https://marksiwat.tumblr.com/post/615909633626898432/as-requested-by-coffeemugsims-heres-a-simple

As requested by @coffeemugsims​ here’s a simple tutorial on how to frankenmesh. Keep in mind that this is very basic and does not cover UV mapping, cuts, LODs, weight or vertex paint (One tutorial on each topic is linked below), I also recommend checking out this post I made on Basic Blender Knowledge if something’s unclear or confusing. Don’t hesitate to send an ask if you have any questions regarding this tutorial.

The only knowledge this requires is knowing how to make your way around the 3D view. A video tutorial talking about that is here.

I am using Blender v2.70 but this should work with with every version after 2.70

Step-by-step tutorial under the cut.

Assuming you’ve already exported your meshes from Sims 4 Studio and opened one of your meshes in Blender:

KEEP IN MIND TO SAVE EVERY NOW AND AGAIN Ctrl + S (save) or Ctrl + Shift + S (Save as…)

1. I always press 1 on the number tab to get to the front view. More hotkeys here

2. Select layer after layer and delete the unwanted ones to make it easier for the future. Layers with meshparts that we have no interest in will eventually be the end of you.

3. I have now deleted all layers with meshparts that I have no interest as I’ll only use the bottom part of this dress. Go to Edit Mode (Hotkey TAB).

4. In Edit Mode all verices (those dots. The lines between vertices are called edges and the area between the edges is called a face) will be selected by default and to unselect them, press A.

5. Now to select the parts I’m not interest in, I use the box tool (hotkey B). I prefer to use the box tool over the circle tool (hotkey C) now as I want a straight line to it’s easier to join with the top later on.

6. To delete the selected vertices, press X and choose vertices