matrix_out: nesting fix + recursive node

[vicdoval]

fixes matrix_out_mk2 nesting and adds recursiveNode mixin to accept lists of list of matrixes

• Ready for merge.

[summereasy]

I got this error message just after the update.

[vicdoval]

I can't reproduce it, i think there was a period in which the matrix out (mk2) node was producing a wrong output (like a couple of weeks) and if your node is from that time it may complain now , just replace it with a new matrix out and all should be fine

[Durman]

Does not vertices have too much nested levels now?

[vicdoval]

The Matrix node of the example had the Flat Output un-checked

[Durman]

I would not expect to get more nested levels any way. I think list of matrixes should produce plain list of vertices.

[vicdoval]

If [m, m] produces [[v], [v]] (most usual case)
Then [[m,m]] should produce [[[v], [v]]]. Any other output can be generated with socket post-processing

[Durman]

If matrix out can split a matrix into a components than matrix in should be able to merge components into a matrix. Now, I suppose, node tree on the picture below don't work.

[vicdoval]

@Durman I see your point... i will change it then

[summereasy]

I can't reproduce it, i think there was a period in which the matrix out (mk2) node was producing a wrong output (like a couple of weeks) and if your node is from that time it may complain now , just replace it with a new matrix out and all should be fine

Thanks for your quick response!
I'm pretty sure I have the latest version (just had re-download the zip again)
I am not a good programmer though, but as far as I can see, the problem I encountered is from here:

1. The newer version 3 days ago has changed a bit for the input of matrix_out Node:

[removed]  input_M = self.inputs['Matrix'].sv_get()
[added]    input_M = params[0]

2. I printed out 2 different input_M as a test:

• I tried several modes like "Flat/Unwrapped/Wrap" etc
• The original input_M = params[0] can give me correct nest-level of input of Matrix
  But the newer version cannot - it stays at 2-level brackets:

# FLAT MODE
#[NEW VERSION] input_M = params[0] output:
input_M = [[Matrix(((1.0, 0.0, 0.0, 0.0),
        (0.0, 1.0, 0.0, 0.0),
        (0.0, 0.0, 1.0, 0.0),
        (0.0, 0.0, 0.0, 1.0)))]]

#[OLD VERSION] input_M2 = self.inputs['Matrix'].sv_get()
input_M2 = [Matrix(((1.0, 0.0, 0.0, 0.0),
        (0.0, 1.0, 0.0, 0.0),
        (0.0, 0.0, 1.0, 0.0),
        (0.0, 0.0, 0.0, 1.0)))]

• so as the data pass into the for loop I got this wired error message

2021-03-31 08:58:39,157 [ERROR] sverchok.core.update_system: Node Matrix Out had exception: 'list' object has no attribute 'decompose'
Traceback (most recent call last):
  File "/Users/zhaowei/Library/Application Support/Blender/2.92/scripts/addons/sverchok-master/core/update_system.py", line 384, in do_update_general
    node.process()
  File "/Users/zhaowei/Library/Application Support/Blender/2.92/scripts/addons/sverchok-master/utils/nodes_mixins/recursive_nodes.py", line 125, in process
    result = process_matched(params, self.process_data, self.list_match, input_nesting, len(self.outputs))
  File "/Users/zhaowei/Library/Application Support/Blender/2.92/scripts/addons/sverchok-master/utils/sv_itertools.py", line 173, in process_matched
    result = main_func(matching_f(params))
  File "/Users/zhaowei/Library/Application Support/Blender/2.92/scripts/addons/sverchok-master/nodes/matrix/matrix_out_mk2.py", line 126, in process_data
    T, R, S = m.decompose()
AttributeError: 'list' object has no attribute 'decompose'

Since I don't have such experiences in programming, I'm guessing that ...
May this error come from a python version problem?
Or does it come from a system OS>?
My Environment:
OSX - 10.15.7
blender - 2.92 (think python version is 3.7.7)

Maybe the question is stupid but ... Thanks for your help again