Progress Update #52

Nope, couldn'tdo it. I'm gonna need another two weeks after all :p

I was pretty confident last weekbecause I animateda lot of stuff in Maya, but when I started exporting the scenes to Unity I ran into a bunch of problems, and I ended upspending most of my time troubleshooting rather than animating the rest of the episode. Here are some of my issues:

Limited animation playback in Unity: You can only preview one animation controller at a time in Unity. That becomes a big issue when you have multiple characters with different animation clips interacting with each other because the moment you select any other object in the scene the timeline changes, the preview animation stops, and the character pose resets back to the first frame. So you just end up doing a lot of guesswork and switching betweencharacters, and it's a real pain in the ass to animate the camera in a scene where you don't know the exact position of the characters. You do have the option to run the game, pause and then make changes to the scene, which sounds great, but the editor slows down to a crawl and it's very hard to move things around in the viewport, it's not a good way to work. My best solution for this problem is to animate everything together in Maya, including the camera (which has to be parentedto an object) and just exporting everything again into a new FBX. Now I just try to avoid doing any character animation inside Unity if possible.

Texture animation in Unity: I assumed that Unity handled texture animation just like Mayadid, and that was a big mistake. You can't export UV animation from Maya, and you can't directly animate materials in Unity, you can only animate the UV offset and scale of a specific mesh, so even if you have multiple materials assigned to a single object you have no individual control over them, everything gets animated. My solution was to split the characters faces into multiple objects (head, lefteye, right eye, and mouth) which allows me to animate the UVs individually, but it also creates a new problem, I lose the original smooth surface of the face:

And this seems to be a Mayaproblem with the FBX export, it doesn't preserve the smoothing groups of the objects when there's animation data in the FBX file. I tried a lot of different exporting options to solve the problem but the result is always the same. The solution to this problem was to manually replace the mesh renderer of each face object of the animated FBX with the objects of the static FBX, which is a really bad solution because I have to repeat the process every time I need a face animated, it just feels time-consuming and unnecessary. If I start another project with Unity in the future, I'm gonna have to find a better solution for this problem.

Not everything can be exported: You're limited to geometry and joint animation only, that means that any deformers, clusters or animation expressions that you have in your Maya model are lost when exporting to Unity. Even if you're using a standard rig you still have to bake the keyframes into the joints because the constraints and controls are not going to work. But to be fair, I think this is the standard for most game engines, it's not really a Unity problem, Unreal 4 probably works the exact same way. There is a neat solution though, it's a tool used to store scene data called Alembic cache. It goes through all of your animation and it saves the position of all the vertices of your 3D object for each frame. Depending on the polycount of your model it can create a very large file, but you don't have to worry about the joints or any of the deformers anymore because the Alembic cache only saves the geometry. This cache used to be something exclusive to 3D softwareslike Maya or Blender, but the Unity dev team released an Alembic importer/exporter last year, and it's now possible to easily bring these cache files over to Unity. it's a pretty good solution for fluid and cloth simulation, but I'm using it for my animation expression driven rigs and any other effect that uses the Maya deformers.

Despiteall of these problems, I still like Unity (Maya gives me a lot of headaches too). Thingsmight not be as easier as I was hoping, but it still is a pretty good workflow, especially now that I solved some of the problems. It's been two months since I started, most of the animation is done, and this episode is shaping up to be one of my favorites, so I can't complain too much!