Some of the big speed increases are using the iterators and not having to do a bunch of string operations on dag paths. And the math speedups from using the OpenMaya objects with operators.
Your best bet it to just profile some small tests. You can easily make use of the python `timeit` module to check the difference in speed of operations. On Aug 4, 2012, at 10:53 AM, matt wrote: > Apologies for the crosspost for anyone on maya_he3d, only remembered this > group existed seconds after I posted over there... Have tried to edit and > re-word for you smart people. :) > > Short version: > Would using the python OpenMaya module give big speed gains for selecting > thousands of objects and modifying their attributes? > > Long version: > We have a python based, text based render pass submission tool for lighters > at work. One of its core functions is grabbing whatever geometry is defined > by a lighter, and setting attributes. This sometimes means adding attributes > first (or connecting our custom attribute node), then setting them. > > We're getting into the situation where we have _very_ heavy scenes, with > thousands of objects. Normally our system will process these scenes within a > minute or two per frame, if lighters use wildcards, eg 'set:tree*', that can > jump to maybe 6 mins per frame. Not too bad. > > Things get messy with our alembic style heirachical geo format. It can > contain many sub-objects, which our maya plugin doesn't allow us to list or > search for sub-objects names easily. Thus, if a lighter wildcards to the > sub-object level, eg "set:*|leaves*", the only safe way to do that is to > process every object, then every sub-object, unsetting atts those objects > which AREN'T leaves, and setting attrs on those objects which ARE leaves. > When this happens, processing jumps to 3 hours per frame. Yuck! > > In the short term we're getting lighters to be more careful with wildcards, > in the mid term getting assets collapsed down so they're not so name and > sub-object heavy, and in the long term getting our geo plugin more > inspectable. So that's good. > > I was curious though.... could this be helped in the short(ish) term by > re-writing that part of the code with the OpenMaya module? I recall reading > there's many things which are faster, a few which are slower, and fewer still > which have no OpenMaya equivalent and can only be done in mel/python. I have > a sneaking suspicion one of those slow things was something fundamental like > selection, but I'm hoping I'm wrong. > > Was curious if the basic idea of 'yeah, manipulating hundreds of objects and > their attributes is N times faster with OpenMaya' is worth pursuing. > > -matt > > -- > view archives: http://groups.google.com/group/python_inside_maya > change your subscription settings: > http://groups.google.com/group/python_inside_maya/subscribe -- view archives: http://groups.google.com/group/python_inside_maya change your subscription settings: http://groups.google.com/group/python_inside_maya/subscribe
