Robes:Skinmeshing

From NWN1 Custom Content Guide

Contents 1 A note on Skinmesh 2 Skinmeshing the Robe 2.1 By Vertex 2.2 By Painting 3 Testing

A note on Skinmesh

Now, this is where I stop and tell you a bit about how skinmeshes and bones work:

• There are 2 styles of skinmesh systems, rigid and smooth.
  • Rigid is similar to Half-Life's system. The vertex moves with the bone it is associated with.
  • Smooth allows you to assign a 'weight' of the bone's influence on the vertex, so it can transition between multiple bones.
• The shape of the bone has little bearing on the influence of the bone on the vertex. Aside from the shadow casting proxy, the only real need for bone geometry is the minimum and maximum dimensions of the object as a box. That is used on the initial skinmesh application to determine the area of influence for the bone. Since we'll be adjusting the values by hand anyway, shape has no bearing.
• Having said that, the skin's vertex deformation is dependant on the bone's rotational and transform values from the initial bind (aka the bind pose). You can make the bones a dummy object, and it can still work.

Skinmeshing the Robe

By Vertex

1. Hide all the other objects on the scene except for the object you're skinning and the bones. With the robe selected, apply the Skin modifier to it. You'll then see a panel similar to this:
   Image:Robe09.jpg
   
   
2. Click on Add Bone and pick all the bones we need (everything except feet, neck and head for the main elven chain). The system will automatically assign the weights to the verticies, but there are a couple problems:
   1. It's all over the place - While you can assign values like the strength and falloff, I generally tend to prefer manually adjusting the weights.
   2. Unlike 3D Studio Max's panel, GMax's Skin modifier does not have an advanced option to limit the number of bone influences to 4, which is the limitation of NWN's skinmesh system.
      Image:Robe10.jpg
      
      
3. After the Skin modifier have been assigned, we'll hide the bones to make adjusting the weights easier.
4. Now the fun part - hit the Edit Envelopes button. If your viewport is in Smooth shaded mode, you'll see a nice rainbow effect on the skinmesh, with the first bone on your list, often the chest, since it's displayed by hierarchy and sorted by name (the topmost parents would be chest or pelvis, so chest is first). In wireframe mode, the verticies will be coloured. Red for the strongest influence, blue for a weak one, and no colour for zero influence.
   Image:Robe11.jpg
   
   
5. Go to the Filters section on the Skin modifier panel, and check Vertex (and probably uncheck the other two). You can now select by vertex instead of envelopes. Now select a bone from the list, then the verticies in the mesh and in the Weight Properties panel, assign the Absolute Effect a value from 0.0 (0%) to 1.0 (100%).
6. For me, a good process for redoing the weights is to pick the pelvis, then select EVERY vertex and give it a value of 1.0. Then progress through the bone hierarchy and reassign the weights. Reason being, if you lower the value of one bone influence, the unused influence points gets redistributed among the other bones in the skeleton, making for a very messy skinmesh. But if you start with a parent bone influencing everything, it makes assigning the bones easier as you're just taking away from the pelvis.
   Image:Robe12.jpg
   
   
7. Don't forget to spread the influence along joints (knees, elbows) so there will be a smoother deformation along them:
   Image:Robe13.jpg
   
   
8. Yes it's a slow process, selecting verticies, assigning weights, having to *RE*assign them after touching another area. Luckily you can always unhide the bones and rotate them around to see the skinmesh deform, and adjust the values:
   Image:Robe14.jpg
   
   
9. Continue doing the same for the legs, and then you're done, export the model!

By Painting

Another method for assigning the weights to the skin is using the paintbrush

Testing

1. Edit the parts_robe.2da file to include your robe model.
2. Pad the 2da file and we'll add to line 27 the following:
3. We do this now because we want to test the skin weights before we move onto the next step.

Almost done, on to Part 3: Robes:AutoScaler

---

Main_Page | PC Body Parts And Clothing | Robes | Robes:Skinmeshing