diff --git a/servers/rendering_server.cpp b/servers/rendering_server.cpp
index dd3491f62ce..69a5e1ace05 100644
--- a/servers/rendering_server.cpp
+++ b/servers/rendering_server.cpp
@@ -1239,6 +1239,13 @@ Error RenderingServer::mesh_create_surface_data_from_arrays(SurfaceData *r_surfa
 		// Include custom array format type.
 		if (format & (1ULL << (ARRAY_CUSTOM0 + i))) {
 			format |= (RS::ARRAY_FORMAT_CUSTOM_MASK << (RS::ARRAY_FORMAT_CUSTOM_BASE + i * RS::ARRAY_FORMAT_CUSTOM_BITS)) & p_compress_format;
+
+			// If the mesh contains no vertex array, infer the array length from the custom array.
+			if (array_len == 0) {
+				Vector<Variant> custom_array = p_arrays[RS::ARRAY_CUSTOM0 + i];
+				uint32_t factor_reciprocal = _get_vertex_to_custom_array_length_factor(format, RS::ARRAY_CUSTOM0 + i);
+				array_len = custom_array.size() / factor_reciprocal;
+			}
 		}
 	}
 
@@ -1374,6 +1381,31 @@ Error RenderingServer::mesh_create_surface_data_from_arrays(SurfaceData *r_surfa
 	return OK;
 }
 
+int32_t RenderingServer::_get_vertex_to_custom_array_length_factor(uint32_t p_format, int p_array_index) {
+	uint32_t type = (p_format >> (ARRAY_FORMAT_CUSTOM_BASE + ARRAY_FORMAT_CUSTOM_BITS * (p_array_index - RS::ARRAY_CUSTOM0))) & ARRAY_FORMAT_CUSTOM_MASK;
+	switch (type) {
+		case ARRAY_CUSTOM_RGBA8_UNORM:
+		case ARRAY_CUSTOM_RGBA8_SNORM:
+		case ARRAY_CUSTOM_RG_HALF: {
+			return 4;
+		} break;
+		case ARRAY_CUSTOM_RGBA_HALF: {
+			return 8;
+		} break;
+		case ARRAY_CUSTOM_R_FLOAT:
+		case ARRAY_CUSTOM_RG_FLOAT:
+		case ARRAY_CUSTOM_RGB_FLOAT:
+		case ARRAY_CUSTOM_RGBA_FLOAT: {
+			int32_t s = type - ARRAY_CUSTOM_R_FLOAT + 1;
+
+			return s;
+		} break;
+		default: {
+			ERR_FAIL_V_MSG(0, "Invalid custom format type.");
+		}
+	}
+}
+
 void RenderingServer::mesh_add_surface_from_arrays(RID p_mesh, PrimitiveType p_primitive, const Array &p_arrays, const Array &p_blend_shapes, const Dictionary &p_lods, BitField<ArrayFormat> p_compress_format) {
 	SurfaceData sd;
 	Error err = mesh_create_surface_data_from_arrays(&sd, p_primitive, p_arrays, p_blend_shapes, p_lods, p_compress_format);
diff --git a/servers/rendering_server.h b/servers/rendering_server.h
index e15dba43536..f1a02016631 100644
--- a/servers/rendering_server.h
+++ b/servers/rendering_server.h
@@ -388,6 +388,7 @@ class RenderingServer : public Object {
 	/// Returns stride
 	virtual void mesh_surface_make_offsets_from_format(uint64_t p_format, int p_vertex_len, int p_index_len, uint32_t *r_offsets, uint32_t &r_vertex_element_size, uint32_t &r_normal_element_size, uint32_t &r_attrib_element_size, uint32_t &r_skin_element_size) const;
 	virtual Error mesh_create_surface_data_from_arrays(SurfaceData *r_surface_data, PrimitiveType p_primitive, const Array &p_arrays, const Array &p_blend_shapes = Array(), const Dictionary &p_lods = Dictionary(), uint64_t p_compress_format = 0);
+	int32_t _get_vertex_to_custom_array_length_factor(uint32_t p_format, int p_array_index);
 	Array mesh_create_arrays_from_surface_data(const SurfaceData &p_data) const;
 	Array mesh_surface_get_arrays(RID p_mesh, int p_surface) const;
 	TypedArray<Array> mesh_surface_get_blend_shape_arrays(RID p_mesh, int p_surface) const;