From 8bd5105c8ac5ac8771a40e3bbca52aa480a27eaa Mon Sep 17 00:00:00 2001
From: Vijay Dirisala <techvd@gmail.com>
Date: Mon, 18 May 2026 00:45:58 -0700
Subject: [PATCH] UV data can be indexed in some FBX files. This patch exposes
 the underlying vertex_uv.indices data via uv_indices property.

---
 ufbx/_ufbx.pyx          | 17 +++++++++++++++++
 ufbx/src/ufbx_wrapper.c | 10 ++++++++++
 ufbx/src/ufbx_wrapper.h |  1 +
 3 files changed, 28 insertions(+)

diff --git a/ufbx/_ufbx.pyx b/ufbx/_ufbx.pyx
index 58cd2bc..00cf5f5 100644
--- a/ufbx/_ufbx.pyx
+++ b/ufbx/_ufbx.pyx
@@ -446,6 +446,7 @@ cdef extern from "ufbx_wrapper.h":
     const float* ufbx_wrapper_mesh_get_vertex_bitangents(const ufbx_mesh *mesh, size_t *out_count)
     const float* ufbx_wrapper_mesh_get_vertex_colors(const ufbx_mesh *mesh, size_t *out_count)
     const uint32_t* ufbx_wrapper_mesh_get_indices(const ufbx_mesh *mesh, size_t *out_count)
+    const uint32_t* ufbx_wrapper_mesh_get_uv_indices(const ufbx_mesh *mesh, size_t *out_count)
 
     # Mesh face data
     size_t ufbx_wrapper_mesh_get_face_count(const ufbx_mesh *mesh)
@@ -2482,6 +2483,22 @@ cdef class Mesh(Element):
         shape[0] = <np.npy_intp>count
         return np.PyArray_SimpleNewFromData(1, shape, np.NPY_UINT32, <void*>data)
 
+    @property
+    def uv_indices(self):
+        """UV indices as numpy array (N,)"""
+        if self._scene._closed:
+            raise RuntimeError("Scene is closed")
+
+        cdef size_t count = 0
+        cdef const uint32_t* data = ufbx_wrapper_mesh_get_uv_indices(self._mesh, &count)
+
+        if data == NULL or count == 0:
+            return None
+
+        cdef np.npy_intp shape[1]
+        shape[0] = <np.npy_intp>count
+        return np.PyArray_SimpleNewFromData(1, shape, np.NPY_UINT32, <void*>data)
+
     @property
     def materials(self):
         """Materials used by this mesh"""
diff --git a/ufbx/src/ufbx_wrapper.c b/ufbx/src/ufbx_wrapper.c
index dba25f8..665d940 100644
--- a/ufbx/src/ufbx_wrapper.c
+++ b/ufbx/src/ufbx_wrapper.c
@@ -280,6 +280,16 @@ const uint32_t* ufbx_wrapper_mesh_get_indices(const ufbx_mesh *mesh, size_t *out
     return mesh->vertex_position.indices.data;
 }
 
+const uint32_t* ufbx_wrapper_mesh_get_uv_indices(const ufbx_mesh *mesh, size_t *out_count) {
+    if (!mesh || !mesh->vertex_uv.exists || !out_count) {
+        if (out_count) *out_count = 0;
+        return NULL;
+    }
+
+    *out_count = mesh->vertex_uv.indices.count;
+    return mesh->vertex_uv.indices.data;
+}
+
 // Mesh face data
 size_t ufbx_wrapper_mesh_get_face_count(const ufbx_mesh *mesh) {
     return mesh ? mesh->faces.count : 0;
diff --git a/ufbx/src/ufbx_wrapper.h b/ufbx/src/ufbx_wrapper.h
index 31bace3..908de30 100644
--- a/ufbx/src/ufbx_wrapper.h
+++ b/ufbx/src/ufbx_wrapper.h
@@ -82,6 +82,7 @@ const float* ufbx_wrapper_mesh_get_vertex_tangents(const ufbx_mesh *mesh, size_t
 const float* ufbx_wrapper_mesh_get_vertex_bitangents(const ufbx_mesh *mesh, size_t *out_count);
 const float* ufbx_wrapper_mesh_get_vertex_colors(const ufbx_mesh *mesh, size_t *out_count);
 const uint32_t* ufbx_wrapper_mesh_get_indices(const ufbx_mesh *mesh, size_t *out_count);
+const uint32_t* ufbx_wrapper_mesh_get_uv_indices(const ufbx_mesh *mesh, size_t *out_count);
 
 // Mesh face data
 size_t ufbx_wrapper_mesh_get_face_count(const ufbx_mesh *mesh);