Parallel Evaluation in Maya 2018+

README.md

An example of parallel evaluation in Maya 2018+

Scenes

1. Independent hierarchies, with parent constraint

Usage

Files prefixed scene* generate nodes suitable for parallelism, profile* contain ways to measure performance. Each snippet of code is meant to be copy/pasted into the Script Editor and run.

1. Run a scene
2. Run a profile

Output

evaluation=off: 107.23 ms
evaluation=parallel: 103.81 ms

profile1.py

"""Incrementing time via `cmds.currentTime`, keeping track of time

Example:
  evaluation=off: 107.23 ms
  evaluation=parallel: 103.81 ms

"""

import timeit
from maya import cmds

def test(name):
    def run():
        cmds.refresh(suspend=True)
        for i in range(start, end):
            cmds.currentTime(i, update=False)
        cmds.refresh(suspend=False)
    times = timeit.repeat(run, number=1, repeat=3)
    best = min(times)
    print("%s: %.2f ms" % (name, best * 1000))

import timeit

# Profile "mode"
cmds.evaluationManager(mode="off")
test("evaluation=off")
cmds.evaluationManager(mode="parallel")
test("evaluation=parallel")

profile2.py

"""Run Maya for X amount of time in each evaluation mode, keeping track of how many frames it drew

This includes viewport refresh, higher numbers are better.

Example:
  evaluation=off: 128 frames
  evaluation=parallel: 146 frames

"""

from maya import cmds
from PySide2 import QtCore

# Setup
cmds.playbackOptions(min=1)
cmds.playbackOptions(max=10 ** 5)
cmds.playbackOptions(maxPlaybackSpeed=0)
cmds.playbackOptions(playbackSpeed=0)

# Parameters
duration = 1000  # Run for this long

def test(name, setup):
    def onDone():
        cmds.play(state=False)
        results.append("%s: %d frames" % (name, cmds.currentTime(query=True)))
    
        # Run next
        try:
            tests.pop(0)()
        except IndexError:
            onFinished()
            
    def onFinished():
        print("")
        for result in results:
            print(result)

    # Run for 1 second
    cmds.currentTime(1)
    setup()
    cmds.play()
    QtCore.QTimer.singleShot(duration, onDone)


results = list()
tests = [
    lambda: test("evaluation=off", setup=lambda: cmds.evaluationManager(mode="off")),
    lambda: test("evaluation=parallel", setup=lambda: cmds.evaluationManager(mode="parallel"))
]
tests.pop(0)()

scene1.py

import random
from maya import cmds

# WARNING: This will wipe your current scene
cmds.file(new=True, force=True)

branches = 4  # Number of independent hierarchies
depth = 100  # Number of children per branch

# Create Scene
for branch in range(branches):
    root = cmds.createNode("transform", name="root%d" % (branch + 1))
    parent = root
    for i in range(depth):
        parent = cmds.createNode("transform", parent=parent)
    cube, _ = cmds.polyCube(name="cube%d" % branch)
    cmds.parentConstraint(parent, cube)

    key = lambda frame, value: cmds.setKeyframe(
        root,
        attribute="translateY",
        value=value,
        time=[frame],
        inTangentType="linear",
        outTangentType="linear",
    )
    
    # Force evaluation on every frame
    key(1, 0), key((10 ** 3) // 2, random.random() * 10), key(10 ** 5, 0)