Let's take this one step further. How to cut-up a geometry so it will work in a Poser figure.

Before we even start there are some rules about the body parts in figures that you have to follow. This is probably the most fiddly part of making a figure.

#1 The only parts that can share a common border are parents and children.

#2 Sibling body parts (left collar and right collar) can not share a border.

#3 Grand parents can't share a border with grand children.

#4 A polygon can not be in multiple groups.

#5 Every polygon must be in a group.

#6 Polygon group must be contiguous. (no islands)

#7 Save at every step of the way. A lot of these steps can't be un-done.

This poor donkey came through support recently and I though it was a good example of how to make a Poser rig. The imported figure basically falls apart when posed. If you look at the groups it becomes obvious.

This particular import managed to break pretty much every rule. The "chest" borders 4 of it's grand parents. That 4-corners connection in the middle of the neck. That's 4 segments of the neck so that's never going to work.

OK so how should it be?

In some case you can fix the groups by adding and removing a few polygons in the setup room. Not this case it's just too scrambled up. So we'll need a group it manually.

Import the OBJ for the figure.

Open the group tool.

Delete all the groups.

Now click [New Group] and type the name of the first group. "hip" this will become the name of the body part.

Might as well learn Poser's weird body part naming conventions. There are several body parts with weird internal names. You can see this by looking at the internal names of any figure. And yes the "Shldr" and "foreArm" are really spelled that way.

Switch to wireframe view and use one of the side view cameras to select the hip polygons. Use the wire frame view because that allows you to select hidden and back facing polygons.

Be careful to completely surround any body parts what will be a child of the hip (legs and tail)

Now switch to a solid view so your polygon selections will not select the back facing polygons.

Now create the next group, This will be the first appendage. It can only border the hip, it's parent body part.

You're probably thinking you have to super careful so the first tail and hip parts don't over lap. Nope. Select way more for the first group of the tail than you  need

Now on the group tool check the "Show multigrouped faces". The over lap is really obvious now.

But you can't edit the faces in this view. No matter there's a super easy fix. Turn off "Show Multigrouped faces"

Click Remove > Group > hip

now the tail group is perfectly matched to the hip. If you choose "Show Multigrouped faces" now there should be nothing.

Now let's raise the complexity a notch. Let's introduce symmetry. The figure's limb groups should be symmetrical. Here's how to make left and right sides match.

Create a group for "thighs" this group will be temporary.

Add too much so the thighs group over laps the hip then Remove > Group > hip just like the tail.

Now you have both thighs in a group.

Create a new group for each thigh "lThigh" and "rThigh".

On the Group tool select Add > Group > thighs.

Switch to wire frame again and position the camera so you can clearly see the two legs.

Remove the polygons in the opposite leg. ([Ctrl] + Left Mouse will subtract polygons)

Repeat for the opposite leg.

Delete the temp group "Thighs"

Now work your way down each leg creating the appropriate groups, lShin/rShin and lFoot/rFoot.

Periodically you should check Show multigrouped faces to make sure you haven't accidentally double grouped facets.

When you get to the feet we can try an easier way to make symmetry.

Create the groups for both feet. In the left foot add the appropriate polygons.

Select the right foot.

Add > Group > lFoot

Modify > Mirror > +X to -X

Remove > Group > lFoot

Now you have two identical feet.

Use these techniques to group the rest of the figure.

When you think you're done look at both "Show multigrouped faces" and "Show non-grouped faces" Both of these should be completely empty.

If they're not go back and fix the groups so every face is in exactly one group.

Once you have all the body parts grouped, on the group tool choose [Spawn props]

Delete (or hide) the original geometry.

I colored the props so you can clearly see how I grouped this figure.

Now use the Hierarchy editor to sort the spawned props in the order they should be, Just like with the simple prop figure. There's just more parts.

Then [Create New Figure] just like the prop figure.The new figure will be in the Figures > New figures category of the library.

This time you will definitely need to adjust joint centers and weight maps.

Hopefully this will help somebody.