Erroneous output handling

[mauigna06]

Hi Ronald, thanks a lot for your work on this great library

I'd like to propose to use this boolean table below to handle different results so they are always valid. I was going to implement this idea replacing current code in this link but after thinking about it, I think it would be better to have this table implemented inside vtkbool:

----------------------------------------------------------------------------------------------------
	result		|	touching		|	operation	|	do what?
----------------------------------------------------------------------------------------------------
	0		|	0			|	union		|	append
	0		|	1			|	union		|	retry
	1		|	0x			|	union		|	nothing else
	1		|	1x			|	union		|	nothing else
----------------------------------------------------------------------------------------------------
	0		|	0			|	intersect	|	nothing else
	0		|	1			|	intersect	|	retry
	1		|	0x			|	intersect	|	nothing else
	1		|	1x			|	intersect	|	nothing else
----------------------------------------------------------------------------------------------------
	0		|	0			|	diffA-B		|	result is A
	0		|	1			|	diffA-B		|	retry
	1		|	0x			|	diffA-B		|	nothing else
	1		|	1x			|	diffA-B		|	nothing else
----------------------------------------------------------------------------------------------------
	0		|	0			|	diffB-A		|	result is B
	0		|	1			|	diffB-A		|	retry
	1		|	0x			|	diffB-A		|	nothing else
	1		|	1x			|	diffB-A		|	nothing else
----------------------------------------------------------------------------------------------------

NOTES:

• "result" says if the OutputPolydata of vtkPolyDataBooleanFilter has more than one point.
• "touching" says if the OutputPolydata of vtkCollisionDetectionFilter (between the two input PolyDatas) has more than one point.
• "operation" is the operationType of the vtkPolyDataBooleanFilter.
• boolean variable "result" is truer than boolean variable "touching". E.g. values with an "x" on the right do not matter
• "do what?" says the output definition.
• "nothing else" means keep default output of the booleanFilter
• "retry" means add a small random translation variation (1e-4mm) to one of the inputMeshes to make the result correct if there was an error, and update the vtkPolyDataBooleanFilter again

Please let me know your thoughts

[mauigna06]

I can implement this if you would review it, please let me know Ronald :)
This would solve problems in the workflow of BoneReconstructionPlanner

[mauigna06]

Hi @zippy84

It would be really useful if this "fix" could be pushed to vtkbool instead of having it on BoneReconstructionPlanner or Slicer. What do you think?

[mauigna06]

Hi @zippy84 :)

I've implemented my proposal:
PerkLab/SlicerSandbox@b2252f5

Please review when you have time :)
It would be great if could make that PR part of vtkbool