fornite update

8 files changed, 160 insertions, 96 deletions

diff --git a/3ner.cginc b/3ner.cginc
index bac74ad..26b2a3d 100644
--- a/3ner.cginc
+++ b/3ner.cginc
@@ -28,14 +28,14 @@ v2f vert(appdata v) {
 #endif
   o.uv0 = v.uv0;
   o.objPos = v.vertex;
-#if defined(_CUSTOM31_FRAGMENT_NORMALS) || defined(_CUSTOM31_TESSELLATION)
+#if defined(_VERTEX_DEFORMATION_FRAGMENT_NORMALS) || defined(_VERTEX_DEFORMATION_TESSELLATION)
   o.objPos_orig = v.vertex;
 #endif
 
   // Normal and tangent are in object space.
   o.normal = v.normal;
   o.tangent = v.tangent;
-#if !defined(_CUSTOM31_FRAGMENT_NORMALS)
+#if !defined(_VERTEX_DEFORMATION_FRAGMENT_NORMALS)
   deform_normal(o.objPos, o.normal.xyz, o.tangent.xyz);
 #endif
   deform(o.objPos);
@@ -158,7 +158,7 @@ v2f domain(
   o.objPos   = DOMAIN_INTERP(objPos);
 #endif
 
-#if defined(_CUSTOM31_FRAGMENT_NORMALS) || defined(_CUSTOM31_TESSELLATION)
+#if defined(_VERTEX_DEFORMATION_FRAGMENT_NORMALS) || defined(_VERTEX_DEFORMATION_TESSELLATION)
   o.objPos_orig = DOMAIN_INTERP(objPos_orig);
   o.objPos = o.objPos_orig;
   deform(o.objPos);
@@ -189,7 +189,7 @@ void geom(triangle v2f tri_in[3],
   float3 n0 = v0.normal;
   float3 n1 = v1.normal;
   float3 n2 = v2.normal;
-#if defined(_CUSTOM31_FRAGMENT_NORMALS) || defined(_CUSTOM31_TESSELLATION)
+#if defined(_VERTEX_DEFORMATION_FRAGMENT_NORMALS) || defined(_VERTEX_DEFORMATION_TESSELLATION)
   float3 tmp;
   deform_normal(v0.objPos_orig, n0, tmp);
   deform_normal(v1.objPos_orig, n1, tmp);
@@ -218,11 +218,11 @@ void geom(triangle v2f tri_in[3],
 //endex
 
 float4 frag(v2f i, uint facing : SV_IsFrontFace
-#if defined(_CUSTOM31_TUBES)
+#if defined(_VERTEX_DEFORMATION_TUBES)
 , out float depth : SV_DepthLessEqual
 #endif
 ) : SV_Target {
-#if defined(_CUSTOM31_FRAGMENT_NORMALS)
+#if defined(_VERTEX_DEFORMATION_FRAGMENT_NORMALS)
   deform_normal(i.objPos_orig, i.normal, i.tangent.xyz);
 #endif
 
diff --git a/3ner.shader b/3ner.shader
index aad3949..d8c9f56 100644
--- a/3ner.shader
+++ b/3ner.shader
@@ -55,61 +55,71 @@ Shader "yum_food/3ner"
         [HideInInspector] m_end_Geometry_Shader("Geometry Shader", Float) = 0
         //endex
 
-        //ifex _Custom31_Enabled==0
-        [HideInInspector] m_start_Custom31("Custom31", Float) = 0
-          [ThryToggle(_CUSTOM31)] _Custom31_Enabled("Enable", Float) = 0
-          [ThryToggle(_CUSTOM31_FRAGMENT_NORMALS)] _Custom31_Fragment_Normals_Enabled("Fragment normals", Float) = 0
-          [ThryToggle(_CUSTOM31_TESSELLATION)] _Custom31_Tessellation_Enabled("Tesellation support", Float) = 1
-
-          //ifex _Custom31_Tubes_Enabled==0
-          [HideInInspector] m_start_Custom31_Tubes("Tubes", Float) = 0
-            [ThryToggle(_CUSTOM31_TUBES)] _Custom31_Tubes_Enabled("Enable", Float) = 0
-
-            //ifex _Custom31_XZ_Tube_Enabled==0
-            [HideInInspector] m_start_Custom31_XZ_Tube("XZ Tube", Float) = 0
-              [ThryToggle(_CUSTOM31_XZ_TUBE)] _Custom31_XZ_Tube_Enabled("Enable", Float) = 0
+        //ifex _Vertex_Deformation_Enabled==0
+        [HideInInspector] m_start_Vertex_Deformation("Vertex Deformation", Float) = 0
+          [ThryToggle(_VERTEX_DEFORMATION)] _Vertex_Deformation_Enabled("Enable", Float) = 0
+          [ThryToggle(_VERTEX_DEFORMATION_FRAGMENT_NORMALS)] _Vertex_Deformation_Fragment_Normals_Enabled("Fragment normals", Float) = 0
+          [ThryToggle(_VERTEX_DEFORMATION_TESSELLATION)] _Vertex_Deformation_Tessellation_Enabled("Tesellation support", Float) = 1
+
+          //ifex _Vertex_Deformation_Tubes_Enabled==0
+          [HideInInspector] m_start_Vertex_Deformation_Tubes("Tubes", Float) = 0
+            [ThryToggle(_VERTEX_DEFORMATION_TUBES)] _Vertex_Deformation_Tubes_Enabled("Enable", Float) = 0
+
+            //ifex _Vertex_Deformation_XZ_Tube_Enabled==0
+            [HideInInspector] m_start_Vertex_Deformation_XZ_Tube("XZ Tube", Float) = 0
+              [ThryToggle(_VERTEX_DEFORMATION_XZ_TUBE)] _Vertex_Deformation_XZ_Tube_Enabled("Enable", Float) = 0
               // 0.999... limit prevents NaNs which show up at 1.0
-              _Custom31_XZ_Tube_t("t", Range(-1,1)) = 0
-            [HideInInspector] m_end_Custom31_XZ_Tube("XZ Tube", Float) = 0
+              _Vertex_Deformation_XZ_Tube_t("t", Range(-1,1)) = 0
+            [HideInInspector] m_end_Vertex_Deformation_XZ_Tube("XZ Tube", Float) = 0
             //endex
 
-            //ifex _Custom31_YZ_Tube_Enabled==0
-            [HideInInspector] m_start_Custom31_YZ_Tube("YZ Tube", Float) = 0
-              [ThryToggle(_CUSTOM31_YZ_TUBE)] _Custom31_YZ_Tube_Enabled("Enable", Float) = 0
-              _Custom31_YZ_Tube_t("t", Range(-1,1)) = 0
-            [HideInInspector] m_end_Custom31_YZ_Tube("YZ Tube", Float) = 0
+            //ifex _Vertex_Deformation_YZ_Tube_Enabled==0
+            [HideInInspector] m_start_Vertex_Deformation_YZ_Tube("YZ Tube", Float) = 0
+              [ThryToggle(_VERTEX_DEFORMATION_YZ_TUBE)] _Vertex_Deformation_YZ_Tube_Enabled("Enable", Float) = 0
+              _Vertex_Deformation_YZ_Tube_t("t", Range(-1,1)) = 0
+            [HideInInspector] m_end_Vertex_Deformation_YZ_Tube("YZ Tube", Float) = 0
             //endex
 
-            //ifex _Custom31_XY_Tube_Enabled==0
-            [HideInInspector] m_start_Custom31_XY_Tube("XY Tube", Float) = 0
-              [ThryToggle(_CUSTOM31_XY_TUBE)] _Custom31_XY_Tube_Enabled("Enable", Float) = 0
-              _Custom31_XY_Tube_t("t", Range(-1,1)) = 0
-            [HideInInspector] m_end_Custom31_XY_Tube("XY Tube", Float) = 0
+            //ifex _Vertex_Deformation_XY_Tube_Enabled==0
+            [HideInInspector] m_start_Vertex_Deformation_XY_Tube("XY Tube", Float) = 0
+              [ThryToggle(_VERTEX_DEFORMATION_XY_TUBE)] _Vertex_Deformation_XY_Tube_Enabled("Enable", Float) = 0
+              _Vertex_Deformation_XY_Tube_t("t", Range(-1,1)) = 0
+            [HideInInspector] m_end_Vertex_Deformation_XY_Tube("XY Tube", Float) = 0
             //endex
 
-          [HideInInspector] m_end_Custom31_Tubes("Tubes", Float) = 0
+          [HideInInspector] m_end_Vertex_Deformation_Tubes("Tubes", Float) = 0
           //endex
 
-          //ifex _UV_Scroll_Enabled==0
-          [HideInInspector] m_start_UV_Scroll("UV Scroll", Float) = 0
-            [ThryToggle(_UV_SCROLL)] _UV_Scroll_Enabled("Enable", Float) = 0
-            _UV_Scroll_Speed("Speed (u, v, 0, 0)", Vector) = (0, -1, 0, 0)
-          [HideInInspector] m_end_UV_Scroll("UV Scroll", Float) = 0
+          //ifex _Vertex_Deformation_Seal_Enabled==0
+          [HideInInspector] m_start_Vertex_Deformation_Seal("Seal", Float) = 0
+            [ThryToggle(_VERTEX_DEFORMATION_SEAL)] _Vertex_Deformation_Seal_Enabled("Enable", Float) = 0
+            _Vertex_Deformation_Seal_A("A", Range(0,1)) = 0.1
+            _Vertex_Deformation_Seal_k("k", Range(0,3)) = 1
+            _Vertex_Deformation_Seal_t("t", Range(0,1)) = 0.1
+          [HideInInspector] m_end_Vertex_Deformation_Seal("Seal", Float) = 0
           //endex
 
-          //ifex _Marble_Enabled==0
-          [HideInInspector] m_start_Marble("Marble", Float) = 0
-            [ThryToggle(_MARBLE)] _Marble_Enabled("Enable", Float) = 0
-            [Gradient] _Marble_U_Ramp("U Ramp", 2D) = "white" {}
-            [Gradient] _Marble_V_Ramp("V Ramp", 2D) = "white" {}
-            [Gradient] _Marble_W_Ramp("W Ramp", 2D) = "white" {}
-            _Marble_Scale("Scale", Vector) = (1, 1, 1, 0)
-            _Marble_Strength("Strength", Float) = 1
-            _Marble_Octaves("Octaves", Range(1, 10)) = 3
-          [HideInInspector] m_end_Marble("Marble", Float) = 0
-          //endex
+        [HideInInspector] m_end_Vertex_Deformation("Vertex Deformation", Float) = 0
+
+        //ifex _UV_Scroll_Enabled==0
+        [HideInInspector] m_start_UV_Scroll("UV Scroll", Float) = 0
+          [ThryToggle(_UV_SCROLL)] _UV_Scroll_Enabled("Enable", Float) = 0
+          _UV_Scroll_Speed("Speed (u, v, 0, 0)", Vector) = (0, -1, 0, 0)
+        [HideInInspector] m_end_UV_Scroll("UV Scroll", Float) = 0
+        //endex
+
+        //ifex _Marble_Enabled==0
+        [HideInInspector] m_start_Marble("Marble", Float) = 0
+          [ThryToggle(_MARBLE)] _Marble_Enabled("Enable", Float) = 0
+          [Gradient] _Marble_U_Ramp("U Ramp", 2D) = "white" {}
+          [Gradient] _Marble_V_Ramp("V Ramp", 2D) = "white" {}
+          [Gradient] _Marble_W_Ramp("W Ramp", 2D) = "white" {}
+          _Marble_Scale("Scale", Vector) = (1, 1, 1, 0)
+          _Marble_Strength("Strength", Float) = 1
+          _Marble_Octaves("Octaves", Range(1, 10)) = 3
+        [HideInInspector] m_end_Marble("Marble", Float) = 0
+        //endex
 
-        [HideInInspector] m_end_Custom31("Custom31", Float) = 0
         //endex
       [HideInInspector] m_end_Gimmicks("Gimmicks", Float) = 0
 
diff --git a/brdf.cginc b/brdf.cginc
index d89558c..8352c08 100644
--- a/brdf.cginc
+++ b/brdf.cginc
@@ -138,7 +138,7 @@ float4 brdf(Pbr pbr, LightData data) {
 
   // Direct
   {
-    float remainder = 1.0f;
+    float3 remainder = 1.0f;
 
 #if defined(_CLEARCOAT)
     float cc_f0 = 0.04f;
@@ -149,7 +149,7 @@ float4 brdf(Pbr pbr, LightData data) {
     float3 direct_specular_cc = DFGcc * data.direct.color * data.direct.NoL_cc * pbr.cc_strength;
     direct_specular_cc = max(0, direct_specular_cc);
     specular += direct_specular_cc;
-    remainder -= Fcc * pbr.cc_strength;
+    remainder = saturate(remainder - direct_specular_cc);
 #endif
 
 #if defined(_CLOTH_SHEEN)
@@ -173,7 +173,7 @@ float4 brdf(Pbr pbr, LightData data) {
     float3 direct_specular = FDG * remainder * data.direct.color * data.direct.NoL * lerp(1.0f, pbr.albedo.xyz, pbr.metallic);
     direct_specular = max(0, direct_specular);
     specular += direct_specular;
-    remainder -= F;
+    remainder = saturate(remainder - direct_specular);
 
     float Fd = Fd_OrenNayar(pbr.roughness, data.common.NoV, data.direct.NoL, data.direct.LoV) / PI;
     float3 direct_diffuse = Fd * remainder * (1.0f - pbr.metallic) * pbr.albedo.xyz * data.direct.color;
@@ -184,7 +184,7 @@ float4 brdf(Pbr pbr, LightData data) {
   // Indirect
 #if defined(FORWARD_BASE_PASS)
   {
-    float remainder = 1.0f;
+    float3 remainder = 1.0f;
     float2 dfg_uv = float2(pbr.roughness, data.common.NoV);
 
 #if defined(_CLEARCOAT)
@@ -192,7 +192,7 @@ float4 brdf(Pbr pbr, LightData data) {
     float Fcc = F_Schlick(data.common.NoV, cc_f0, 1.0f);
     float3 indirect_specular_cc = Fcc * data.indirect.specular_cc * pbr.cc_strength;
     specular += indirect_specular_cc;
-    remainder -= Fcc * pbr.cc_strength;
+    remainder = saturate(remainder - indirect_specular_cc);
 #endif
 
 #if defined(_CLOTH_SHEEN)
diff --git a/features.cginc b/features.cginc
index ce8d07d..5ab9cb6 100644
--- a/features.cginc
+++ b/features.cginc
@@ -23,16 +23,21 @@
 #pragma shader_feature_local _CLOTH_SHEEN
 //endex
 
-//ifex _Custom31_Enabled==0
-#pragma shader_feature_local _CUSTOM31
-#pragma shader_feature_local _CUSTOM31_FRAGMENT_NORMALS
+//ifex _Vertex_Deformation_Enabled==0
+#pragma shader_feature_local _VERTEX_DEFORMATION
+#pragma shader_feature_local _VERTEX_DEFORMATION_FRAGMENT_NORMALS
+#pragma shader_feature_local _VERTEX_DEFORMATION_TESSELLATION
 //endex
 
-//ifex _Custom31_Tubes_Enabled==0
-#pragma shader_feature_local _CUSTOM31_TUBES
-#pragma shader_feature_local _CUSTOM31_XZ_TUBE
-#pragma shader_feature_local _CUSTOM31_YZ_TUBE
-#pragma shader_feature_local _CUSTOM31_XY_TUBE
+//ifex _Vertex_Deformation_Tubes_Enabled==0
+#pragma shader_feature_local _VERTEX_DEFORMATION_TUBES
+#pragma shader_feature_local _VERTEX_DEFORMATION_XZ_TUBE
+#pragma shader_feature_local _VERTEX_DEFORMATION_YZ_TUBE
+#pragma shader_feature_local _VERTEX_DEFORMATION_XY_TUBE
+//endex
+
+//ifex _Vertex_Deformation_Seal_Enabled==0
+#pragma shader_feature_local _VERTEX_DEFORMATION_SEAL
 //endex
 
 //ifex _Unlit==0
diff --git a/globals.cginc b/globals.cginc
index 3ba2e60..c460285 100644
--- a/globals.cginc
+++ b/globals.cginc
@@ -58,15 +58,21 @@ float3 _Cloth_Sheen_Color;
 texture2D _Cloth_Sheen_DFG_LUT;
 #endif  // _CLOTH_SHEEN
 
-#if defined(_CUSTOM31_XY_TUBE)
-float _Custom31_XY_Tube_t;
-#endif  // _CUSTOM31_XY_TUBE
-#if defined(_CUSTOM31_XZ_TUBE)
-float _Custom31_XZ_Tube_t;
-#endif  // _CUSTOM31_XZ_TUBE
-#if defined(_CUSTOM31_YZ_TUBE)
-float _Custom31_YZ_Tube_t;
-#endif  // _CUSTOM31_YZ_TUBE
+#if defined(_VERTEX_DEFORMATION_XY_TUBE)
+float _Vertex_Deformation_XY_Tube_t;
+#endif  // _VERTEX_DEFORMATION_XY_TUBE
+#if defined(_VERTEX_DEFORMATION_XZ_TUBE)
+float _Vertex_Deformation_XZ_Tube_t;
+#endif  // _VERTEX_DEFORMATION_XZ_TUBE
+#if defined(_VERTEX_DEFORMATION_YZ_TUBE)
+float _Vertex_Deformation_YZ_Tube_t;
+#endif  // _VERTEX_DEFORMATION_YZ_TUBE
+
+#if defined(_VERTEX_DEFORMATION_SEAL)
+float _Vertex_Deformation_Seal_A;
+float _Vertex_Deformation_Seal_k;
+float _Vertex_Deformation_Seal_t;
+#endif  // _VERTEX_DEFORMATION_SEAL
 
 #if defined(_UV_SCROLL)
 float2 _UV_Scroll_Speed;
diff --git a/interpolators.cginc b/interpolators.cginc
index f9f389c..842861a 100644
--- a/interpolators.cginc
+++ b/interpolators.cginc
@@ -25,7 +25,7 @@ struct v2f {
   float3 normal      : TEXCOORD4;
   float4 tangent     : TEXCOORD5;
   UNITY_LIGHTING_COORDS(6,7)
-#if defined(_CUSTOM31_FRAGMENT_NORMALS) || defined(_CUSTOM31_TESSELLATION)
+#if defined(_VERTEX_DEFORMATION_FRAGMENT_NORMALS) || defined(_VERTEX_DEFORMATION_TESSELLATION)
   float3 objPos_orig : TEXCOORD8;
 #endif
 
diff --git a/vertex.cginc b/vertex.cginc
index 58c5209..730adfe 100644
--- a/vertex.cginc
+++ b/vertex.cginc
@@ -1,51 +1,67 @@
 #ifndef __VERTEX_INC
 #define __VERTEX_INC
 
-#include "custom31.hlsl"
+#include "vertex_deformation.hlsl"
 
 void deform(inout float3 objPos) {
   float t_eps = 1e-9;
-#if defined(_CUSTOM31_XZ_TUBE)
+#if defined(_VERTEX_DEFORMATION_XZ_TUBE)
   {
-    float t = clamp(_Custom31_XZ_Tube_t, -1+t_eps, 1-t_eps);;
+    float t = clamp(_Vertex_Deformation_XZ_Tube_t, -1+t_eps, 1-t_eps);;
     objPos = plane_to_tube(objPos.xyz, t);
   }
-#endif  // _CUSTOM31_XZ_TUBE
-#if defined(_CUSTOM31_YZ_TUBE)
+#endif  // _VERTEX_DEFORMATION_XZ_TUBE
+#if defined(_VERTEX_DEFORMATION_YZ_TUBE)
   {
-    float t = clamp(_Custom31_YZ_Tube_t, -1+t_eps, 1-t_eps);
+    float t = clamp(_Vertex_Deformation_YZ_Tube_t, -1+t_eps, 1-t_eps);
     objPos = plane_to_tube(objPos.yxz, t);
     objPos = objPos.yxz;
   }
-#endif  // _CUSTOM31_YZ_TUBE
-#if defined(_CUSTOM31_XY_TUBE)
+#endif  // _VERTEX_DEFORMATION_YZ_TUBE
+#if defined(_VERTEX_DEFORMATION_XY_TUBE)
   {
-    float t = clamp(_Custom31_XY_Tube_t, -1+t_eps, 1-t_eps);
+    float t = clamp(_Vertex_Deformation_XY_Tube_t, -1+t_eps, 1-t_eps);
     objPos = plane_to_tube(objPos.xzy, t);
     objPos = objPos.xzy;
   }
-#endif  // _CUSTOM31_XY_TUBE
+#endif  // _VERTEX_DEFORMATION_XY_TUBE
+#if defined(_VERTEX_DEFORMATION_SEAL)
+  {
+    float A = _Vertex_Deformation_Seal_A;
+    float k = _Vertex_Deformation_Seal_k;
+    float t = _Time[3] * _Vertex_Deformation_Seal_t;
+    objPos = seal(objPos.xyz, A, k, t);
+  }
+#endif  // _VERTEX_DEFORMATION_SEAL
 }
 
 void deform_normal(float3 objPos, inout float3 objNorm, inout float3 objTan) {
-#if defined(_CUSTOM31_XZ_TUBE)
+#if defined(_VERTEX_DEFORMATION_XZ_TUBE)
   {
-    float t = _Custom31_XZ_Tube_t;
+    float t = _Vertex_Deformation_XZ_Tube_t;
     plane_to_tube_normal(objPos, objNorm, objTan, t);
   }
-#endif  // _CUSTOM31_XZ_TUBE
-#if defined(_CUSTOM31_YZ_TUBE)
+#endif  // _VERTEX_DEFORMATION_XZ_TUBE
+#if defined(_VERTEX_DEFORMATION_YZ_TUBE)
   {
-    float t = _Custom31_YZ_Tube_t;
+    float t = _Vertex_Deformation_YZ_Tube_t;
     plane_to_tube_normal(objPos.yxz, objNorm.yxz, objTan.yxz, t);
   }
-#endif  // _CUSTOM31_YZ_TUBE
-#if defined(_CUSTOM31_XY_TUBE)
+#endif  // _VERTEX_DEFORMATION_YZ_TUBE
+#if defined(_VERTEX_DEFORMATION_XY_TUBE)
   {
-    float t = _Custom31_XY_Tube_t;
+    float t = _Vertex_Deformation_XY_Tube_t;
     plane_to_tube_normal(objPos.xzy, objNorm.xzy, objTan.xzy, t);
   }
-#endif  // _CUSTOM31_XY_TUBE
+#endif  // _VERTEX_DEFORMATION_XY_TUBE
+#if defined(_VERTEX_DEFORMATION_SEAL)
+  {
+    float A = _Vertex_Deformation_Seal_A;
+    float k = _Vertex_Deformation_Seal_k;
+    float t = _Time[0] * _Vertex_Deformation_Seal_t;
+    seal_normal(objPos, objNorm, objTan, A, k, t);
+  }
+#endif  // _VERTEX_DEFORMATION_SEAL
 }
 
 void propagateObjPos(inout v2f i) {
diff --git a/custom31.slang b/vertex_deformation.slang
index 441daeb..63ce1a4 100644
--- a/custom31.slang
+++ b/vertex_deformation.slang
@@ -4,7 +4,7 @@
 #define PI     3.14159265f
 #define PI_RCP 0.31830988f
 
-// Differentiable absolute value.
+// Differentiable versions of common operators.
 #define dabs(x) length(float2(x, 1e-6))
 #define dlerp(x, y, t) ((x) * (1-t) + (y) * t)
 
@@ -29,8 +29,8 @@
   );                                                      \
   float jac_det = determinant(jacobian);                  \
   float3x3 itjac = inverse(transpose(jacobian), jac_det); \
-  normal = normalize(mul(itjac, normal)) * sign(jac_det); \
-  tangent = normalize(mul(jacobian, tangent))
+  normal = mul(itjac, normal) * sign(jac_det);            \
+  tangent = mul(jacobian, tangent)
 
 // Syntactic sugar - wraps the previous three macros.
 #define R3R3_NORMALS(normal, tangent, fun, ...) \
@@ -39,7 +39,7 @@
   R3R3_DEFORM_NORMAL_AND_TANGENT(normal, tangent)
 
 float3x3 inverse(float3x3 m, float det) {
-  if (abs(det) < 1e-6) {
+  if (abs(det) < 1e-9) {
     return float3x3(
         1,0,0,
         0,1,0,
@@ -71,7 +71,7 @@ public float3 plane_to_tube(float3 xyz, no_diff float t) {
   float z0 = xyz.z;
 
   float theta = x0 * PI;
-  float radius = min(1e3, (1.0f / (t * t))) * sign(t) ;
+  float radius = ((1.0f - z0) / (t * t + 1e-3)) * sign(t);
 
   float x = sin(theta / radius) * radius * PI_RCP;
   // The z0 term here is required to make the jacobian invertible.
@@ -85,5 +85,32 @@ public void plane_to_tube_normal(float3 xyz, inout float3 normal,
   R3R3_NORMALS(normal, tangent, plane_to_tube, t);
 }
 
+[Differentiable]
+public float3 seal(float3 xyz, no_diff float A, no_diff float k, no_diff float t) {
+  float x = xyz.x;
+  float y = xyz.y;
+  float z = xyz.z;
+
+  float x0 = x + sin(y * k) * 0.1;
+  float y0 = y + sin(x * k * 2) * 0.5 + cos(z);
+  float z0 = (z + sin(x * y * k * PI + t) * A) * (1.0 + sin(y * k) * sin(x * k));
+
+  x0 += z0 * 0.1 * sin(z0 * PI + 1.5);
+  y0 += z0 * 0.1 * sin(z0 * PI + 1.5);
+
+  x0 -= 0.0;
+  y0 -= 1.2;
+
+  return float3(
+      x0, y0, z0
+  );
+}
+
+// Deform a normal vector using the inverse transpose of the jacobian.
+public void seal_normal(float3 xyz, inout float3 normal,
+    inout float3 tangent, float A, float k, float t) {
+  R3R3_NORMALS(normal, tangent, seal, A, k, t);
+}
+
 #endif  // __CUSTOM31_INC