How To Get A For Loop To Affect Each Individual Object

Question

folks! My question deals with a Python exercise that I'm currently trying to work out (well, to be more specific, the program is Autodesk Maya, but I'm using Python coding). The exercise involves taking a number of objects (spheres) contained in an array/list, and then using an increment variable to have them move in an offset animation. In other words, I want the first sphere to move, then the next spheres to move in a delayed time, then the next sphere with a more delayed time, etc.

The code that I have is as follows:

    spheres = mc.ls(selection=True)
    count=0

    for i in range(len(spheres)):
        count+=2
        mc.selectKey(spheres)
        mc.keyframe(edit=True, relative=True, timeChange=count)
        print spheres(i)

The spheres are my objects, and as I said, I want the first to move normally in the timeline, then the next sphere to move with a delayed time of two, then the next to move with a delayed time of four, so on and so forth.

Any help with this would be much appreciated.

Thanks, E

Answer 1

You're not actually setting the keyframe on the individual sphere; it looks like you're setting it on all spheres

Your for loop is generally bad form, but also less useful. Try changing it to this:

spheres = mc.ls(selection=True)
count=0

for sphere in spheres:
    count += 2
    mc.selectKey(sphere) # only selecting the one sphere!
    mc.keyframe(edit=True, relative=True, timeChange=count)
    print sphere # no need to look up the element
                 # which by the way should have been [i] not (i)

Output:

The keyframes were all lined up originally, but now offset by two frames each from the previous.

Answer 2

You haven't told us what the problem is, but I have a guess. (If I've guessed wrong, please elaborate your question, and I'll delete my answer.)

Are you getting an exception like this?

TypeError                                 Traceback (most recent call last)
----> 1 print spheres(i)

TypeError: 'list' object is not callable

You claim that you have an "array/list" of spheres. If spheres is a list (or array or almost any other kind of collection) you index it using the [] operator. The () operator is used for function calls, not indexing. You're trying to call that list as if it were a function, passing it i as an argument, instead of trying to access that list as a sequence, getting the ith element.

To fix it:

print spheres[i]