see how on the body the thigh bone exists pretty far away from where it is on the first dress?on the second dress it is completely absent. That's because those two dresses were shaped differently and meant to behave differently. Since you need to combine them, you also need to make sure they behave the same.
Frankenmeshing may seem like an easy thing to do but it is quite misleading. "easy" is not really a word i'd use to describe any process related to it.
I can give you a basic idea of how you would do it "the maxis way". It would most likely not be enough but at least you would be able to judge if the author of the tutorial is telling you enough
1). delete the geometry that covers the hole. Usually the easiest way is to select its uv island in UV editor (enable sync, find a uv island, select it), but in this case it is not obvious where it is, so you can select it in 3d view. Disable Limit selection to visible, press B, click-and-drag to select the vertex in the middle of that geometry, then Select - Select linked to select the whole thing. Then press Select and choose Faces;
2). Append the other dress in the scene. File - Append, find the file, choose Object, then all or the right meshgroup. Delete the unnecessary meshgroups, rename the right one to Skirt or something;
3). With Skirt selected, switch to Edit mode and delete everything that is not needed. It is easier to do in Uv editor: select the area you need, then invert the selection (Ctrl I);
4). Before you'l start reshaping the skirt, there are a few things you can do to make it easier for yourself.
- Remove doubles. Right now the geometry that covers the hole at the bottom is separated from the rest of the skirt. When you will start moving the skirt, that geometry will not be affected. So you need to join them;
- in this case it is not necessary but in some cases it can make selecting edges easier: select the whole mesh, Mesh - Faces - Tris to quads;
5). Switch to orthographic (NUM5) side (NUM3) view, select the whole mesh with A, press S Y to scale the mesh down along Y axis. Then you can deselect the top edge loop and make the rest smaller or move it. Basically you want the shape to match the rest of the dress. Then switch to the front (NUM1) and adjust some more. And do it from the bottom. You may need to adjust from the side as well after that;
6). Once happy with the overall shape, enable proportional editing and try to adjust the top edge loop to have a similar shape to the bottom of the first dress. Then in UV editor select the top edge loop and straighten it ( S Y 0 ). You can adjust the second one as well.
7). Select the meshgroup that contains the rest of the dress. Select and delete the area of legs that is covered by the skirt;
8). Once done, select everything with A. Shift select the first dress (the meshgroup that has the shirt) and press Ctrl J to join. Move the uv island of the skirt up. You can select the top edge loop of legs and lower it in uv editor to avoid overlapping. For some reason the whole skirt of the first dress is flipped, so you should flip the added uv island as well in a way that aligns with the rest of the dress( select the area, UVs - Mirror - X axis);
9). The first dress is cut up in the skirt area, so you need to select everything and remove doubles. Then you can Alt click on these edge loops and bridge them;
10). Separate the skirt with P - Selection. Append a dress of similar shape, transfer weights and uv_1 from it;
11). Join the separated skirt back with the dress, remove doubles again. Remove doubles ( W - Remove doubles, Merge distance set to 0,0001 ) on both uv maps;
12). Split edges that need to be sharp
Here's the
blend file
