gay behavior

1 files changed, 79 insertions, 0 deletions

diff --git a/custom31.slang b/custom31.slang
new file mode 100644
index 0000000..4b0e003
--- /dev/null
+++ b/custom31.slang
@@ -0,0 +1,79 @@
+#ifndef __CUSTOM31_INC
+#define __CUSTOM31_INC
+
+#define PI 3.14159265f
+
+float3x3 inverse(float3x3 m) {
+  float det =
+    m._11 * (m._22 * m._33 - m._23 * m._32) -
+    m._12 * (m._21 * m._33 - m._23 * m._31) +
+    m._13 * (m._21 * m._32 - m._22 * m._31);
+
+  if (abs(det) < 1e-6) {
+    return float3x3(
+        1,0,0,
+        0,1,0,
+        0,0,1);
+  }
+
+  float invDet = 1.0f / det;
+  float3x3 inv;
+
+  inv._11 = (m._22 * m._33 - m._23 * m._32) * invDet;
+  inv._12 = (m._13 * m._32 - m._12 * m._33) * invDet;
+  inv._13 = (m._12 * m._23 - m._13 * m._22) * invDet;
+  inv._21 = (m._23 * m._31 - m._21 * m._33) * invDet;
+  inv._22 = (m._11 * m._33 - m._13 * m._31) * invDet;
+  inv._23 = (m._13 * m._21 - m._11 * m._23) * invDet;
+  inv._31 = (m._21 * m._32 - m._22 * m._31) * invDet;
+  inv._32 = (m._31 * m._12 - m._11 * m._32) * invDet;
+  inv._33 = (m._11 * m._22 - m._12 * m._21) * invDet;
+
+  return inv;
+}
+
+[Differentiable]
+public float3 c31_deform(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 c31_deform_normal(float3 xyz, inout float3 normal, inout float3 tangent, float A, float k, float t) {
+  // Compute jacobian using autodiff applied to basis vectors.
+  DifferentialPair<float3> dp_x = diffPair(xyz, float3(1, 0, 0));
+  DifferentialPair<float3> dp_y = diffPair(xyz, float3(0, 1, 0));
+  DifferentialPair<float3> dp_z = diffPair(xyz, float3(0, 0, 1));
+
+  DifferentialPair<float3> dp_x_out = fwd_diff(c31_deform)(dp_x, A, k, t);
+  DifferentialPair<float3> dp_y_out = fwd_diff(c31_deform)(dp_y, A, k, t);
+  DifferentialPair<float3> dp_z_out = fwd_diff(c31_deform)(dp_z, A, k, t);
+
+  // Transform normal and tangent using jacobian
+  float3x3 jacobian = float3x3(
+    float3(dp_x_out.d.x, dp_y_out.d.x, dp_z_out.d.x),
+    float3(dp_x_out.d.y, dp_y_out.d.y, dp_z_out.d.y),
+    float3(dp_x_out.d.z, dp_y_out.d.z, dp_z_out.d.z)
+  );
+  float3x3 itjac = inverse(transpose(jacobian));
+  normal = normalize(mul(itjac, normal));
+  tangent = normalize(mul(jacobian, tangent));
+}
+
+#endif  // __CUSTOM31_INC
+