begin roughing out marble gimmick

1 files changed, 16 insertions, 0 deletions

diff --git a/pbr.cginc b/pbr.cginc
index 7167929..156fba2 100644
--- a/pbr.cginc
+++ b/pbr.cginc
@@ -23,12 +23,28 @@ void propagateSmoothness(inout Pbr pbr) {
   pbr.roughness = max(MIN_ROUGHNESS, pbr.roughness_perceptual * pbr.roughness_perceptual);
 }
 
+void apply_marble(float3 world_pos, inout float3 albedo) {
+#if defined(_MARBLE)
+  float3 uvw = world_pos * _Marble_Scale;
+  float noise_r = sin_noise_3d_fbm(uvw + _Time[0],     _Marble_Octaves, 2.0f, _Marble_Strength);
+  float noise_g = sin_noise_3d_fbm(uvw+3.1 + _Time[0], _Marble_Octaves, 2.0f, _Marble_Strength);
+  float noise_b = sin_noise_3d_fbm(uvw+3.7 + _Time[0], _Marble_Octaves, 2.0f, _Marble_Strength);
+
+  float3 r = _Marble_U_Ramp.Sample(linear_repeat_s, float2(noise_r, 0));
+  float3 g = _Marble_V_Ramp.Sample(linear_repeat_s, float2(noise_g, 0));
+  float3 b = _Marble_W_Ramp.Sample(linear_repeat_s, float2(noise_b, 0));
+
+  albedo = r + g + b;
+#endif
+}
+
 Pbr getPbr(v2f i) {
   Pbr pbr = (Pbr) 0;
   pbr.normal = normalize(i.normal);
   pbr.albedo = _Color;
   pbr.smoothness = _Smoothness;
   propagateSmoothness(pbr);
+  apply_marble(i.worldPos, pbr.albedo.xyz);
 
   pbr.metallic = _Metallic;
   return pbr;