D) = "linearGrey" {}
        _DetailNormalMapScale("Scale", Range(0.0, 2.0)) = 1.0
        [Normal] _DetailNormalMap("Normal Map", 2D) = "bump" {}

        // SRP batching compatibility for Clear Coat (Not used in Lit)
        [HideInInspector] _ClearCoatMask("_ClearCoatMask", Float) = 0.0
        [HideInInspector] _ClearCoatSmoothness("_ClearCoatSmoothness", Float) = 0.0

        // Blending state
        [HideInInspector] _Surface("__surface", Float) = 0.0
        [HideInInspector] _Blend("__blend", Float) = 0.0
        [HideInInspector] _AlphaClip("__clip", Float) = 0.0
        [HideInInspector] _SrcBlend("__src", Float) = 1.0
        [HideInInspector] _DstBlend("__dst", Float) = 0.0
        [HideInInspector] _ZWrite("__zw", Float) = 1.0
        [HideInInspector] _Cull("__cull", Float) = 2.0

        _ReceiveShadows("Receive Shadows", Float) = 1.0
        // Editmode props
        [HideInInspector] _QueueOffset("Queue offset", Float) = 0.0

        // ObsoleteProperties
        [HideInInspector] _MainTex("BaseMap", 2D) = "white" {}
        [HideInInspector] _Color("Base Color", Color) = (1, 1, 1, 1)
        [HideInInspector] _GlossMapScale("Smoothness", Float) = 0.0
        [HideInInspector] _Glossiness("Smoothness", Float) = 0.0
        [HideInInspector] _GlossyReflections("EnvironmentReflections", Float) = 0.0

        [HideInInspector][NoScaleOffset]unity_Lightmaps("unity_Lightmaps", 2DArray) = "" {}
        [HideInInspector][NoScaleOffset]unity_LightmapsInd("unity_LightmapsInd", 2DArray) = "" {}
        [HideInInspector][NoScaleOffset]unity_ShadowMasks("unity_ShadowMasks", 2DArray) = "" {}
    }

    SubShader
    {
        // Universal Pipeline tag is required. If Universal render pipeline is not set in the graphics settings
        // this Subshader will fail. One can add a subshader below or fallback to Standard built-in to make this
        // material work with both Universal Render Pipeline and Builtin Unity Pipeline
        Tags{"RenderType" = "Opaque" "RenderPipeline" = "UniversalPipeline" "UniversalMaterialType" = "Lit" "IgnoreProjector" = "True" "ShaderModel"="4.5"}
        LOD 300

        // ------------------------------------------------------------------
        //  Forward pass. Shades all light in a single pass. GI + emission + Fog
        Pass
        {
            // Lightmode matches the ShaderPassName set in UniversalRenderPipeline.cs. SRPDefaultUnlit and passes with
            // no LightMode tag are also rendered by Universal Render Pipeline
            Name "ForwardLit"
            Tags{"LightMode" = "UniversalForward"}

            Blend[_SrcBlend][_DstBlend]
            ZWrite[_ZWrite]
            Cull[_Cull]

            HLSLPROGRAM
            #pragma exclude_renderers gles gles3 glcore
            #pragma target 4.5

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local _NORMALMAP
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _ALPHAPREMULTIPLY_ON
            #pragma shader_feature_local_fragment _EMISSION
            #pragma shader_feature_local_fragment _METALLICSPECGLOSSMAP
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
            #pragma shader_feature_local_fragment _OCCLUSIONMAP
            #pragma shader_feature_local _PARALLAXMAP
            #pragma shader_feature_local _ _DETAIL_MULX2 _DETAIL_SCALED
            #pragma shader_feature_local_fragment _SPECULARHIGHLIGHTS_OFF
            #pragma shader_feature_local_fragment _ENVIRONMENTREFLECTIONS_OFF
            #pragma shader_feature_local_fragment _SPECULAR_SETUP
            #pragma shader_feature_local _RECEIVE_SHADOWS_OFF

            // -------------------------------------
            // Universal Pipeline keywords
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE
            #pragma multi_compile _ _ADDITIONAL_LIGHTS_VERTEX _ADDITIONAL_LIGHTS
            #pragma multi_compile_fragment _ _ADDITIONAL_LIGHT_SHADOWS
            #pragma multi_compile_fragment _ _SHADOWS_SOFT
            #pragma multi_compile_fragment _ _SCREEN_SPACE_OCCLUSION
            #pragma multi_compile _ LIGHTMAP_SHADOW_MIXING
            #pragma multi_compile _ SHADOWS_SHADOWMASK

            // -------------------------------------
            // Unity defined keywords
            #pragma multi_compile _ DIRLIGHTMAP_COMBINED
            #pragma multi_compile _ LIGHTMAP_ON
            #pragma multi_compile_fog

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing
            #pragma multi_compile _ DOTS_INSTANCING_ON

            #pragma vertex LitPassVertex
            #pragma fragment LitPassFragment

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitForwardPass.hlsl"
            ENDHLSL
        }

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

            ZWrite On
            ZTest LEqual
            ColorMask 0
            Cull[_Cull]

            HLSLPROGRAM
            #pragma exclude_renderers gles gles3 glcore
            #pragma target 4.5

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing
            #pragma multi_compile _ DOTS_INSTANCING_ON

            #pragma vertex ShadowPassVertex
            #pragma fragment ShadowPassFragment

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/ShadowCasterPass.hlsl"
            ENDHLSL
        }

        Pass
        {
            // Lightmode matches the ShaderPassName set in UniversalRenderPipeline.cs. SRPDefaultUnlit and passes with
            // no LightMode tag are also rendered by Universal Render Pipeline
            Name "GBuffer"
            Tags{"LightMode" = "UniversalGBuffer"}

            ZWrite[_ZWrite]
            ZTest LEqual
            Cull[_Cull]

            HLSLPROGRAM
            #pragma exclude_renderers gles gles3 glcore
            #pragma target 4.5

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local _NORMALMAP
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            //#pragma shader_feature_local_fragment _ALPHAPREMULTIPLY_ON
            #pragma shader_feature_local_fragment _EMISSION
            #pragma shader_feature_local_fragment _METALLICSPECGLOSSMAP
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
            #pragma shader_feature_local_fragment _OCCLUSIONMAP
            #pragma shader_feature_local _PARALLAXMAP
            #pragma shader_feature_local _ _DETAIL_MULX2 _DETAIL_SCALED

            #pragma shader_feature_local_fragment _SPECULARHIGHLIGHTS_OFF
            #pragma shader_feature_local_fragment _ENVIRONMENTREFLECTIONS_OFF
            #pragma shader_feature_local_fragment _SPECULAR_SETUP
            #pragma shader_feature_local _RECEIVE_SHADOWS_OFF

            // -------------------------------------
            // Universal Pipeline keywords
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE
            //#pragma multi_compile _ _ADDITIONAL_LIGHTS_VERTEX _ADDITIONAL_LIGHTS
            //#pragma multi_compile _ _ADDITIONAL_LIGHT_SHADOWS
            #pragma multi_compile _ _SHADOWS_SOFT
            #pragma multi_compile _ _MIXED_LIGHTING_SUBTRACTIVE

            // -------------------------------------
            // Unity defined keywords
            #pragma multi_compile _ DIRLIGHTMAP_COMBINED
            #pragma multi_compile _ LIGHTMAP_ON
            #pragma multi_compile_fragment _ _GBUFFER_NORMALS_OCT

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing
            #pragma multi_compile _ DOTS_INSTANCING_ON

            #pragma vertex LitGBufferPassVertex
            #pragma fragment LitGBufferPassFragment

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitGBufferPass.hlsl"
            ENDHLSL
        }

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

            ZWrite On
            ColorMask 0
            Cull[_Cull]

            HLSLPROGRAM
            #pragma exclude_renderers gles gles3 glcore
            #pragma target 4.5

            #pragma vertex DepthOnlyVertex
            #pragma fragment DepthOnlyFragment

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing
            #pragma multi_compile _ DOTS_INSTANCING_ON

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/DepthOnlyPass.hlsl"
            ENDHLSL
        }

        // This pass is used when drawing to a _CameraNormalsTexture texture
        Pass
        {
            Name "DepthNormals"
            Tags{"LightMode" = "DepthNormals"}

            ZWrite On
            Cull[_Cull]

            HLSLPROGRAM
            #pragma exclude_renderers gles gles3 glcore
            #pragma target 4.5

            #pragma vertex DepthNormalsVertex
            #pragma fragment DepthNormalsFragment

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local _NORMALMAP
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing
            #pragma multi_compile _ DOTS_INSTANCING_ON

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/DepthNormalsPass.hlsl"
            ENDHLSL
        }

        // This pass it not used during regular rendering, only for lightmap baking.
        Pass
        {
            Name "Meta"
            Tags{"LightMode" = "Meta"}

            Cull Off

            HLSLPROGRAM
            #pragma exclude_renderers gles gles3 glcore
            #pragma target 4.5

            #pragma vertex UniversalVertexMeta
            #pragma fragment UniversalFragmentMeta

            #pragma shader_feature_local_fragment _SPECULAR_SETUP
            #pragma shader_feature_local_fragment _EMISSION
            #pragma shader_feature_local_fragment _METALLICSPECGLOSSMAP
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
            #pragma shader_feature_local _ _DETAIL_MULX2 _DETAIL_SCALED

            #pragma shader_feature_local_fragment _SPECGLOSSMAP

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitMetaPass.hlsl"

            ENDHLSL
        }
        Pass
        {
            Name "Universal2D"
            Tags{ "LightMode" = "Universal2D" }

            Blend[_SrcBlend][_DstBlend]
            ZWrite[_ZWrite]
            Cull[_Cull]

            HLSLPROGRAM
            #pragma exclude_renderers gles gles3 glcore
            #pragma target 4.5

            #pragma vertex vert
            #pragma fragment frag
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _ALPHAPREMULTIPLY_ON

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/Utils/Universal2D.hlsl"
            ENDHLSL
        }
    }

    SubShader
    {
        // Universal Pipeline tag is required. If Universal render pipeline is not set in the graphics settings
        // this Subshader will fail. One can add a subshader below or fallback to Standard built-in to make this
        // material work with both Universal Render Pipeline and Builtin Unity Pipeline
        Tags{"RenderType" = "Opaque" "RenderPipeline" = "UniversalPipeline" "UniversalMaterialType" = "Lit" "IgnoreProjector" = "True" "ShaderModel"="2.0"}
        LOD 300

        // ------------------------------------------------------------------
        //  Forward pass. Shades all light in a single pass. GI + emission + Fog
        Pass
        {
            // Lightmode matches the ShaderPassName set in UniversalRenderPipeline.cs. SRPDefaultUnlit and passes with
            // no LightMode tag are also rendered by Universal Render Pipeline
            Name "ForwardLit"
            Tags{"LightMode" = "UniversalForward"}

            Blend[_SrcBlend][_DstBlend]
            ZWrite[_ZWrite]
            Cull[_Cull]

            HLSLPROGRAM
            #pragma only_renderers gles gles3 glcore d3d11
            #pragma target 2.0

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local _NORMALMAP
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _ALPHAPREMULTIPLY_ON
            #pragma shader_feature_local_fragment _EMISSION
            #pragma shader_feature_local_fragment _METALLICSPECGLOSSMAP
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
            #pragma shader_feature_local_fragment _OCCLUSIONMAP
            #pragma shader_feature_local _PARALLAXMAP
            #pragma shader_feature_local _ _DETAIL_MULX2 _DETAIL_SCALED

            #pragma shader_feature_local_fragment _SPECULARHIGHLIGHTS_OFF
            #pragma shader_feature_local_fragment _ENVIRONMENTREFLECTIONS_OFF
            #pragma shader_feature_local_fragment _SPECULAR_SETUP
            #pragma shader_feature_local _RECEIVE_SHADOWS_OFF

            // -------------------------------------
            // Universal Pipeline keywords
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS
            #pragma multi_compile _ _MAIN_LIGHT_SHADOWS_CASCADE
            #pragma multi_compile _ _ADDITIONAL_LIGHTS_VERTEX _ADDITIONAL_LIGHTS
            #pragma multi_compile_fragment _ _ADDITIONAL_LIGHT_SHADOWS
            #pragma multi_compile_fragment _ _SHADOWS_SOFT
            #pragma multi_compile _ LIGHTMAP_SHADOW_MIXING
            #pragma multi_compile _ SHADOWS_SHADOWMASK
            #pragma multi_compile_fragment _ _SCREEN_SPACE_OCCLUSION

            // -------------------------------------
            // Unity defined keywords
            #pragma multi_compile _ DIRLIGHTMAP_COMBINED
            #pragma multi_compile _ LIGHTMAP_ON
            #pragma multi_compile_fog

            #pragma vertex LitPassVertex
            #pragma fragment LitPassFragment

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitForwardPass.hlsl"
            ENDHLSL
        }

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

            ZWrite On
            ZTest LEqual
            ColorMask 0
            Cull[_Cull]

            HLSLPROGRAM
            #pragma only_renderers gles gles3 glcore d3d11
            #pragma target 2.0

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A

            #pragma vertex ShadowPassVertex
            #pragma fragment ShadowPassFragment

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/ShadowCasterPass.hlsl"
            ENDHLSL
        }

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

            ZWrite On
            ColorMask 0
            Cull[_Cull]

            HLSLPROGRAM
            #pragma only_renderers gles gles3 glcore d3d11
            #pragma target 2.0

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing

            #pragma vertex DepthOnlyVertex
            #pragma fragment DepthOnlyFragment

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/DepthOnlyPass.hlsl"
            ENDHLSL
        }

        // This pass is used when drawing to a _CameraNormalsTexture texture
        Pass
        {
            Name "DepthNormals"
            Tags{"LightMode" = "DepthNormals"}

            ZWrite On
            Cull[_Cull]

            HLSLPROGRAM
            #pragma only_renderers gles gles3 glcore d3d11
            #pragma target 2.0

            #pragma vertex DepthNormalsVertex
            #pragma fragment DepthNormalsFragment

            // -------------------------------------
            // Material Keywords
            #pragma shader_feature_local _NORMALMAP
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A

            //--------------------------------------
            // GPU Instancing
            #pragma multi_compile_instancing

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/DepthNormalsPass.hlsl"
            ENDHLSL
        }

        // This pass it not used during regular rendering, only for lightmap baking.
        Pass
        {
            Name "Meta"
            Tags{"LightMode" = "Meta"}

            Cull Off

            HLSLPROGRAM
            #pragma only_renderers gles gles3 glcore d3d11
            #pragma target 2.0

            #pragma vertex UniversalVertexMeta
            #pragma fragment UniversalFragmentMeta

            #pragma shader_feature_local_fragment _SPECULAR_SETUP
            #pragma shader_feature_local_fragment _EMISSION
            #pragma shader_feature_local_fragment _METALLICSPECGLOSSMAP
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _ _SMOOTHNESS_TEXTURE_ALBEDO_CHANNEL_A
            #pragma shader_feature_local _ _DETAIL_MULX2 _DETAIL_SCALED

            #pragma shader_feature_local_fragment _SPECGLOSSMAP

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitMetaPass.hlsl"

            ENDHLSL
        }
        Pass
        {
            Name "Universal2D"
            Tags{ "LightMode" = "Universal2D" }

            Blend[_SrcBlend][_DstBlend]
            ZWrite[_ZWrite]
            Cull[_Cull]

            HLSLPROGRAM
            #pragma only_renderers gles gles3 glcore d3d11
            #pragma target 2.0

            #pragma vertex vert
            #pragma fragment frag
            #pragma shader_feature_local_fragment _ALPHATEST_ON
            #pragma shader_feature_local_fragment _ALPHAPREMULTIPLY_ON

            #include "Packages/com.unity.render-pipelines.universal/Shaders/LitInput.hlsl"
            #include "Packages/com.unity.render-pipelines.universal/Shaders/Utils/Universal2D.hlsl"
            ENDHLSL
        }
    }

    FallBack "Hidden/Universal Render Pipeline/FallbackError"
    CustomEditor "UnityEditor.Rendering.Universal.ShaderGUI.LitShader"
}

BlueMarker · December 25, 2021, 9:19am

Dear Serge,

Thank you kindly for your elaborate reply!

It seems that the result is different on my system for some reason, I’m getting the same results as before with your code. See attached video (repeating Gif) to clarify what I’m seeing.

I did make a small change to the code though, I changed the following line:

static private readonly int PROP_SURFACE = Shader.PropertyToID( "__surface" );

To this:

static private readonly int PROP_SURFACE = Shader.PropertyToID("_Surface");

It did not change the Surface Type otherwise. I hope this did not effect the outcome.

The link you’ve send makes me worried that this might indeed not be possible. The quotation from the developer is:

I am new to Unity and scripting in general, I’m afraid this might be a silly question: Is it possible to change the material Instance settings before it is compiled? It’s OK, if the material surface type is transparent all the time. (Awake() does not do this.)

Elaborating further on why I don’t just change the material before runtime: I retrieve the models and materials using Unity Reflect. These models/materials get imported from a Revit model. Reflect synchronizes this data, which is very useful. This also means I can’t just change materials before runtime since they would not be synchronized any more.

Yseron · December 25, 2021, 1:06pm

Changing from "__surface’ back to your “_Surface” and not forcing the material surface type to transparent in the edtor because changing it from code is ineffective for the reason previously explained is precisely why because why it works for me and not for you. So yes it is OK to have a material who is always set to transparent since it is what the Unity dev advise in his post that I had included in mine when initially answering your question.

If you receive your materials from a third party and are not allowed to change them at edit time, then it is with the authors of said third party that you must seek a solution since Unity is unlikely to change the way the shader surface type is allowed to be changed dynamically at run time. Or if you are anough people to request that something be done on the matter they wil maybe look into it but not before some delay.

BlueMarker · December 25, 2021, 4:23pm

Ow right, sorry I misunderstood. In your sample you had set the material to transparent before runtime. That makes sense.

I should have been more clear on that the Opaque setting is a direct result of synchronizing between CAD-model and Unity. The way Unity Reflect synchronizes the data will require me to break the link to the CAD-model, just to be able to modify any material settings. That’s why I intended to change the Instance of the material and not the ‘shared’ material. (If I’m not mistaking I can only change/create a material instance at runtime?)

I guess that my next step should be to create copies of all materials before runtime. Set the surface type to Transparent. Then during runtime replace the gameObject’s materials with the copies.

Thanks for helping out! I was clearly not on the right track here!

Renardjojo · September 21, 2023, 1:56pm

This is something you can easily change in URP, but you need to know how embedded the URP package and how the multicompilation keyword works. This is a Unity design to limit the number of shaders, but you can change it.
For example, to change opac to transparent shader graph shader I change this line

        public static readonly KeywordDescriptor SurfaceTypeTransparent = new KeywordDescriptor()
        {
            displayName = ShaderKeywordStrings._SURFACE_TYPE_TRANSPARENT,
            referenceName = ShaderKeywordStrings._SURFACE_TYPE_TRANSPARENT,
            type = KeywordType.Boolean,
            definition = KeywordDefinition.ShaderFeature,
            scope = KeywordScope.Global, // needs to match HDRP
            stages = KeywordShaderStage.Fragment,
        };

to

public static readonly KeywordDescriptor SurfaceTypeTransparent = new KeywordDescriptor()
{
    displayName = ShaderKeywordStrings._SURFACE_TYPE_TRANSPARENT,
    referenceName = ShaderKeywordStrings._SURFACE_TYPE_TRANSPARENT,
    type = KeywordType.Boolean,
    definition = KeywordDefinition.MultiCompile,
    scope = KeywordScope.Global, // needs to match HDRP
    stages = KeywordShaderStage.Fragment,
};

in universalTargets.cs

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Making material transparant in Universal RP

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