Hello,
So, I'm trying to rig a character with the spanky new stuff and I find I'm falling flat on my face. The docs have some basic overview type stuff, but no in-depth explanation of what's going on and I'm constantly hitting walls where things explode for reasons I don't understand.
Is there a definitive explanation of how all this fancy stuff works together somewhere? Am I missing something in the docs or a nice tutorial hidden on the website somewhere?
Specifically, while I understand the Kinematics Override None, the Rest and particularly Capture are fuzzy. Rest is just turning off the IK solvers, right? What is Capture doing?? Does it relate to the Pre-transforms and/or the Rest Angles and Bone Length somehow?
Also, what is the bonealigncapture Hscript command actually doing? There is strange new Capture and Deform region stuff, but I only see one Cregion SOP inside the Bone! What's going on there?

Cheers,

Peter B

OK, a few more questions.

There is the Bone Capture Pose stuff in the Deform Region tab of the Capture tab. I see that if I set the Override Pose to On the bone jumps somewhere else entirely, which I guess is fine then I can tediously rotate back to where I want it. How can I just make it match where I had it in the first place?

Again, am I missing docs that explain this stuff? Or is the character stuff still “campfire lore” in the fine Houdini tradition? )

Cheers,

Peter B

OK, making a little progress. So, if I have the Capture pose parameters match the pre-transforms, things work as I would hope. Soooo… is there any way to auto-extract the pre-transform and apply it to the Capture pose parameters? I know I could write one, but unless I'm missing some important workflow thing, this is something people would do a lot, no?

Cheers,

Peter B

What a nightmare! So, I tediously get the bone's Capture, Rest and regular poses aligned nicely. I move to the second bone (child of the first), and I can copy over the rotates OK for the Rest, rest is working fine, but I go to the Capture override and the bone's translates all end up at 0,0,0!! WTF?

Also, I see handle bindings on the Capture transforms, but I can't figure out how to activate them.

Cheers,

Peter B

it's not me fault

I honestly haven't had time to try it out either. It scared me too when I saw the changes… Just have to keep telling myself it isn't hard.. it is just new ( i feel dirty now )

good luck
-k

OK, so in the Capturing the Arm tutorial, it talks about how “a capture pose was created” when the geometry was captured. HOW??? What is going on behind the scenes? This sort of hidden, black box functionality is why I don't want to use other packages, but now I keep running into it in Houdini, to my unending frustration.

Cheers,

Peter B

The capture pose gets set into bone's capture pose parameters. When you use the Capture Geometry tool using the Capture Pose method (default), then it first initializes those capture pose parameters on the bones and then adds a Capture SOP set to use the capture pose.

The capture pose is always in world space (they ignore the parenting hierarchy). This is so that they don't get messed up when you delete bones.

The Align Capture Pose tool is what you can use to match the capture pose and non-capture pose bone parameters. The hscript equivalent of this tool is the bonealigncapture command.

If you have a capture rig that works but goes all wrong when you switch to the Capture Pose (Kin. Override), then it's probably because it was captured using the Capture Frame method instead.

The IK Rest Kinematic override shows the bones with the Rest Angle parameters used for rotation instead. The rest angle parameters are relative to the pre-transform (just like the regular rotate parameters). These parameters are used to determine the rest bone chain for the InverseKin CHOP (IK solver). They don't directly have anything to do with capturing.

Ah, I see. OK thanks Edward, that does help clear up a few things. I'll give that a try and see what I come up with.

Basically, the Align Capture Pose tool copies rest values to the Capture Pose, include worldspace transform?

Cheers,

Peter B

The Align Capture Pose has two modes. It can either copy the current “animating” cregion parameter values to the “capture” cregion parameter values or vice versa. There's a tool parameter to control that.