Explode a bunch of meshes

explode_meshes.py

import time
from maya.api import OpenMaya
MVector = OpenMaya.MVector


def get_dagnode(mesh):

    sel = OpenMaya.MSelectionList()
    sel.add(mesh)
    return OpenMaya.MFnDagNode(sel.getDagPath(0))


def intersections_exist(dagnodes):

    bounds = [dagnode.boundingBox for dagnode in dagnodes]

    while bounds:
        a = bounds.pop()
        for b in bounds:
            if a.intersects(b):
                return True

    return False


def intersects_with(a, dagnodes):
    
    abounds = a.boundingBox
    for dagnode in dagnodes:
        if a == dagnode:
            continue

        if abounds.intersects(dagnode.boundingBox):
            return True
    
    return False


def explode_meshes(meshes, origin=None, factor=None, iterations=-1):

    origin = origin or MVector(0, 0, 0)
    factor = factor or MVector(1, 1, 1)
    dagnodes = [get_dagnode(mesh) for mesh in meshes]
    vectors = []
    for dagnode in dagnodes:
        v = MVector(dagnode.boundingBox.center - origin)
        v = MVector(*[a*b for a, b in zip(v, factor)])
        vectors.append(v)

    i = 0
    while intersections_exist(dagnodes):

        if iterations > 0 and i > iterations:
            break
        for mesh, dagnode, vector in zip(meshes, dagnodes, vectors):
            if not intersects_with(dagnode, list(dagnodes)):
                continue
            cmds.xform(mesh, ws=True, relative=True, translation=vector)

        cmds.refresh()
        time.sleep(0.01)
        i += 1

if __name__ == '__main__':
    cmds.undoInfo(openChunk=True)
    explode_meshes(
        cmds.ls(sl=True), 
        factor=MVector(1, 0.01, 1),
        iterations=1000)
    cmds.undoInfo(closeChunk=True)

explode_meshes2.py

from operator import itemgetter
from maya.api import OpenMaya

MVector = OpenMaya.MVector


def get_node(mesh):

    sel = OpenMaya.MSelectionList()
    sel.add(mesh)
    return OpenMaya.MFnDagNode(sel.getDagPath(0))


def intersects_with(a, nodes):

    bb = a.boundingBox
    for node in nodes:
        if a == node:
            continue
        if bb.intersects(node.boundingBox):
            return True
    return False


def explode_meshes(meshes, origin=MVector(0, 3, 0), factor=MVector(5, 1, 5)):

    nodes = []
    queue = []

    for mesh in meshes:
        node = get_node(mesh)
        nodes.append(node)
        bb = node.boundingBox
        v = MVector(bb.center - origin).normalize()
        v = MVector(v.x * factor.x, v.y * factor.y, v.z * factor.z)
        area = bb.width * bb.height * bb.depth
        queue.append((mesh, node, v, area))

    queue = sorted(queue, key=itemgetter(3))

    while queue:
        mesh, node, vector, _ = queue.pop()
        while intersects_with(node, nodes):
            cmds.xform(mesh, ws=True, relative=True, translation=vector)


if __name__ == '__main__':
    cmds.undoInfo(openChunk=True)
    explode_meshes(cmds.ls(sl=True))
    cmds.undoInfo(closeChunk=True)