c31: Start sketching tangent space raymarcher

5 files changed, 82 insertions, 1 deletions

diff --git a/3ner.shader b/3ner.shader
index 1c3b51a..578db84 100755
--- a/3ner.shader
+++ b/3ner.shader
@@ -932,6 +932,20 @@ Shader "yum_food/3ner"
         [HideInInspector] m_end_Logical_Time("Logical Time", Float) = 0
         //endex
 
+        //ifex _Custom31_World_Enabled==0
+        [HideInInspector] m_start_Custom31_World("C31 World Gimmicks", Float) = 0
+          [ThryToggle(_CUSTOM31_WORLD)] _Custom31_World_Enabled("Enable", Float) = 0
+
+          //ifex _Custom31_World_Hexagons_Enabled==0
+          [HideInInspector] m_start_Custom31_World_Hexagons("Hexagons", Float) = 0
+            [ThryToggle(_CUSTOM31_WORLD_HEXAGONS)] _Custom31_World_Hexagons_Enabled("Enable", Float) = 0
+            _Custom31_World_Hexagons_Scale("Scale", Float) = 1
+          [HideInInspector] m_end_Custom31_World_Hexagons("Hexagons", Float) = 0
+          //endex
+
+        [HideInInspector] m_end_Custom31_World("Custom31 World", Float) = 0
+        //endex
+
         //ifex _Vertex_Deformation_Enabled==0
         [HideInInspector] m_start_Vertex_Deformation("Vertex Deformation", Float) = 0
           [ThryToggle(_VERTEX_DEFORMATION)] _Vertex_Deformation_Enabled("Enable", Float) = 0
diff --git a/custom31.cginc b/custom31.cginc
new file mode 100644
index 0000000..6f29403
--- /dev/null
+++ b/custom31.cginc
@@ -0,0 +1,54 @@
+#ifndef __CUSTOM31_INC
+#define __CUSTOM31_INC
+
+#include "globals.cginc"
+#include "interpolators.cginc"
+
+float map(float3 p) {
+  return length(p) - 0.1;
+}
+
+void apply_custom31_world(v2f i, inout Pbr pbr, inout float3 normal_tangent) {
+#if defined(_CUSTOM31_WORLD)
+  // We will raymarch in (tangent, binormal, normal) coordinates.
+  // Make an expanded homogeneous tbn matrix to support moving back and forth.
+  // This first incarnation moves from world to tangent.
+  float4x4 tbn = float4x4(
+      pbr.tbn[0], 0,
+      pbr.tbn[1], 0,
+      pbr.tbn[2], 0,
+      0, 0, 0,    1);
+  tbn = mul(tbn, unity_WorldToObject);
+
+  float3 ro = mul(tbn, float4(i.worldPos, 1));
+  float3 rd = normalize(mul((float3x3) tbn, i.worldPos - _WorldSpaceCameraPos));
+
+  float d_acc = 0;
+  float d;
+  const float MIN_DIST = 1e-3;
+  const float MAX_DIST = 1;
+  [loop]
+  for (uint ii = 0; ii < 10; ++ii) {
+    float3 p = ro + rd * d_acc;
+    d = map(p);
+    d_acc += d;
+    if (d < MIN_DIST) {
+      break;
+    }
+    if (d > MAX_DIST) {
+      break;
+    }
+  }
+
+  if (d < MIN_DIST) {
+    pbr.albedo.xyz = 1;
+  } else {
+    pbr.albedo.xyz = 0;
+  }
+
+  float3 p = ro + rd * d_acc;
+  p = mul(float4(p, 1), tbn);
+#endif
+}
+
+#endif  // __CUSTOM31_INC
diff --git a/features.cginc b/features.cginc
index 47ee80f..e826c72 100755
--- a/features.cginc
+++ b/features.cginc
@@ -134,6 +134,11 @@
 #pragma shader_feature_local _LOGICAL_TIME
 //endex
 
+//ifex _Custom31_World_Enabled==0
+#pragma shader_feature_local _CUSTOM31_WORLD
+#pragma shader_feature_local _CUSTOM31_WORLD_HEXAGONS
+//endex
+
 //ifex _Ray_Marching_Enabled==0
 #pragma shader_feature_local _RAY_MARCHING
 //endex
diff --git a/globals.cginc b/globals.cginc
index 6974ee0..241bb92 100755
--- a/globals.cginc
+++ b/globals.cginc
@@ -183,6 +183,12 @@ float _Center_Offset_Factor;
 float _Logical_Time;
 #endif  // _LOGICAL_TIME
 
+#if defined(_CUSTOM31_WORLD)
+#if defined(_CUSTOM31_WORLD_HEXAGONS)
+float _Custom31_World_Hexagons_Scale;
+#endif  // _CUSTOM31_WORLD_HEXAGONS
+#endif  // _CUSTOM31_WORLD
+
 float getTime() {
 #if defined(_LOGICAL_TIME)
   return _Logical_Time;
diff --git a/pbr.cginc b/pbr.cginc
index 3e37cea..38fd59b 100755
--- a/pbr.cginc
+++ b/pbr.cginc
@@ -1,9 +1,10 @@
 #ifndef __PBR_INC
 #define __PBR_INC
 
+#include "burley.cginc"
+#include "custom31.cginc"
 #include "data.cginc"
 #include "decal.cginc"
-#include "burley.cginc"
 #include "filamented.cginc"
 #include "instancing.cginc"
 #include "interpolators.cginc"
@@ -284,6 +285,7 @@ Pbr getPbr(v2f i) {
   apply_letter_grid(i, pbr);
   apply_burley_tiling(pbr, normal_tangent);
   apply_triplanar_layers(i.worldPos, i.normal, pbr, normal_tangent);
+  apply_custom31_world(i, pbr, normal_tangent);
 
   applyDecals(i, pbr, normal_tangent);