From 5b8fa0b0aef5d040d1050af8593738b98de31878 Mon Sep 17 00:00:00 2001
From: Noeri Huisman <mrxz@users.noreply.github.com>
Date: Wed, 13 Nov 2024 14:46:09 +0100
Subject: [PATCH] Suppress TANGENT warnings for .vrm files as specification
 indicates that these are expected to be generated upon import

---
 lib/src/base/mesh.dart | 8 +++++++-
 lib/src/errors.dart    | 6 ++++++
 2 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/lib/src/base/mesh.dart b/lib/src/base/mesh.dart
index 2eb7ad9..159d7b2 100644
--- a/lib/src/base/mesh.dart
+++ b/lib/src/base/mesh.dart
@@ -526,7 +526,13 @@ class MeshPrimitive extends GltfProperty {
         } else {
           _material.markAsUsed();
 
-          if (!(hasNormal && hasTangent) && _material.needsTangent) {
+          // Note: VRM files are instructed to not have tangents
+          if (context.isVrm) {
+            if (hasTangent) {
+              context.addIssue(LinkError.vrm1MeshPrimitiveTangents,
+                  name: MATERIAL);
+            }
+          } else if (!(hasNormal && hasTangent) && _material.needsTangent) {
             context.addIssue(
                 _material.canProvideTangent
                     ? LinkError.meshPrimitiveGeneratedTangentSpace
diff --git a/lib/src/errors.dart b/lib/src/errors.dart
index 53665ee..98f1945 100644
--- a/lib/src/errors.dart
+++ b/lib/src/errors.dart
@@ -868,6 +868,12 @@ class LinkError extends IssueType {
       'VRM1_MORPH_TARGET_NODE_WITHOUT_MESH',
       (args) => 'No mesh on node ${args[0]} for morph target bind.');
 
+  static final LinkError vrm1MeshPrimitiveTangents = LinkError._(
+      'VRM1_MESH_PRIMITIVE_TANGENTS',
+      (args) =>
+          'Primitive has TANGENTS but VRM importers are expected to generate them.',
+      Severity.Warning);
+
   LinkError._(String type, ErrorFunction message,
       [Severity severity = Severity.Error])
       : super(type, message, severity);