I posted this on Steam too, because I had the Steam version but ran into this problem immediately and had to get it refunded. So this is something that isn't a problem in Modo or Maya by default, but apparently with Houdini it's a problem.

I'm taking a mocapped looped animation sequence from UE4 and bringing just the skeleton and animation data into Houdini for manipulation. But when I try and export it - something I couldn't do in Apprentice and so couldn't find out until I bought it - it's missing frames. That means that in the animation I've got a skip where it loops. It loops fine in Houdini, but as soon as I export it back to Unreal, there's missing animations.

I've found out that by default Houdini does some weird things when importing FBX animations:

- it doesn't start FBX animations at 0, it starts them at 1, so I have to manually set the animation slider to start at 0, revealing a missing frame.
- I have to manually set the FPS rate of the import to 30fps and override scene frame rates, otherwise I don't get the 24 frames in this particular animation, I get either the default 240 or I get 19.

I can mitigate it by adding a frame in UE4, but that only reduces the skipping, it doesn't give me a clean loop. I tried so many settings, both import and export, to get it to work, but it doesn't, it always results in the same skipping. FBX animations are an essential part of my pipeline, and these are just standard animations rigged to the regular Unreal skeleton that, as I said, work with both Maya and Modo without issues.

I really like Houdini, and I'd really like to get to grips with procedural work because I think it has the potential to save so much time, but FBX support is a dealbreaker.

Anyone have any idea what's happening here? Am I missing something?

I'm pretty sure I figured this out. Apparently Houdini's FBX import doesn't care about the distinction between FBX frame rates and keys, and all it really cares about is keys (which are frames in UE4). So instead of importing at x fps and preserving y keyframes (30fps/145 keyframes) it's actually importing that number of keyframes and that's why the loops are truncated.

The solution is to import into Houdini, overriding FBX frame rate to the value that you see in the UE4 animation preview, and overriding scene frame range. In this case the mocap animation sequence from UE4 was 189.13 frames, so I imported into Houdini at 189 FPS, and it exported back to be the exact length with no skips in the sequence.

I'm pretty sure this wouldn't be an issue if I were creating the animations in Houdini. But all my motion is based off the mocaps, which have a lot of keyframes, so although Maya and Modo handled them perfectly, Houdini needed some work.

And now I can do some actual work…