20 March, 2011

Removing multiple items from textScrollList

I have started working more with Maya UI and I can see why people get frustrated sometimes with handling UI interaction using mel. For example, there is no function to get an item at a given index.

Deletion of multiple items from a list or an array is always tricky because, while deleting multiple items the indices are updated automatically. One solution is to start deleting at the highest index so that the indices to be deleted later are always unaffected.

Here is the function I wrote for the extended textScrollList class. Python's built-in function to sort a list comes in handy here.

def removeAt(self, inds):
    Remove item(s) at given indices from textScrollList
    @inds: takes a single int or a list of int
    if not isinstance(inds,list):
        inds = [inds]
    # indices should be sorted first into descending order 
    #   so that the indices to be deleted next are unaffected
    for i in inds:

14 March, 2011

Rigenerator Update

I have switched back to rigging related work. I have resumed my work on Rigenerator by analyzing my existing code. It can be very helpful to take a break from the work and revisit it later. I found many ideas to improve and more importantly simplify the logic for Rigenerator. Earlier it was not very bad, but I always felt that the code and logic I had written was a bit twisted and difficult to understand. I have put so many comments in the code, but still I was not satisfactory with the logical structure. So I have gone through the code many times as I kept refining it and simplifying the logic.

The first thing I did was to divide the code into proper modules (which I had to do anyway). While doing so I also kept the UI in mind. This will make plugging the UI process easier. There are some changes in logic for exploring the graph. It will allow more possibilities in conditional gathering of graph nodes. Finally I have moved Rigenerator out of my rigging framework project and it is a tool by itself now.

The major changes are in the graph rule structure. It is much more flexible and easy to follow now. The new rule structure allows the following,
# A value can be a node type or a node name
# Neighbor node(s) can be specified for rule condition
# Also, connection attributes can be specified for the rule
# Any value in the above conditions can use simple regular expression (RegEx.)
# Simple RegEx. can be extended in the future to allow more complicated RegEx. syntax
# Rule conditions can be grouped to force AND operation (all conditions should match)

Since I have made a lot of changes, this also requires for more testing. But I am looking forward to finishing the new algorithm and start testing the results!