Hello guys,

I need your help. I have a quest for my school and I don´t know how to do one thing.
I have an animation in Autodesk Motion Builder in FBX format. I need this animation import in Houdini. When I try to import it, there is only the skelet and model without the animation. What can I do? How can I import whole file with animation too? Please help

You should be able to import an animated FBX file into Houdini - our importer should support it. Here's a few things to check:

1) Ideally, make sure that Motion Builder is using FBX SDK 2009.3 to export the file. Sometimes different versions cause incompatibilities.

2) If you would like to, you can also attach the file here and I can take a look at what is going wrong. Please make sure the file is in ASCII FBX format, not binary.

If nothing is moving at all, though, my first thought would be that animation simply did not get exported to the file to begin with.

Me too I'm having terrible issues with fbx import. Animations change or disappear completely.

Without an example file, it's impossible for me to say what exactly is going wrong from a simple statement “animation doesn't import”. Please attach a sample FBX file, exported in ASCII mode, that is causing problems in Houdini and I will take a look at it to see what is happening.

Oleg, I'd send you a file but I haven't been able to isolate the problem and replicate reliably. The hip file I have now is rather too messy to post here. For whatever it is worth this is what I can tell you: I have a scene that

*has more than one merged fbx object (from Maya)
*a collada camera
*2 animated bgeo objects
*a DOP network

The imported fbx object animates OK at first but after scrubbing, playing and manipulating other geometry suddenly the animation of the fbx object lags and its timing changes for no apparent reason. A restart either remedies the problem temporarily, or the animation vanishes completely and the fbx object has to be re-merged.

Thank you for the reply.
This sounds like there is something else going on. If I understood you correctly, you are saying that immediately after you merge all the FBX files into a Houdini scene, everything looks and works correctly. If this is the case, then the FBX importer seems to have done its job properly. It does not run after the initial file load/import.

If the incorrect behaviour begins after other scene manipulations, here's some things to check:

1) Do the actual animation curves on the objects imported from FBX change? If not, this is probably a display/playback problem.

2) Do you happen to have the real-time playback mode on? This is a button next to the time bar in the bottom-right corner of the UI with a tiny clock on it. If it's pressed, Houdini will try to play the animation back in real time, even if this means skipping frames. This may lead to lag and unexpected visual results in the viewport, especially with DOPs.

3) If you're doing DOPs, the playback will most likely lag anyway. Most DOPs simulations are rarely solved in real-time, so usually the first time you hit play on the time bar after making a change, it might take some time to compute all the DOP deformations. Once the simulation is done, its results are cached, and the playback will resume at normal rate.

4) Do objects imported from FBX have locked or unlocked File SOPs? If the locked flag is off (no red flag on the nodes is visible), the geometry is read from the FBX when it is needed. There could potentially be something wrong with that, though probably not, given that the problems are with animation.

Sorry for the long list - I'm just trying to isolate the issue a bit more here, and get some simple things out of the way.

Yes, I think initially the FBX exporter did its job.

The changes in animation were not due to lagging playback because they were still present when I stopped at a frame. I also exported the object again as a obj sequence to see what happened and indeed the animation timing was different (total length was OK though).

The FBX had a keyframe every 5 frames.

I worked around it by importing fbx into xsi, export as obj sequence, and then read into Houdini.

I'll watch out for the locked nodes next time, that's something I didn't think of at all.