Vertex Weighting (Skinning)
Download the example killing floor rig here: Example Rig
This file contains a fully rigged and skinned killing floor player character. You can use it to transfer skinning to your character. This character also serves as proportional ref when modeling. Your character must match this characters proportions and pose.
You can use the Skin Wrap modifier to transfer skinning from this character to your new target character. Follow these steps to do so:
1. Import your character into this scene and make sure his pose and proportions match this character.
2. Select your character and add a Skin Wrap modifier from the modifier list.
3. At the top of the modifier panel click Add > then select the existing character meshes. The skin wrap modifier will look at the skinning information on the meshes you selected here. The example scene has a couple different meshes so make sure to select them all.
4. Next Tweak the distance influence number. This is the radius around each vertex on the reference mesh that it will apply weights to on your mesh. You can visualize this by entering sub object mode on the skin wrap modifier and selecting all the verts in the view port. You will see large red spheres around each vertex of your mesh. Change the distance influence number to where the spheres on your mesh encompass the target mesh as close as possible with the spheres being as small as possible.
5. You can test the results by going to the motion tab, hitting the play button the cat window and double clicking on the two layers below the cat motion layer. The cat motion layer has a walk cycle on it that you can preview your skinning. Press stop and the character will go back to its reference pose. You can also rotate the limbs and to test skinning just press undo after so you get back to the bind pose.
6. Press the checkbox "Weight all points"
7. Click convert to skin. This will convert your skinwrap modifier to an actual skin modifier that will export to unreal. Below is a snap shot with highlighted settings mentioned above.
8. Once you've converted to skin, scroll down on the skin modifier list to the Advanced Parameters section and set the bone affect limit setting to 4. This makes sure no single bone can affect more then 4 vertices. This is important for performance in unreal.
9. At this point you can use the skin modifier to tweak your vertex weighting. There are many tutorials for 3ds max skin modifiers available online.