Fix crash by adding nullptr check for camera parent and add unit tests

Author: santosg87

README.md

@@ -30,13 +30,15 @@ Installers for MayaUSD can be found [here](https://github.com/Autodesk/maya-usd/
 - 2023
 - 2024
 - 2025
+- 2026
 
 
 ## Plugin Documentation
 + [Getting Started with USD in Maya 2022](https://help.autodesk.com/view/MAYAUL/2022/ENU/?guid=GUID-36CFE2C3-766F-4B00-8464-E94F95E7AF4B)
 + [Getting Started with USD in Maya 2023](https://help.autodesk.com/view/MAYAUL/2023/ENU/?guid=GUID-36CFE2C3-766F-4B00-8464-E94F95E7AF4B)
 + [Getting Started with USD in Maya 2024](https://help.autodesk.com/view/MAYAUL/2024/ENU/?guid=GUID-36CFE2C3-766F-4B00-8464-E94F95E7AF4B)
 + [Getting Started with USD in Maya 2025](https://help.autodesk.com/view/MAYAUL/2025/ENU/?guid=GUID-36CFE2C3-766F-4B00-8464-E94F95E7AF4B)
++ [Getting Started with USD in Maya 2026](https://help.autodesk.com/view/MAYAUL/2026/ENU/?guid=GUID-36CFE2C3-766F-4B00-8464-E94F95E7AF4B)
 
 ## Building
 Everything needed to build maya-usd is provided in the form of source and a devkit that needs to be installed.  Unit tests are provided for all projects and can be optionally built and executed using google tests. Full details on how to build and test maya-usd can be found in [BUILD.md](doc/build.md)

lib/mayaUsd/ufe/MayaUsdObject3d.cpp

@@ -73,7 +73,7 @@ bool MayaUsdObject3d::visibility() const
             // check if the parent is visible
             auto parentItem = Ufe::Hierarchy::createItem(parentPath);
             auto parentObject3d = Ufe::Object3d::object3d(parentItem);
-            if (!parentObject3d->visibility()) {
+            if (parentObject3d && !parentObject3d->visibility()) {
                 return false;
             }
             parentPath = parentPath.pop();

lib/usdUfe/ufe/UsdCamera.cpp

@@ -497,7 +497,7 @@ bool UsdCamera::computedVisibility() const
             // check if the parent is visible
             auto parentItem = Ufe::Hierarchy::createItem(parentPath);
             auto parentObject3d = Ufe::Object3d::object3d(parentItem);
-            if (!parentObject3d->visibility()) {
+            if (parentObject3d && !parentObject3d->visibility()) {
                 return false;
             }
             parentPath = parentPath.pop();

test/lib/mayaUsd/render/vp2RenderDelegate/VP2RenderDelegateCamerasTest/baseline/RenderCameras_invisibile.png

@@ -26,6 +26,8 @@
 
 from maya import cmds
 
+from pxr import Usd
+
 import unittest
 import ufe
 import os
@@ -117,12 +119,33 @@ def _RunTest(self):
         cmds.currentTime(4)
         self.assertSnapshotClose('%s_animation.png' % (self._testName))
 
+        # test camera creation and visibility
+        self._TestUsdCameraCreationAndVisibility()
+
     def _GetSceneItem(self, mayaPathString, usdPathString):
         mayaPathSegment = mayaUtils.createUfePathSegment(mayaPathString)
         usdPathSegment = usdUtils.createUfePathSegment(usdPathString)
         ufePath = ufe.Path([mayaPathSegment, usdPathSegment])
         ufeItem = ufe.Hierarchy.createItem(ufePath)
         return ufeItem
+    
+    def _TestUsdCameraCreationAndVisibility(self):
+        usdFilePath = cmds.internalVar(utd=1) + '/testCamera.usda'
+        stage = Usd.Stage.CreateNew(usdFilePath)
+        # Create camera under a def
+        scope = stage.DefinePrim('/parent', 'Scope')
+        defPrim = stage.DefinePrim('/cam', '')
+        camera = stage.DefinePrim('/parent/cam/camera1', 'Camera')
+        stage.GetRootLayer().Save()
+        proxyShape = cmds.createNode('mayaUsdProxyShape')
+        cmds.setAttr('mayaUsdProxyShape1.filePath', usdFilePath, type='string')
+        ufeItem = ufeUtils.createItem('|mayaUsdProxy1|mayaUsdProxyShape1,/parent')
+        object3d = ufe.Object3d.object3d(ufeItem)
+        object3d.setVisibility(False)
+        self.assertSnapshotClose('%s_invisibile.png' % (self._testName))
+        object3d.setVisibility(True)
+        self.assertSnapshotClose('%s_visibile.png' % (self._testName))
+
 
     @unittest.skipUnless(mayaUtils.mayaMajorVersion() > 2025, 'Requires Maya fixes only available after Maya 2025.')
     def testCameras(self):