Hi,
Can anyone advise if an FBX file from Houdini would carry all necessary info into Nuke for comping?
ie. A fluid sim, or shatter scene exported out as an FBX, then imported into Nuke:
Would I -
a) have the fluid / shatter objects in all their 3D glory inside Nuke?
b) have retained any opacity properties from Houdini to Nuke? ie. Semi transparent fluids, glass etc.
c) have control to texture etc inside Nuke

Thanks in advance.
Chaz

Atm the latest Houdini exports only one flavour of FBX which doesn't carry over camera animation into Nuke(possibly all animation). This is a bug(in Nuke, they know about it). Houdini 11.0.526 is the last build with the old multi-flavour export, and I believe I had tried that and it worked reasonably well. I'm quite suspect of something as complex as a DOPs sim making the journey intact, though. I certainly don't see anything like a fluid sim working, apart from writing out geo's of the surface. Don't expect screaming speeds either. I'm a little unclear what you're expecting from Nuke, however. It does have a pretty nice 3D environment, but it's not close to as full featured as a 3D package…

You can control things like uv, position, some basic shading etc…

Cheers,

J.C.

That's fantastically helpful, thank you very much for the info.

To clarify a little further, I have no current project atm that requires this work flow, but am intrigued as to what the best method of integration is between Houdini and Nuke.

Say I was going to comp a scene in Nuke that required a 3D element (for a random example, a Snow Man, and maybe some snow like particles).
The scene in Nuke (for arguments sake) may also contain an imported camera from a tracking app, so the scene itself is matchmoved.

To get the snow man and said particles into the Nuke comp, would I be best to bring the said camera into Houdini also, sort the lighting etc inside of Houdini and render out maybe an EXR from the said ‘tracked’ camera.

Would an EXR contain all opacity properties? Semi transparency, shimmer, reflections etc?

Many many many thanks in advance.
Chaz

We've struggled with this too. Using plain vanilla FBX, here is what you have to ensure to get vaguely reliable cameras:

* You MUST specify a “take” in the FBX export dialog or Nuke won't like it.
* Specify “export frame range”
* Cam Transform and Rotation should have at least two keyframes, even if it's a still camera
* Any nested transforms (subnets, etc) should be extracted using chops to make a clean cam
* If there are any other issues, be sure the rotation order ends up the same in Nuke and Houdini

We have also tried this and it does work and increases functionality. It has not been thoroughly tested though:

http://www.nukepedia.com/gizmos/python-scripts/import-export/fromhoudini2nuke/ [nukepedia.com]

Ooops, I meant to mention that tool, yeah. It's not bad, it's what I'm using now to move between the packages at the moment. It's a port of a Maya2Nuke tool, I had to hack it a little, but it does the job. Plus, being code it's more transparent than fbx, which is basically a black box from the end user perspective.

As far as the snowflake example, you can render whatever you'd like into exr layers, that ends up being a shading exercise. I have a gizmo I cobbled together which takes a mantra exr containing all the standard PBR direct and indirect layers, assembles them in the final beauty pass by default. In between, I have CC and sometimes blurring settings so you can tweak the diffuse, relflect, emit etc all on the fly. It's pretty handy and quite fast as long as you're outputting zip1 compression on your exrs…

Cheers,

J.C.

Sorry for resurrecting this old horse, but just to let those that were pinched by this fbx issue that today's release(11.0.713) now has the three older fbx export formats back! Haven't had a chance to test yet, but yay!

Cheers,

J.C.