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MENOZ

Bones Animation

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hi.

in other programs the bone system is usually driven by handles.

what is the method in houdini? it's better to control my bones using external controllers/handles, or animate directly the bones???

thanks

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just use whatever you like...it wont matter...

one nice thing about Houdini's bones is that they are real geometry...so you can replace them with anything you want...like a proxy version of your character....

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Well, depending on the use of IK and the complexity of your rig, you may need to be animating control objects.

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oh..yeah for sure...I should have pointed out that I was talking about FK...which is what I thought menoz was talking about

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since houdini's approach to things is quite different from other packages, my question was if houdini is different in setup\animating the bones.

so i NEED controllers? if i don't use controllers (for FK animation), what kind of problems can occur?

yes in IK i need a handle.. i have to study houdini better and make more "focused" question :)

thanks

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for FK you don't need controlers....selecting and rotating the bones themselves is just fine

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for FK you don't need controlers....selecting and rotating the bones themselves is just fine

are you guys talking about Houdini's FK system, or just rotating of bones with nothing on them?

If you not talking about Houdini FK system would it be wise yo use controllers for FK?

-andy

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oh sorry...

we're talking about just rotating bones...which is what everyone else calls FK...Houdini calls it noK...or whatever

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We mean just no IK at all. I'm not really sure who uses Houdini's special FK setup.

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mostly weirdos.....

hehe im a weirdo :P

You guys dont use Houdini's special FK? I thought you would love it arctor, never having to worry about gimbal lock and not sitting down with an animator to fix his scene :).

for those who dont know Houdini's special FK is instead of rotating the bones you translate them, i think its alot easier and you can read translation data alot easier than rotation.

has anyone used it? hope it doesnt get scraped.

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for those who dont know Houdini's special FK is instead of rotating the bones you translate them, i think its alot easier and you can read translation data alot easier than rotation.

We should probably rename it and call it "per bone IK" instead. That would ease the confusion. It's probably better for mocap where you can use the null's as joint positions (without rotation information) and you have per frame data.

The problem with using it for hand animation is that it suffers from the same disadvantage as regular IK on bone chains, it's harder to get smooth moving arcs.

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The problem with using it for hand animation is that it suffers from the same disadvantage as regular IK on bone chains, it's harder to get smooth moving arcs.

I can imagine, ive been getting into rigging recently simply because i want to animate but i want to have the most freedom and that take work :). It depends on how you animate i guess, if you doing stuff with a few keys as posible or something that is more like animated feature film lstuff where you animating on 1's.

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If you just want to animate, then maybe you should just use the autorig for your character rather than trying to do your own rig. And if you're starting, you probably don't want to be doing straight ahead animation on 1's? ;)

I'm not an animator so take all this with a grain of salt. :) From what I've seen, it seems that the ideal way is to make use of IK/FK blending. You use IK when you need to lock down to a specific position like the legs while walking or the hand while pulling on a door knob. For any free flowing action, it's easier to use FK. However, I don't think I've seen the ideal IK/FK hybrid system yet. The problem with IK/FK is managing the transitions. So I guess it depends on your action. If you have lots of such transitions, it might not be worth it to constantly do the switching.

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If you just want to animate, then maybe you should just use the autorig for your character rather than trying to do your own rig. And if you're starting, you probably don't want to be doing straight ahead animation on 1's? ;)

hehe, no way i would animate like that, even when i did 2d and claymation it was more pose to pose. Its only when refining that everything is eventually on 1's, im used to animating on 2's, has a bit more of a punch to it, and when i tried 1's it did look a little bit swimmy, but you get used to it and you can really nail down timing and motion. I still play with F-curves before i get to that point though :P.

I did a few animations in Maya, and you dont naturally get nice arcs when using IK, but when you refine you can get there it just takes a bit more work, work i dont mind :P.

I'm not an animator so take all this with a grain of salt. :) From what I've seen, it seems that the ideal way is to make use of IK/FK blending. You use IK when you need to lock down to a specific position like the legs while walking or the hand while pulling on a door knob. For any free flowing action, it's easier to use FK. However, I don't think I've seen the ideal IK/FK hybrid system yet. The problem with IK/FK is managing the transitions. So I guess it depends on your action. If you have lots of such transitions, it might not be worth it to constantly do the switching.

Ive seen some really cool setups in Maya, im sure it can be done well in Houdini, like you say the transitions is the key, but you wouldnt swtich in the middle of a particular move/gesture, you have to pick your moments to move in and move out, the main issue for me is whenever i hav use FK/IK switching is you have to keep track of everything going on in the curve editor. Cuz usually in maya they tend to be two different rigs that make up the FK and IK.

Oh and for the moment, i want to learn the hard way of riggin before i try the easy way, plus i dont know that much about adding limbs and removing fingers, and having tails etc.

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ok... now i come with a new question...

say i'mparentig my bones to nulls controllers to avoid gimbal lock...

so i animate one axis on the null, and other two on the bone... or wathever...

i want to be able to rotate both controllers in a single handle, OR find a way to not switch by selecting controllers. a solution for this could be the Display persistent handle. but.. it's persistent! it create some confusion in the scene, expecially when ive got more than one handle...

any solutions?

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How does that avoid gimbal lock?

If you must do this, I've provided an example. Unfortunately, it requires many advanced concepts:

- Creating an HDA with only the appropriate parameters promoted

- Creating a custom transform handle for the HDA and binding it with the right parameters

- Promoting invisible transform and rotation orders for the handle

- Turning off the pick flags on the objects inside so that the subnet handle gets used

handmade_null.hip

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mmm sorry.. but i think i don't understand...

in the file if i try to rotate the displayed null i still have the gimbal lock..

should i do the list of things you wrote? :huh:

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in the file if i try to rotate the displayed null i still have the gimbal lock..

It doesn't. Hence my question, "How does that avoid gimbal lock?". All I did in that file was do what you described: "i want to be able to rotate both controllers in a single handle"

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