Hi, I have a rigged character with blendshapes.
I can play blendshape animation by Character Blend Shapes SOP, and edit by Attribute Expression SOP.

Anyway, I cannot find a way to export these blendshapes to FBX file.

I tried to use ROP FBX Character Output SOP. But I cannot play blendshapes animation with FBX file exported.

I realized that “blendshape_channel” and “blendshape_name” primitive attributes disappear after exporting.

Manual says “The KineFX export nodes preserve all blend shape data.”, but I could not succeed.

https://www.sidefx.com/docs/houdini/character/kinefx/blendshapes.html [www.sidefx.com]

Is there a way to export FBX with blendshapes in KineFX workflow?

Thanks.

Having the same problem. Importing CC3 Characters into Houdini to add vertex colors to replace materials slots, but fbxcharacteroutput dosent seem to save the blendshape attributes and when importing the exported fbx to ue4 no blendshapes appear.

EDIT: Repro -> Export character with blendshapes with fbxcharacteroutput. Then load that fbx with fbxcharacterimport, and there is no blendshape attributes.

I have the same problem. I'm trying to put together a character workflow for my work with Kine Fx, and no blend shapes are included in the export with FBXcharacterOutput. The workaround I found was to export my character with FBXcharacteroutput, and then to re-import it in via the main menu, I then add the blend shapes, and export my character again via the menu. This process is not a great/smooth way to work. If there is any clarification with an easier/smoother workflow I would very much appreciate it. Thanks!

i have same problem.

just doing my part and having the same problem.

Why don't you RFE? Is it not possible to reproduce?

Please try this out in tomorrow's 18.5.415 daily build.

Still no success for me with the 18.5.415 build.

Hi, also having an issue exporting blend shapes. I tried the 18.5.415 build, and it still didn't work. My blend shapes are created in Houdini the old way (pre-KineFX), and I'm trying to export them with the KineFX skeleton. Blend shapes are connected to the Rest Geometry input of the FBXCharacterOutput. All looks good in the viewport, but not in export. Is there any way to force blend shape export, like in the File/Export/FilmboxFBX? Thanks!

Hey Thomas M, could you log a bug with your FBX file for testing?

Sorry, I missed your post too GSanLob, please submit hip files and/or FBX files so that we can examine the failure cases. Unfortunately, there can be lots of edges cases so we can't really help unless we can debug the issue with the problem cases.

Hi Edward, no problem at all, I think my post was actually not visible because it had to be approved by the moderator (1st post). I submitted a bug report on the issue and it has been logged. Thanks!

Thanks for your file, GSanLob! I had missed from your description that you were trying to export pre-KineFX blendshapes which the new ROP FBX Character Output does not handle. In case others run into this as well, I've attached a hip file demonstrating how to create KineFX-style blendshapes from scratch. We plan on adding proper HDAs in the future for this.

PS. These attributes are described in the help page for Character BlendShapes https://www.sidefx.com/docs/houdini/nodes/sop/kinefx--characterblendshapes#attributes [www.sidefx.com]

edward
I've attached a hip file demonstrating how to create KineFX-style blendshapes from scratch. We plan on adding proper HDAs in the future for this.

Thanks Edward - super useful.

I notice this only works with ROP FBX Character Output, using ROP FBX Animation Output does not include the blend channels. I tried copying "clipchannels" into the stream before export but it also failed.

I'm guessing that's not working because this is still somewhat in development? Or is there info from the Rest Geometry it absolutely needs?

Side note - I also tried getting rid of the dots in blendshape_name due to OCD, but fbx export will add that same prefix if you don't do this. So might as well to make round tripping as accurate as possible.

rangi
using ROP FBX Animation Output does not include the blend channels. I tried copying "clipchannels" into the stream before export but it also failed.

Came here to ask exactly that as well!
I'd like to output the rest FBX Character in one file and all of its animations in separate files (including blendshapes)

rangi
I notice this only works with ROP FBX Character Output, using ROP FBX Animation Output does not include the blend channels. I tried copying "clipchannels" into the stream before export but it also failed.

Currently, the blendshape information is encoded via the blendshape_channel and blendshape_name attributes on the rest geometry stream. The "clipchannels" in the animated skeleton stream is intended merely as a way to map the blendshape_channel values into a possibly differently named float attribute. The FBX animation curves that get created here need to be associated with the blendshapes in the FBX file. If we export these channels in the ROP FBX Animation Output node, I think it's only possible if it was given an input FBX file that already had the blendshapes present.

melMass
I'd like to output the rest FBX Character in one file and all of its animations in separate files (including blendshapes)

I'm not sure how that works with FBX. My understanding was that the FBX blendshapes need to be associated with some FBX mesh node. So even if you could output it into separate files, I'm not following how you combine them back?

edward
I'm not sure how that works with FBX. My understanding was that the FBX blendshapes need to be associated with some FBX mesh node. So even if you could output it into separate files, I'm not following how you combine them back?

I think the rest one holds the shapes while the animation one only the channels keys (without any mesh)

melMass
I think the rest one holds the shapes while the animation one only the channels keys (without any mesh)

By "channel keys" do you mean only the animation curves for the blendshape targets? In that case, are the animation curves in the FBX file just free standing without being associated to anything else in the FBX scene? An example of your set up would be helpful here. Or even better, please provide your desired setup as FBX files in an enhancement request (RFE) using your usual support channels or via the Support > Report a Bug/RFE menu above on this website.

edward

melMass
I think the rest one holds the shapes while the animation one only the channels keys (without any mesh)

By "channel keys" do you mean only the animation curves for the blendshape targets? In that case, are the animation curves in the FBX file just free-standing without being associated with anything else in the FBX scene? An example of your setup would be helpful here. Or even better, please provide your desired setup as FBX files in an enhancement request (RFE) using your usual support channels or via the Support > Report a Bug/RFE menu above on this website.

Yes, and I think FBX can be used as a channel/key container only. I might be wrong.
For the time being, I'm writing the data to a custom file that I can parse in all software, Unity, and Houdini now to mimic that behavior.

Working for me now in 18.5.449, while not yet in production build. Just separated the _3d_hidden_primitives and merged back before export. Could now import CC3 to Houdini, combine material slots with vertex colors and export to UE4. Blendshapes appearing to make faces. Thanks for the fix.