In Transforms module, make the node selector support vtkMRMLNonLinearTransformNode.
On selection of such a node, disable/collapse the "Display & Edit" section. The "Transformed nodes" section would still be available.

Alex - do your recent changes fix this issue?

http://viewvc.slicer.org/viewvc.cgi/Slicer4?view=revision&revision=22874

I was testing this and got a crash (Mac debug build):
Load in the file Libs/MRML/Core/Testing/TestData/helixMask3Labels.nrrd
Model Maker, create new model hierarchy, run
Open General Registration (BRAINS)
Make a new BSpline transform (create new node)
Go to the Data module
Drag the Model_5_5 under Slicer BSpline Transform

Stack trace:

Program received signal EXC_BAD_ACCESS, Could not access memory.
Reason: 13 at address: 0x0000000000000000
0x00000001226d1db3 in typeinfo name for vtkObjectBase ()
(gdb) bt
#0 0x00000001226d1db3 in typeinfo name for vtkObjectBase ()
0000001 0x00000001224bf59c in vtkSubjectHelper::InvokeEvent (this=0x7fbc793a16a0, event=15000, callData=0x7fbc7932ce40, self=0x7fbc793a0980) at /Users/nicole/Slicer4-svn/Slicer-build-debug/VTK/Common/vtkObject.cxx:620
0000002 0x00000001224bfb42 in vtkObject::InvokeEvent (this=0x7fbc793a0980, event=15000, callData=0x7fbc7932ce40) at /Users/nicole/Slicer4-svn/Slicer-build-debug/VTK/Common/vtkObject.cxx:789
0000003 0x0000000111f85415 in vtkMRMLTransformableNode::OnNodeReferenceAdded (this=0x7fbc793a0980, reference=0x7fbc78f38ab0) at vtkMRMLTransformableNode.h:115
0000004 0x0000000111fd2c8d in vtkMRMLDisplayableNode::OnNodeReferenceAdded (this=0x7fbc793a0980, reference=0x7fbc78f38ab0) at vtkMRMLDisplayableNode.h:240
0000005 0x000000011202a4aa in vtkMRMLModelNode::OnNodeReferenceAdded (this=0x7fbc793a0980, reference=0x7fbc78f38ab0) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Core/vtkMRMLModelNode.cxx:599
0000006 0x00000001120f6a24 in vtkMRMLNode::SetAndObserveNthNodeReference (this=0x7fbc793a0980, referenceRole=0x7fbc754b12d0 "transform", n=0, referencedNode=0x7fbc7932ce40, events=0x7fbc793a0da0) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Core/vtkMRMLNode.cxx:1410
0000007 0x00000001120f67a6 in vtkMRMLNode::UpdateNthNodeReference (this=0x7fbc793a0980, reference=0x7fbc78f38ab0, n=0) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Core/vtkMRMLNode.cxx:1123
0000008 0x00000001120f5078 in vtkMRMLNode::SetAndObserveNthNodeReferenceID (this=0x7fbc793a0980, referenceRole=0x1122fee98 "transform", n=0, referencedNodeID=0x7fbc79051a60 "vtkMRMLBSplineTransformNode1", events=0x7fbc793a0da0) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Core/vtkMRMLNode.cxx:1375
0000009 0x00000001120f6f44 in vtkMRMLNode::SetAndObserveNodeReferenceID (this=0x7fbc793a0980, referenceRole=0x1122fee98 "transform", NodeReferenceID=0x7fbc79051a60 "vtkMRMLBSplineTransformNode1", events=0x0) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Core/vtkMRMLNode.cxx:1494
0000010 0x00000001121f3860 in vtkMRMLTransformableNode::SetAndObserveTransformNodeID (this=0x7fbc793a0980, transformNodeID=0x7fbc79051a60 "vtkMRMLBSplineTransformNode1") at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Core/vtkMRMLTransformableNode.cxx:123
0000011 0x000000010b62cd0f in qMRMLSceneTransformModel::reparent (this=0x7fbc793bbd00, node=0x7fbc793a0980, newParent=0x7fbc7932ce40) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Widgets/qMRMLSceneTransformModel.cxx:108
0000012 0x000000010b62382c in qMRMLSceneModel::updateNodeFromItem (this=0x7fbc793bbd00, node=0x7fbc793a0980, item=0x7fbc7bc58420) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Widgets/qMRMLSceneModel.cxx:1047
0000013 0x000000010b622d41 in qMRMLSceneModel::onItemChanged (this=0x7fbc793bbd00, item=0x7fbc7bc58420) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Widgets/qMRMLSceneModel.cxx:1430
0000014 0x000000010b62558e in qMRMLSceneModel::delayedItemChanged (this=0x7fbc793bbd00) at /Users/nicole/Slicer4-svn/Slicer/Libs/MRML/Widgets/qMRMLSceneModel.cxx:1437
0000015 0x000000010b68df16 in qMRMLSceneModel::qt_metacall (this=0x7fbc793bbd00, _c=QMetaObject::InvokeMetaMethod, _id=18, _a=0x7fff54d99ad0) at /Users/nicole/Slicer4-svn/Slicer-build-debug/Slicer-build/Libs/MRML/Widgets/moc_qMRMLSceneModel.cxx:153
0000016 0x000000010b68f0f4 in qMRMLSceneTransformModel::qt_metacall (this=0x7fbc793bbd00, _c=QMetaObject::InvokeMetaMethod, _id=44, _a=0x7fff54d99ad0) at /Users/nicole/Slicer4-svn/Slicer-build-debug/Slicer-build/Libs/MRML/Widgets/moc_qMRMLSceneTransformModel.cxx:64
0000017 0x0000000116001e26 in QMetaObject::activate ()

This looks like a null pointer issue - just creating the transform node apparently doesn't create the transform itself. Probably we should create an identity transform in the constructor.

I was doing this as a quick test since I didn't have a valid bspline transform handy, but yes, my assumption was that an identity transform was created with the node.
There should also be a test for the null pointer case.

This works now, except the remaining two specific issues: 0003614, 0003615

This specific issue has been resolved. The remaining issues with BSpline transforms are mentioned in Andras note above.

Closing resolved issues that have not been updated in more than 3 months.