[H6 fix attempt] Make Newton ViewerGL context current before get_frame

source/isaaclab_visualizers/test/conftest.py

@@ -0,0 +1,48 @@
+# Copyright (c) 2022-2026, The Isaac Lab Project Developers (https://github.com/isaac-sim/IsaacLab/blob/main/CONTRIBUTORS.md).
+# All rights reserved.
+#
+# SPDX-License-Identifier: BSD-3-Clause
+
+"""H6 fix attempt: make Newton ViewerGL's GL context current before get_frame().
+
+Newton's ViewerGL.get_frame issues GL calls without first calling
+self._make_current(). If Kit's GLFW context is current at the moment
+get_frame() runs, those GL calls operate on Kit's context where Newton's
+FBO/PBO ids are invalid - the readback returns zeros, the test fails as
+"fully black".
+
+The patch is applied via pytest_collection_modifyitems so Newton is imported
+only AFTER the test file has run AppLauncher (which sets up Kit's pxr
+bindings). Importing Newton at conftest top-level pulls pxr in too early
+and causes a TypeError on Kit 110+ ('No to_python converter for GfVec3f').
+"""
+
+from __future__ import annotations
+
+
+def _patch_viewergl_make_current_before_get_frame():
+    try:
+        from newton._src.viewer.viewer_gl import ViewerGL
+    except ImportError:
+        return
+
+    if getattr(ViewerGL, "_h6_patched", False):
+        return
+
+    original_get_frame = ViewerGL.get_frame
+
+    def patched_get_frame(self, target_image=None, render_ui=False):
+        try:
+            self.renderer._make_current()
+        except Exception as exc:  # noqa: BLE001
+            print(f"[H6] _make_current failed: {exc}", flush=True)
+        return original_get_frame(self, target_image=target_image, render_ui=render_ui)
+
+    ViewerGL.get_frame = patched_get_frame
+    ViewerGL._h6_patched = True
+    print("[H6] ViewerGL.get_frame wrapped with _make_current()", flush=True)
+
+
+def pytest_collection_modifyitems(config, items):  # noqa: ARG001
+    """Hook fires after test files are collected (i.e., after AppLauncher in test files runs)."""
+    _patch_viewergl_make_current_before_get_frame()