expression little problem

[maks]

Make sure that the expression returns 0 from the bones rest position. In this case you can substract the bones rest rotation like this: [Skeleton_Bone_3: pitch] - ( PitchRestValue * DTOR )
When you apply this to the Null's zpos set the channel modifier to relative (+).

I hope this was clear. :)

[GabrielW]

THX!!! it works great:) i hope that i learn messiah's expressions fast:(:(

[DMack]

GabrielW,
Seriously stick with those expressions....When I started I found them a little daunting (though much much better than any other expression system I've come across) but soon started to absolutely love them. They are fantastic and by far the simplest to learn.

Keep with it, they pay massive dividends later on!

[GabrielW]

Hello Guys
DMack thank you very very much for optimism:)

Its my first character in messiah :D:D:D SORRY FOR STUPID PROBLEMS:(:( :wip:
http://gabrielw.250free.com/WIP/PROBLEM_1.jpg
i have another problem ( i am sure that it very easy. i cant find solution in Messiah DOCUMENT

1. ARM ROTATOR is parented to bone "2".
2. When i move Ik-goal and rotate arm rotator, everything is beautiful but only in 0 frame
3. When i want rotate arm (by arm rotator). arm rotator change position to bone's "2" pivot and don't rotate ARM!!:(:(.Only in all frames excluded frame 0.
4 expresion. i have used this expression too:
--arm_rotator:bank
|_____bone_2:bank


where is the bug?:(:(:(:((:(:(

[maks]

Hi Gabriel,

it's very difficult to understand what you are trying to do here. The "follow" expression in your setup is intriging me, it's purpose is described as follows: "An object will remain a certain distance behind another along a motion path". Is that what you want to do? I think the best way to get help here is to provide scene file that we can look at :)

M.

[My Fault]

Hmmm, looks like you are trying to do an IK/FK system where rotating the Arm Rotator moves the IK goal and when you move the IK goal the rotator matches the position of the bone 2 pivot, correct?

BTW, great looking model!

[maks]

If that's the case then you'll very likely have problems like this. If you want to control the forearm with a control object who's parent is driven by IK, wich controls the forearm bone as well, then your IK solving will get confused.

[GabrielW]

hmm i want create simple ik system with arm rotator here is scene:(:( i dont know what is wrong with it.
it works only in frame 0:(:(

its information for scene:
have created two expresions in follow expresion and direct
follow expresion(ARM_rotator_A) work only in 0 frame , object is changing position to parent pivot
direct(ARM_rotator_B) everything works good but arm rotator change position too!!:(:(its frustrating:(
i think that i have terrible mess here:(

scene (http://gabrielw.250free.com/WIP/PROBLEM.fxs)


SORRY guys:(:( I HAVE CREATED NOW SCENE WITH 3 BONES ik HELPER AND THIS ARM ROTATOR . I HAVE CREATE EXPRESION FOR ROTATOR AND WORKS GOOD:(:(: i dont know why there i have problem .


BIG THX for any HELP!!

[maks]

Ok, I'm still not completely sure what you were trying to achieve, but if it's a simply IK setup while controlling the UpperArm's bank with your control object, then your ARM_rotator_B expression works here. The arm rotator doesn't change position as you described, and there's no reason that it would do so. The Follow expression (ARM_rotator_A) doesn't make any sense here - I don't understand what you were trying to do with it, since it's purpose is, as I quoted above, to make one object follow another along a motion path.

The problem with your IK setup was, that you have some expressions that control the UpperArm, set to solve after IK. To make the IK work here, you should use an IK expression that solves after the other expressions and set it to "after IK" as well, instead of using IK from the Inverse Kinematic tab. I also noticed that your forearm had an offset in its heading channel - this shifts the arm away from the IK goal, because IK is solving exclusively on the pitch channel in messiah (thus 2D IK). Ideally all elements in your IK chain should have no offset on heading and bank.

I attached the modified scene, I hope this helps. :)

[GabrielW]

hieh THX MAKS!!!

i dont know how to explain :(:( (my english is bad:))

all i want is only create two controllers to have arm control.
ONE i have its IK. goal
TWO is a controler who can change arm angle.

Maks this archiwed file have some error:(:( could you place it again here?

"The arm rotator doesn't change position as you described, and there's no reason that it would do so" --- have you check it in animation tab in frames other than frame 0?? :cry:
i will try to understand messiah expresions in few days(if i can):D hihi

[maks]

hieh THX MAKS!!!

i dont know how to explain :(:( (my english is bad:))

all i want is only create two controllers to have arm control.
ONE i have its IK. goal
TWO is a controler who can change arm angle.

Then the setup does what you want. :)

Maks this archiwed file have some error:(:( could you place it again here?

What kind of error? The file downloads and opens fine here.

"The arm rotator doesn't change position as you described, and there's no reason that it would do so" --- have you check it in animation tab in frames other than frame 0?? :cry:

Yes, I have checked other frames than 0. I also placed some keyframes, everything works fine...

i will try to understand messiah expresions in few days(if i can):D hihi

As DMack said, messiah's expressions are really powerful and easy to learn, and from looking at your scene I can see that you already get the hang of it - in fact, you are already making a pretty complex setup here, with all those expression driven holder bones ;) Some functions that you might find really useful for these kind of things, are "min", "max", "clamp", "abs", and such - great for constraining things in different ways :)

[CGTalk Moderation]

This thread has been automatically closed as it remained inactive for 12 months. If you wish to continue the discussion, please create a new thread in the appropriate forum.