Hi there,

I'm testing the charcter tools in Houdini with that simple character shipped with it. Bone editing, capturing and weighting tools works great. But I haven't been able to get some deformations the way I want. It seems I need some morphing for joint deformations after rotation of some bones controlled with IK. I see some arm or limbs ops but I couldn't understand the way they work or what they are really there for thanks to non-user friendly help contents (have to appreciate the help system of 3ds max since I'm a Lightwave user).

Could anyone there mention about some approaches for nice deforming solutions with bones? What those arms or legs ops for, or if there is a way for fine controlled joint deformations?

Thanks in advance,
Diya.

The arm, limb, skeleton sops are deprecated as part of the very early Houdini character system.

Some ways to have better character deformations that I can think of off the top of my head:
- Animate your capture regions. I remember talking about this before either here or on the odforce forums. Try doing a search. You can also put expressions on it so that it automatically deform as your bone angle changes (see the “exhelp boneangle” in a textport).
- Add more bones. Note that you can layer them using more Capture/CaptureProximity SOPs and do blending. The object-level character tools support this via the “Capture Geometry” (with Append option) and the “Edit Capture Blends” tools in the viewport.
- Add muscles. Put down an Inflate SOP and read its help. There might also be descriptions of it lurking around in the forums.
- Append an Edit SOP to your Deform SOP. Pipe the input of your Deform SOP into the second input of the Edit SOP. Now pull points using the Edit SOP. Since you supplied it with a second input, those edits will remain relative to the underlying topology so that it should still look right even after you've moved your bones. You can do tricks with this like having a couple of these and using a Blend SOP. In the Blend, turn on “Assume Only Coordinate Changes In Input” for performance.

Thank you very much for your reply again, edward. Looking to my previous posts, you always answered me kindly with your mini-tutorials


Animate your capture regions.

This might not be the solution I'm looking for, I think I need some point deformations. So your 4th advice made more sense to me, but I'm confused with Pipe the input of your Deform SOP into the second input of the Edit Sop I can't understand how to pipe an input of a SOP to another input of a different SOP? And I tried a method in a same manner but because of the lack of my Houdini knowledge I was unsuccesful. If you care to explain this a bit more clearer or kinda step by step manner I'll be very grateful.

Also I couldn't understand your 2nd method about layering bones. I'll do a search and try to dig deeper.

Thanx again so much,
Later.
Diya

Whatever SOP is the input into the Deform SOP, middle-click on its output. Now left click on the second input of the Edit SOP.

For the second method, you can just use the Capture Geometry tool a second (or third, etc) time with your skin and pick bones that have not been captured yet. Use the viewport slider to control the blending of the bone with the previous capture.

Ok, thank you edward for taking your time. I tried but failed. I know the logic behind morphing or repositioning the points via bone angles, but I haven't been able to create the network. I'm even not sure if I did the appending of the Edit SOP correctly but I also I couldn't figure out the way to use the Blend SOP. That's may be because of the lack of my English, I might misunderstood you. :?

Thanks very much again,
Later.

Diya

Hi again,

Searching the previous posts I observed many valuable informations about capturing geometry, blending geomety captures, editing weights with different methods and so on. I also have been able to use ‘boneangle’ expression to return a value that is controlling the length of another bone (and that is much work for a beginner like me). Now I can handle the capturing geometries and editing weights pretty well. But when I'm trying to deform an arm like geometry, I feel the need of pulling some points (Problem might be solved with adding some more bones and appending new captures and blending them but I want somewhat finer controls). I understood the theory of editing points that are driven with bone angles and blending them but I can't create the network in SOPs editor. As far as I see from your previous paragraphs, I try to append an edit SOP to the output of the deform SOP with middle click, and then tie the output line of deform SOP to the second input of the edit SOP. OK, now I can edit points, but blend it what, and how? That's the point I could came so far…

I'd be glad if there is a kind of tutorial similar to this method or if someone could explain me the missing points.

Thanks,
Diya.