Enable texture-based PBR rendering of backplate

Users can now use PBR textures on their custom backplate!

* Update TaSTT.fbx: UV map aspect ratio matches board

2 files changed, 110 insertions, 21 deletions

diff --git a/Shaders/TaSTT_lighting_template.cginc b/Shaders/TaSTT_lighting_template.cginc
index e1798f9..e3b6239 100644
--- a/Shaders/TaSTT_lighting_template.cginc
+++ b/Shaders/TaSTT_lighting_template.cginc
@@ -14,7 +14,7 @@ struct appdata
 struct v2f
 {
   float4 position : SV_POSITION;
-  float2 uv : TEXCOORD0;
+  float4 uv : TEXCOORD0;
   float3 normal : TEXCOORD1;
   float3 worldPos : TEXCOORD2;
 
@@ -23,8 +23,20 @@ struct v2f
   #endif
 };
 
-float Use_Custom_Background;
-sampler2D Custom_Background;
+float BG_Enable;
+sampler2D BG_BaseColor;
+sampler2D BG_NormalMap;
+sampler2D BG_Metallic;
+sampler2D BG_Smoothness;
+sampler2D BG_Emission_Mask;
+float BG_Smoothness_Invert;
+float BG_NormalStrength;
+float3 BG_Emission_Color;
+float4 BG_BaseColor_ST;
+float4 BG_NormalMap_ST;
+float4 BG_Metallic_ST;
+float4 BG_Smoothness_ST;
+float4 BG_Emission_Mask_ST;
 
 float Enable_Dithering;
 
@@ -117,13 +129,14 @@ void getVertexLightColor(inout v2f i)
   #endif
 }
 
-v2f vert (appdata v)
+v2f vert(appdata v)
 {
   v2f o;
   o.position = mul(UNITY_MATRIX_MVP, v.position);
   o.worldPos = mul(unity_ObjectToWorld, v.position);
-  o.uv = 1.0 - v.uv;
   o.normal = UnityObjectToWorldNormal(v.normal);
+  o.uv.xy = TRANSFORM_TEX(v.uv, BG_BaseColor);
+  o.uv.zw = 1.0 - v.uv;
   getVertexLightColor(o);
   return o;
 }
@@ -271,6 +284,8 @@ fixed sq_dist(fixed2 p0, fixed2 p1)
 
 fixed4 effect_squares (v2f i)
 {
+  float2 uv = i.uv.zw;
+  uv.y *= 2;  // Text box has 2:1 aspect ratio
   const fixed time = _Time.y;
 
   #define PI 3.1415926535
@@ -283,7 +298,7 @@ fixed4 effect_squares (v2f i)
   #define NSQ_Y 5.0
 
   // Map uv from [0, 1] to [-.5, .5].
-  fixed2 p = i.uv - 0.5;
+  fixed2 p = uv - 0.5;
   p *= fixed2(NSQ_X, NSQ_Y);
   p = mul(rot, p);
   p -= 0.5;
@@ -367,7 +382,7 @@ UnityLight GetLight(v2f i)
   return light;
 }
 
-UnityIndirect GetIndirect(v2f i, float3 view_dir) {
+UnityIndirect GetIndirect(v2f i, float3 view_dir, float smoothness) {
   UnityIndirect indirect;
   indirect.diffuse = 0;
   indirect.specular = 0;
@@ -380,7 +395,7 @@ UnityIndirect GetIndirect(v2f i, float3 view_dir) {
   indirect.diffuse += max(0, ShadeSH9(float4(i.normal, 1)));
   float3 reflect_dir = reflect(-view_dir, i.normal);
   // There's a nonlinear relationship between mipmap level and roughness.
-  float roughness = 1 - Smoothness;
+  float roughness = 1 - smoothness;
   roughness *= 1.7 - .7 * roughness;
   float3 env_sample = UNITY_SAMPLE_TEXCUBE_LOD(
       unity_SpecCube0,
@@ -392,6 +407,68 @@ UnityIndirect GetIndirect(v2f i, float3 view_dir) {
   return indirect;
 }
 
+void initNormal(inout v2f i)
+{
+  if (BG_Enable) {
+    i.normal = UnpackScaleNormal(
+        tex2Dgrad(BG_NormalMap, i.uv.xy, ddx(i.uv.x), ddy(i.uv.y)),
+        BG_NormalStrength);
+    // Swap Y and Z
+    i.normal = i.normal.xzy;
+  }
+  i.normal = normalize(i.normal);
+}
+
+fixed4 light(v2f i,
+    sampler2D albedo_map,
+    sampler2D normal_map,
+    float normal_str,
+    sampler2D metallic_map,
+    sampler2D smoothness_map,
+    float invert_smoothness,
+    sampler2D emission_mask,
+    float3 emission_color)
+{
+  initNormal(i);
+
+  float2 iddx = ddx(i.uv.x);
+  float2 iddy = ddy(i.uv.y);
+  fixed4 albedo = tex2Dgrad(albedo_map, i.uv, iddx, iddy);
+
+  fixed3 normal = UnpackScaleNormal(
+        tex2Dgrad(normal_map, i.uv.xy, iddx, iddy),
+        normal_str);
+  // Swap Y and Z
+  normal = normal.xzy;
+
+  float3 view_dir = normalize(_WorldSpaceCameraPos - i.worldPos);
+
+  float metallic = tex2Dgrad(metallic_map, i.uv.xy, iddx, iddy);
+
+  float3 specular_tint;
+  float one_minus_reflectivity;
+  albedo.rgb = DiffuseAndSpecularFromMetallic(
+    albedo, metallic, specular_tint, one_minus_reflectivity);
+
+  UnityIndirect indirect_light;
+  indirect_light.diffuse = 0;
+  indirect_light.specular = 0;
+
+  float smoothness = tex2Dgrad(smoothness_map, i.uv.xy, iddx, iddy);
+  if (invert_smoothness) {
+    smoothness = 1 - smoothness;
+  }
+
+  fixed3 emission = tex2Dgrad(emission_mask, i.uv.xy, iddx, iddy) * emission_color;
+
+  fixed3 pbr = UNITY_BRDF_PBS(albedo, specular_tint,
+      one_minus_reflectivity, smoothness,
+      i.normal, view_dir, GetLight(i), GetIndirect(i, view_dir, smoothness)).rgb;
+  pbr.rgb += emission;
+
+  return fixed4(pbr, albedo.a);
+}
+
 fixed4 light(v2f i, fixed4 unlit)
 {
   // Get color in spherical harmonics
@@ -410,7 +487,7 @@ fixed4 light(v2f i, fixed4 unlit)
 
   fixed3 pbr = UNITY_BRDF_PBS(albedo, specular_tint,
       one_minus_reflectivity, Smoothness,
-      i.normal, view_dir, GetLight(i), GetIndirect(i, view_dir)).rgb;
+      i.normal, view_dir, GetLight(i), GetIndirect(i, view_dir, Smoothness)).rgb;
 
   pbr = lerp(pbr.rgb, unlit.rgb, Emissive);
 
@@ -424,10 +501,10 @@ bool f3ltf3(fixed3 a, fixed3 b)
     a[2] < b[2];
 }
 
-fixed4 frag (v2f i) : SV_Target
+fixed4 frag(v2f i) : SV_Target
 {
-  float2 uv = i.uv;
-  i.normal = normalize(i.normal);
+  float2 uv = i.uv.zw;
+  uv.y *= 2;  // Text box has 2:1 aspect ratio
 
   // Derived from github.com/pema99/shader-knowledge (MIT license).
   if (unity_CameraProjection[2][0] != 0.0 ||
@@ -537,14 +614,18 @@ fixed4 frag (v2f i) : SV_Target
   }
   // The edges of each letter cell can be slightly grey due to mip maps.
   // Detect this and shade it as the background.
-  fixed3 grey = fixed3(.1,.1,.1);
+  fixed3 grey = fixed3(.3,.3,.3);
   if (f3ltf3(text.rgb, grey) || discard_text) {
-    if (Use_Custom_Background) {
-      float2 iddx = ddx(uv.x);
-      float2 iddy = ddy(uv.y);
-      return light(
-          i,
-          tex2Dgrad(Custom_Background, uv, iddx, iddy));
+    if (BG_Enable) {
+      return light(i,
+        BG_BaseColor,
+        BG_NormalMap,
+        BG_NormalStrength,
+        BG_Metallic,
+        BG_Smoothness,
+        BG_Smoothness_Invert,
+        BG_Emission_Mask,
+        BG_Emission_Color);
     } else {
       return light(i, Background_Color);
     }
diff --git a/Shaders/TaSTT_template.shader b/Shaders/TaSTT_template.shader
index bf9f53a..e0d436c 100644
--- a/Shaders/TaSTT_template.shader
+++ b/Shaders/TaSTT_template.shader
@@ -19,8 +19,15 @@
 

     [MaterialToggle] Enable_Dithering("Enable font dithering", float) = 1

 

-    [MaterialToggle] Use_Custom_Background("Enable custom background", float) = 0

-    Custom_Background("Custom background", 2D) = "black" {}

+    [MaterialToggle] BG_Enable("Enable custom background", float) = 0

+    BG_BaseColor("Background base color", 2D) = "black" {}

+    [NoScaleOffset] BG_NormalMap ("Background normal map", 2D) = "bump" {}

+    BG_NormalStrength ("Background normal strength", Float) = 1

+    BG_Smoothness("Background smoothness", 2D) = "black" {}

+    [MaterialToggle]BG_Smoothness_Invert("Invert background smoothness", float) = 1

+    BG_Metallic("Background metallic", 2D) = "black" {}

+    BG_Emission_Mask("Background emission mask", 2D) = "black" {}

+    BG_Emission_Color("Background emission color", Color) = (0, 0, 0)

 

     _Font_0x0000_0x1FFF ("_Font 0 (unicode 0x0000 - 0x1FFFF)", 2D) = "white" {}

     _Font_0x2000_0x3FFF ("_Font 1 (unicode 0x2000 - 0x3FFFF)", 2D) = "white" {}

@@ -79,5 +86,6 @@
       ENDCG

     }

   }

+  //CustomEditor "TaSTTShaderGUI"

 }