This patch ports the Gabor noise shader texture node into Geometry
Nodes.

@@ -2040,0 +2077,4 @@
+ * are sampled using a Bernoulli distribution, as shown in Figure (3). By stratified sampling, they
+ * mean a constant number of impulses per cell, so the stratification is the grid itself in that
+ * sense, as described in the supplementary material of the paper. */
+static constexpr int IMPULSES_COUNT = 8;

@@ -2040,0 +2104,4 @@
+ * real part of the phasor, we use the sine part instead, that is, the imaginary part of the
+ * phasor, as suggested by Tavernier's paper in "Section 3.3. Instance stationarity and
+ * normalization", to ensure a zero mean, which should help with normalization. */
+static float2 compute_2d_gabor_kernel(const float2 position,

@@ -2040,0 +2158,4 @@
+ * noise while it is random for isotropic noise. The original Gabor noise paper mentions that the
+ * weights should be uniformly distributed in the [-1, 1] range, however, Tavernier's paper showed
+ * that using a Bernoulli distribution yields better results, so that is what we do. */
+float2 compute_2d_gabor_noise_cell(const float2 cell,

@@ -2040,0 +2257,4 @@
+/* Computes the orientation of the Gabor kernel such that it is constant for anisotropic
+ * noise while it is random for isotropic noise. We randomize in spherical coordinates for a
+ * uniform distribution. */
+float3 compute_3d_orientation(float3 orientation, float isotropy, float4 seed)

@@ -99,0 +142,4 @@
+  void call(const IndexMask &mask, mf::Params params, mf::Context /*context*/) const override
+  {
+    int param = 0;
+    const VArray<float3> &vector = params.readonly_single_input<float3>(param++, "Vector");

@@ -99,0 +154,4 @@
+    MutableSpan<float> r_intensity = params.uninitialized_single_output_if_required<float>(
+        param++, "Intensity");
+
+    if (type_ == SHD_GABOR_TYPE_2D) {

@@ -99,0 +195,4 @@
+{
+  const NodeTexGabor &storage = node_storage(builder.node());
+  builder.construct_and_set_matching_fn<GaborNoiseFunction>(
+      static_cast<NodeGaborType>(storage.type));