When imported through the File menu, an FBX will create a CHOP file for each piece of geometry. There's a checkbox in the dialogue that converts the blend shapes into nulls that feed a Blend Shape SOP for their respective piece of geometry. So the question then is: how do you access blend shapes from the CHOP? Houdini crashes if I try to view the entire spreadsheet of one such CHOP, so I can't even see which channels contain the blend shapes, and am not sure what I'd even do after that.

Maybe others can answer that, but I'd say we need an example of what you are talking about

The FBX import dialogue (File -> Edit -> Filmbox FBX) includes the following options:



If I check the box for "Import Blend Deformers as Blend SOPs" under compatibility options, every piece of geometry imports with a Blend Shape SOP with each blend shape represented by a null.



If that box remains unchecked, a CHOP network is created, with a file CHOP for each piece of geometry, and a corresponding Channel SOP within each piece of geometry's network. The File CHOP and SOP both include "blend" in the file path, like so:

If this doesn't clarify things for you, I don't know how else to put it. In the former scenario, I can easily manipulate blend shapes, while in the latter I either can't or don't yet know how to. Admittedly, there are a lot of things I don't understand about the workflow of fully importing an FBX versus, say, an FBX Character Import SOP. It does seem to me that the File SOP doesn't import blend shapes, regardless of the "blend" in the file path, since the information for the File SOP contains neither blend shape attributes nor the telltale _3d_hidden_primitives primitive group. Here are the options, as I see them:

1) There is a way to access blend shapes through the File CHOPs generated by the FBX import dialogue, and I just don't know how to do it yet
2) 1) is not possible, so I'll need to check the box to convert them into SOPs. I've also tried changing the File SOP to an FBX Skin Import SOP, so that's another option.
3) Importing an FBX through the File menu is an antiquated method with no real use case, and I'm just wasting my time with all of this.

I don't know anything about the FBX stuff itself, but for chops, it might help to:

• Set Houdini to "Update Never"
  
• Dive into CHOPs
  
• In the moiton fx viewer pane, toggle everything off under "options" (these choices are not persistent)
  
• Under graphs -> Graphs per single channel
  
• Make sure only one chop is displayed, (remember, you have to alt-click to exclusively choose the display flag)