I am trying to "merge" the code of two shaders:
The first one is a double sided shader for Hololens from the Microsoft Holotoolkit:
// Copyright (c) Microsoft Corporation. All rights reserved.
// Licensed under the MIT License. See LICENSE in the project root for license information.
Shader "MixedRealityToolkit/Obsolete/Fast Configurable 2 Sided"
{
Properties
{
_Mode("Rendering Mode", Float) = 0.0
[Toggle] _UseVertexColor("Vertex Color Enabled?", Float) = 0
[Toggle] _UseMainColor("Main Color Enabled?", Float) = 0
_Color("Main Color", Color) = (1,1,1,1)
[Toggle] _UseMainTex("Main Texture Enabled?", Float) = 0
[NoScaleOffset]_MainTex("Main Texture", 2D) = "red" {}
[Toggle] _UseOcclusionMap("Occlusion/Detail Texture Enabled?", Float) = 0
[NoScaleOffset]_OcclusionMap("Occlusion/Detail Texture", 2D) = "blue" {}
[Toggle] _UseAmbient("Ambient Lighting Enabled?", Float) = 1
[Toggle] _UseDiffuse("Diffuse Lighting Enabled?", Float) = 1
[Toggle] _SpecularHighlights("Specular Lighting Enabled?", Float) = 0
[Toggle] _Shade4("Use additional lighting data? (Expensive!)", Float) = 0
[Toggle] _ForcePerPixel("Light per-pixel (always on if a map is set)", Float) = 0
_SpecColor("Specular Color", Color) = (0.5, 0.5, 0.5, 1)
[PowerSlider(5.0)]_Specular("Specular (Specular Power)", Range(1.0, 100.0)) = 10.0
[Toggle] _UseSpecularMap("Use Specular Map? (per-pixel)", Float) = 0
[NoScaleOffset]_SpecularMap("Specular Map", 2D) = "white" {}
_Gloss("Gloss (Specular Scale)", Range(0.1, 10.0)) = 1.0
[Toggle] _UseGlossMap("Use Gloss Map? (per-pixel)", Float) = 0
[NoScaleOffset]_GlossMap("Gloss Map", 2D) = "white" {}
[Toggle] _UseBumpMap("Normal Map Enabled? (per-pixel)", Float) = 0
[NoScaleOffset][Normal] _BumpMap("Normal Map", 2D) = "bump" {}
[Toggle] _UseReflections("Reflections Enabled?", Float) = 0
[NoScaleOffset]_CubeMap("CubeMap", Cube) = "" {}
_ReflectionScale("Reflection Scale", Range(0.01, 3.0)) = 2.0
[Toggle]_CalibrationSpaceReflections("Reflect in calibration space?", Float) = 0
[Toggle] _UseRimLighting("Rim Lighting Enabled?", Float) = 0
[PowerSlider(.6)]_RimPower("Power", Range(0.1, 1.0)) = 0.7
_RimColor("Color", Color) = (1,1,1,1)
[Toggle] _UseEmissionColor("Emission Color Enabled?", Float) = 0
_EmissionColor("Emission Color", Color) = (1,1,1,1)
[Toggle] _UseEmissionMap("Emission Map Enabled?", Float) = 0
[NoScaleOffset] _EmissionMap("Emission Map", 2D) = "blue" {}
_TextureScaleOffset("Texture Scale (XY) and Offset (ZW)", Vector) = (1, 1, 0, 0)
[Enum(UnityEngine.Rendering.BlendMode)] _SrcBlend("SrcBlend", Float) = 1 //"One"
[Enum(UnityEngine.Rendering.BlendMode)] _DstBlend("DestBlend", Float) = 0 //"Zero"
[Enum(UnityEngine.Rendering.BlendOp)] _BlendOp("BlendOp", Float) = 0 //"Add"
[Toggle] _AlphaTest("Alpha test enabled?", Float) = 0
_Cutoff("Alpha Cutoff", Range(-0.1, 1.0)) = -0.1
[Enum(UnityEngine.Rendering.CompareFunction)] _ZTest("ZTest", Float) = 4 //"LessEqual"
[Enum(Off,0,On,1)] _ZWrite("ZWrite", Float) = 1 //"On"
[Enum(UnityEngine.Rendering.ColorWriteMask)] _ColorWriteMask("ColorWriteMask", Float) = 15 //"All"
}
SubShader
{
Tags { "RenderType"="Opaque" "PerformanceChecks"="False" }
LOD 100
Blend[_SrcBlend][_DstBlend]
BlendOp[_BlendOp]
ZTest[_ZTest]
ZWrite[_ZWrite]
Pass
{
Name "FRONT"
Tags { "LightMode" = "ForwardBase" }
Cull Back
ColorMask[_ColorWriteMask]
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
//compiles all variants needed by ForwardBase (forward rendering base) pass type. The variants deal with different lightmap types and main directional light having shadows on or off.
#pragma multi_compile_fwdbase
//expands to several variants to handle different fog types
#pragma multi_compile_fog
//We only target the HoloLens (and the Unity editor), so take advantage of shader model 5.
#pragma target 5.0
#pragma only_renderers d3d11
//shader features are only compiled if a material uses them
#pragma shader_feature _USEVERTEXCOLOR_ON
#pragma shader_feature _USEMAINCOLOR_ON
#pragma shader_feature _USEMAINTEX_ON
#pragma shader_feature _USESOCCLUSIONMAP_ON
#pragma shader_feature _USEBUMPMAP_ON
#pragma shader_feature _USEAMBIENT_ON
#pragma shader_feature _USEDIFFUSE_ON
#pragma shader_feature _USESPECULAR_ON
#pragma shader_feature _USEGLOSSMAP_ON
#pragma shader_feature _SHADE4_ON
#pragma shader_feature _USEREFLECTIONS_ON
#pragma shader_feature _USERIMLIGHTING_ON
#pragma shader_feature _USEEMISSIONCOLOR_ON
#pragma shader_feature _USEEMISSIONTEX_ON
#pragma shader_feature _ALPHATEST_ON
//scale and offset will apply to all
#pragma shader_feature _MainTex_SCALE_ON
#pragma shader_feature _MainTex_OFFSET_ON
//may be set from script so generate both paths
#pragma multi_compile __ _NEAR_PLANE_FADE_ON
#include "FastConfigurable.cginc"
ENDCG
}
Pass
{
Name "BACK"
Tags{ "LightMode" = "ForwardBase" }
Cull Front
ColorMask[_ColorWriteMask]
CGPROGRAM
#pragma vertex vert
#pragma fragment frag
//compiles all variants needed by ForwardBase (forward rendering base) pass type. The variants deal with different lightmap types and main directional light having shadows on or off.
#pragma multi_compile_fwdbase
//expands to several variants to handle different fog types
#pragma multi_compile_fog
//We only target the HoloLens (and the Unity editor), so take advantage of shader model 5.
#pragma target 5.0
#pragma only_renderers d3d11
//shader features are only compiled if a material uses them
#pragma shader_feature _USEMAINCOLOR_ON
#pragma shader_feature _USEMAINTEX_ON
#pragma shader_feature _USESOCCLUSIONMAP_ON
#pragma shader_feature _USEBUMPMAP_ON
#pragma shader_feature _USEAMBIENT_ON
#pragma shader_feature _USEDIFFUSE_ON
#pragma shader_feature _USESPECULAR_ON
#pragma shader_feature _USEGLOSSMAP_ON
#pragma shader_feature _SHADE4_ON
#pragma shader_feature _USEEMISSIONCOLOR_ON
#pragma shader_feature _USEEMISSIONTEX_ON
//scale and offset will apply to all
#pragma shader_feature _MainTex_SCALE_ON
#pragma shader_feature _MainTex_OFFSET_ON
//may be set from script so generate both paths
#pragma multi_compile __ _NEAR_PLANE_FADE_ON
#define FLIP_NORMALS 1
#include "FastConfigurable.cginc"
ENDCG
}
}
CustomEditor "HoloToolkit.Unity.FastConfigurable2SidedGUI"
Fallback "VertexLit" //for shadows
}
The second one is a cross section shader from the Unity asset store:
Shader "CrossSection/OnePlaneBSP" {
Properties{
_Color("Color", Color) = (1,1,1,1)
_CrossColor("Cross Section Color", Color) = (1,1,1,1)
_MainTex("Albedo (RGB)", 2D) = "white" {}
_Glossiness("Smoothness", Range(0,1)) = 0.5
_Metallic("Metallic", Range(0,1)) = 0.0
_PlaneNormal("PlaneNormal",Vector) = (0,1,0,0)
_PlanePosition("PlanePosition",Vector) = (0,0,0,1)
_StencilMask("Stencil Mask", Range(0, 255)) = 255
}
SubShader {
Tags { "RenderType"="Opaque" }
//LOD 200
Stencil
{
Ref [_StencilMask]
CompBack Always
PassBack Replace
CompFront Always
PassFront Zero
}
Cull Back
CGPROGRAM
// Physically based Standard lighting model, and enable shadows on all light types
#pragma surface surf Standard fullforwardshadows
// Use shader model 3.0 target, to get nicer looking lighting
#pragma target 3.0
sampler2D _MainTex;
struct Input {
float2 uv_MainTex;
float3 worldPos;
};
half _Glossiness;
half _Metallic;
fixed4 _Color;
fixed4 _CrossColor;
fixed3 _PlaneNormal;
fixed3 _PlanePosition;
bool checkVisability(fixed3 worldPos)
{
float dotProd1 = dot(worldPos - _PlanePosition, _PlaneNormal);
return dotProd1 > 0 ;
}
void surf(Input IN, inout SurfaceOutputStandard o) {
if (checkVisability(IN.worldPos))discard;
fixed4 c = tex2D(_MainTex, IN.uv_MainTex) * _Color;
o.Albedo = c.rgb;
// Metallic and smoothness come from slider variables
o.Metallic = _Metallic;
o.Smoothness = _Glossiness;
o.Alpha = c.a;
}
ENDCG
Cull Front
CGPROGRAM
#pragma surface surf NoLighting noambient
struct Input {
half2 uv_MainTex;
float3 worldPos;
};
sampler2D _MainTex;
fixed4 _Color;
fixed4 _CrossColor;
fixed3 _PlaneNormal;
fixed3 _PlanePosition;
bool checkVisability(fixed3 worldPos)
{
float dotProd1 = dot(worldPos - _PlanePosition, _PlaneNormal);
return dotProd1 >0 ;
}
fixed4 LightingNoLighting(SurfaceOutput s, fixed3 lightDir, fixed atten)
{
fixed4 c;
c.rgb = s.Albedo;
c.a = s.Alpha;
return c;
}
void surf(Input IN, inout SurfaceOutput o)
{
if (checkVisability(IN.worldPos))discard;
o.Albedo = _CrossColor;
}
ENDCG
}
//FallBack "Diffuse"
}
I tried to start from the double sided shader and add pragma surf surface from the second one at the end of the first PASS like this:
...
//End of the first PASS from the first shader
#include "FastConfigurable.cginc"
#pragma surface surf NoLighting noambient
struct Input {
half2 uv_MainTex;
float3 worldPos;
};
fixed4 _CrossColor;
fixed3 _PlaneNormal;
fixed3 _PlanePosition;
bool checkVisability(fixed3 worldPos)
{
float dotProd1 = dot(worldPos - _PlanePosition, _PlaneNormal);
return dotProd1 > 0;
}
fixed4 LightingNoLighting(SurfaceOutput s, fixed3 lightDir, fixed atten)
{
fixed4 c;
c.rgb = s.Albedo;
c.a = s.Alpha;
return c;
}
void surf(Input IN, inout SurfaceOutput o)
{
if (checkVisability(IN.worldPos))discard;
o.Albedo = _CrossColor;
}
ENDCG
}
Pass
{
Name "BACK"
Tags{ "LightMode" = "ForwardBase" }
Cull Front
ColorMask[_ColorWriteMask]
CGPROGRAM
//Next of the second PASS of the first shader
...
But I am getting the following errors:
Shader Compiler Socket Exception: Terminating shader compiler process
Shader compiler: Preprocess DoubleSidedStandardCrossCut.shader: Internal error communicating with the shader compiler process. Please report a bug including this shader and the editor log.
Shader error in 'DoubleSidedStandardCrossCut': Parse error: syntax error, unexpected $end, expecting TOK_SHADER at line 1
If you have any tip or suggestion, I would really appreciate, thank you!
As often, this boils down to what you want to achieve, and understanding which part of which shader does what you want in your final outcome.
This is not very clear, and I can only make assumptions. It seems you have a given mesh; you wish that it can be (1) carved out based on a Plane, given its position and normal; and want (2) front-facing (F) and back-facing (B) surfaces to have different rendering properties.
Writing multi-pass shaders is often just a shorthand for something you can do with just setup, albeit maybe with a little bit more overhead: Each pass is essentially another draw call, it could just as well be another object.
Options:
In either case 2 and 3, you need 2 materials. They could both use the same shader, or for simplicity you could first author 2 shaders with baked-in properties:
Geometry-1) since it always needs to be covered up by F(ront). (see https://docs.unity3d.com/Manual/SL-SubShaderTags.html)Cull Front flag, and material F uses the Cull Back flag (the default one)checkVisibility(IN.worldPos) to discard pixels that are carved out.On a side note: this needs to be fast since you seem to do VR, so I'd advocate to use the clip() hlsl instruction and have checkVisibility to return a float, to get rid of the conditional branching entirely.