This part of the tutorial is basically a retelling of sciguy77's tutorial. The second part will be a retelling (the way I understand it) of...another one of sciguy77's tutorials 🤣
For this part, we will be working with one of the files we saved separately before. Normally I grab the 'LOD1_noMorphs' one to work with, but this time I'm going to work on 'LOD1_withBones' because I made some tiny adjustments to the mesh after assigning the bones. So, I will import the 'LOD1_withBones' file into a new Milkshape project and save it as a Milkshape project called LOD2.
I will also enable Colored Groups to better see the normals later on.
Hit Ctrl-A to select the entire mesh, then go to the Model tab and select the Scale tool.
Selecting the 'Origin' radio button (instead of the previous 'Center of Mass' one), enter 10000 into all X Y and Z boxes and click Scale.
Hit Ctrl-W (or Vertex \ Weld Together) to weld the mesh.
Enlarging the mesh is necessary to avoid welding vertices together, that shouldn't be, simply because they happened to be very close to each other.
Go to Tools \ DirectX Mesh Tools and move the slider to the left. It'll show 0 vertices at first, but if you move it back to the right, it'll show the number of vertices in your mesh - in this case, 3466. A good rule of thumb for LODs is that each has about half the number of vertices of the previous one while still looking decent e.g. if LOD1 has 3466, LOD2 should have around 1800. I'm not trying to be overly precise so my LOD2 ended up having 1823 vertices.
After this, go to Tools \ Model Cleaner and click No on the popup asking if you want to separate the verts.
Once again hit Ctrl-A to select the entire mesh, go back to the Scale tool, and input .0001. We are essentially shrinking the mesh back to its original dimensions.
You will notice your mesh looks something like this:
This is normal! Go to Tools \ Sims2 UniMesh Make Smoothing Groups and wait for the process to complete. Sometimes, with more complicated meshes, you may get a popup saying that the model was too complex for 32 smoothing groups. When this happens, I normally press V (remember the shortcuts in the first part!) and fix the other groups to the best of my ability. You'll see what I mean shortly.
Fortunately, this mesh wasn't too complex, and we're under 32 smoothing groups 😊
Let's move to the Groups tab, this time paying attention to the portion at the bottom of the group panel called 'Smoothing Groups'.
Making sure the Select button is active, click the 2 button underneath it and you will see a portion of your mesh being selected (button 1 has no mesh parts assigned to it), like in the image below:
With this part selected, hit V (Align Normals) and you will see the mesh colored in a smooth yellow. Continue doing the same with the other smoothing groups (clicking buttons and aligning normals) until you get to something like the image to the right:
This is what happens when we try to align normals near seams. It's a relatively simple fix, but it is more time consuming and I'm infinitely happier when it doesn't happen than when it does 😆
Hit Ctrl-D to duplicate this selection (which will be created as a separate layer) and hide the layer with the top (which should be called group_base).
In the image below I rotated the selection so that we are now looking at the back of it, so the inside of the mesh. To the right, you can see a "slice" of vertices that bend towards the back, that I highlighted in both Textured and Wireframe view - this is the problem area that is leading to dark spots if we assign normals automatically.
To fix this issue, we will also have to divide this duplicated selection into two other parts: the "slice" and the rest of it.
To do this, unselect everything and go to the Model tab, with the Select tool active.
This time, in the 'Select Options' section, we will enable the Face button, ticking the 'Ignore Backfaces' and 'By Vertex' options as well.
Now, we are going to select the vertices on the outside of the seam i.e. not those connected to the body of the mesh. The final selection should look like the image on the right. Make sure that you don't select other vertices than those on this "slice"!
After you've finished selecting all the necessary vertices, hit Ctrl-D again and hide the group you just copied the selection from, so that you only see the duplicated "slice".
Switch to Smooth Shaded or Textured view, hit Ctrl-A to select the "slice", and hit V. If you've selected the vertices correctly, there should be no black spots on your "slice".
Hide the "slice" layer and unhide the previously hidden one. Once again, select your "slice", but this time delete it by hitting the Delete key. Then Ctrl-A and hit V again.
Hide this layer, and unhide your 'group_base' layer. Once again, click the smoothing group button that is assigned to the mesh part we just fixed, then hit Delete. We needed to hide the other two layers, otherwise they would also be deleted. After deleting the selection, unhide both other layers, hit Ctrl-A, and click the Regroup button. Everything will once again be a single group, and the dark spots will be gone:
Do the same for the rest of the smoothing groups. This top is particularly annoying and I had to fix not only the front, but also the back and collar.
After you're done, hit Ctrl-A, click the Assign button, then click on the 1 button. Now you have only one smoothing group.
Rename the layer to 'group_base' and export it as 'LOD2_noMorphs'.
Now we basically go through everything we did when assigning bones and generating morphs for LOD1. However, since LODs 2 and 3 don't typically have so many details and are only used by the game when people play on lower detail modes and/or view the sims from far away, I usually don't go through the process of aligning vertices at the seams, and only make sure the morphs are reasonably shaped (not to the exact position, just resembling a human shape 😅).
I usually use LOD1_withBones and LOD1_withMorphs as references for the LOD2 and LOD3 bones and morphs. This comes with the added bonuses of having a very close reference for bones, and not having to use a different reference mesh for the maternity morph 🙂
After we're done assigning bones and creating morphs for LOD2, we will import the final WSO into our TSRW project, under the 'Medium level of detail' section. Remember to also adjust your materials, as we did in Step 7.
For LOD3, repeat the steps we went through to make LOD2.
And finally, let's prepare the top for regular gameplay!