Is it possible to control the vertex color (directly the color or just the intensity of the color) with shapekeys ?
For example I have the “mouth_happy” shapekey set to 0.
When I set it to 1, because it plays with the corners of the mouth, i want the vertex color in this region to become white or to have the intensity to 1.
Why ?
Because this system allows me to have only 2 normal maps and a better optimization in UE4. One standard and one for every expression deformations combined. So if the vertex color only appears when the shapekey is activated i can get better details without using a NM for each one of them.
Unfortunately, I don’t think a shapekey contains vertex colour data. I like your thinking - using a vertex group to fade between two normal maps - as the face distorts it fades between them.
There IS the possibility to have multiple vertex colour layers - In Blender you can fade between these with mix shaders activated by drivers linked you your shape keys… in unreal… I dunno. I don’t know if the FBX format can handle multiple vertex group layers for a start.
There is this addon
which creates a map of which bits of a mesh are compressed and which bits are
… but…
That’s what I was afraid of. I could ask on the unreal’s forum if it would work but they aren’t as fast and friendly as here (when they answer)
What the add-on does is basically what I want to reproduce in ue4.
Maybe instead of vertex color I can use vertex weight, but it’s no more a Blender problem ^^
There is also the edges lenght solution but it seems too complicated for me ahah.
BTW while shapekeys DO transfer - shapekey animation data does not. At least it doesn’t automatically. I’m sure there’s a way to transfer it.
Also - are you aware of Rhubarb lip sync?
There may be a way to import the rhubarb lipsync data into unreal and have it trigger shapekeys. Rhubarb its self exports a list of times in seconds with decimal places and letters for each key.
I made a quick and simple rig with 4 bones controlling shapekeys (mouth corners and eyebrows going up and down).
Here is the result in UE4 :
But as you can see there are not so much details.
I never heard about this, is seems very good ! I will try it but I don’t know if it will fit my needs (it doesn’t use a face rig, more like a “menu rig” but the results seem really great)
For the face animation i was planning to use this method with a DIY mocap helmet (bike helmet and 2 pieces of wood to keep my smartphone always recording my face at the same distance.)
It seems that there are a lot more solutions that I thought
You can use Rhubarb with a face rig… you basically create a pose-lib pose for each mouthshape.
Rhubarb, however, is designed for stopmotion/cell/pixel-art style lipsinc (created for the game Thimbleweed Park)… so it works best for faces that will be 1 of 9 mouth shapes rather than being able to tween between them. It all depends on the style you’re going for. I would rhubarb would work better for a more cartoony look.
I think I have more tests to do with the facial rig
For the details I will add more tris on the head for the main characters and it will solve my problem (not really but it’s the best solution available).
