Is alembic cache worth it ?

wardle2403

So apperntly Ue4 4.13 supports alembic cache animations, I'm not sure what it is but my understanding is It creates a geometry cache of an animation using a skeleton, am i right ?
So I would assume a skeletal animation is more dynamic but uses more memory than the "Alembic cache".
Should I stick to what I know or should I try getting into this cache thing, how much memory does it really save ?

Jerc

The cache method saves vertices animation rather than bones.
You probably want to use this only for stuff that can't be animated at runtime or require a costly physics setup like a building exploding, cables or ropes breaking or a complex cloth simulation.

wardle2403

Jerc said:

The cache method saves vertices animation rather than bones.
You probably want to use this only for stuff that can't be animated at runtime or require a costly physics setup like a building exploding, cables or ropes breaking or a complex cloth simulation.

Ah thanks, cloth is what I had in mind but I was unsure if I understood what this really is.

JedTheKrampus

You can also do stuff like use rigs with non-bone, non-blendshape deformers, like cage or lattice deformers, for a cutscene.

EarthQuake

I would think alembic would have few uses in games at this point. Depending on geometric complexity alembic files can get into the hundreds of MB for just a couple seconds of animation.

We're supporting Alembic for Toolbag 3, but mostly to make it easy for users to export complex rigs, especially those not designed for games, without having to worry about what is supported by FBX. But I'm not sure how practical it would be outside of very special cases for most games, due to the memory and performance constraints.

throttlekitty

wardle2403 said:

Jerc said:

The cache method saves vertices animation rather than bones.
You probably want to use this only for stuff that can't be animated at runtime or require a costly physics setup like a building exploding, cables or ropes breaking or a complex cloth simulation.

Ah thanks, cloth is what I had in mind but I was unsure if I understood what this really is.

Just to chime in, it would be a static cloth animation, not dynamic.

musashidan

It will be useful for simple parametric modifiers like bend, taper, etc. Or even basic animations like a door opening/closing without having to set up a rig.