Parent Constraint with maintain offset
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- rash
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hey everyone! could anybody answer to me? does have houdini parent with maintain offset, (I mean like in maya). Because I want to create FK hiearchy with three objects and stay position but affect with parent constrain. for example I did FK chain with nulls, and I have same position of bone chain with IK system, and I want to do parent constrain on the null hearchy but with stay FK hierarchy.
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- rash
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- goldfarb
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- rash
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- rash
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- goldfarb
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have a look at the attached file
I deleted the channel references to the CHOP on the par_FK nodes
I created a float parameter on the chain_goal1 called IKFK Blend
then I created a Blend Constraint:
select chain_bone1
click on Blend Constraint
change the settings to:
Simple
RX RY RZ -only
Keep Position: After
then select CTRL_FK_1
this will drop you into the constraint network -
I created a constraintblend
I wired the getworldspace and the then the offset nodes into the constraintblend
I added TWO blend parameters
put thin into the first: ch(“../../../chain_goal1/ikfk”)
and this into the second: 1-ch(“blend0”)
what this will do is blend between IK and FK based on the value of the IKFK Blend parameter on the chain_goal1
I repeated this for the other two bones.
hope that helps
I deleted the channel references to the CHOP on the par_FK nodes
I created a float parameter on the chain_goal1 called IKFK Blend
then I created a Blend Constraint:
select chain_bone1
click on Blend Constraint
change the settings to:
Simple
RX RY RZ -only
Keep Position: After
then select CTRL_FK_1
this will drop you into the constraint network -
I created a constraintblend
I wired the getworldspace and the then the offset nodes into the constraintblend
I added TWO blend parameters
put thin into the first: ch(“../../../chain_goal1/ikfk”)
and this into the second: 1-ch(“blend0”)
what this will do is blend between IK and FK based on the value of the IKFK Blend parameter on the chain_goal1
I repeated this for the other two bones.
hope that helps
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- rash
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arctor
I created a constraintblend
I wired the getworldspace and the then the offset nodes into the constraintblend
Hi arctor, I created constraint like you did, and the null have broken axis (attached img)… Why constraint do that in Houdini? And I found one more strange thinks, when I did constraint on the one object, so I can't do same constraint and get world or local pose from constraited object, it doesn't work… in attached file you can see “offset_up_Leg2” he took from “inf_FK_2” who already have constraint chop node. I want do several FK hierarchy and i don't want broke hierarchy but affect on nulls. Can I do this in Houdini?
Edited by rash - Dec. 20, 2017 08:47:14
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- goldfarb
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arctor
I can't really tell from your file what you are trying to do - and there seems to be a very strange scaling issue somewhere - when you tumble around and the transform handle gets bigger and smaller that is a sure sign something is wrong.
Michael
Yeah… I try to do something like IK and FK with 3 chains. The first chain its IK, second FK and last between blending (classic setup system). For me it important to do this of 3 chains. And I want to save chain FK hierarchy, and effected on the last chain. But chop constrait work very very strange, I did new scene, and created two nulls and created constraint, the null attached to anothe null, but axis stay on the place.
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- rash
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arctorI fixed scene, the problem was of “offset_up_Leg* ” nulls, I deleted hierarchy and it has worked. So if you look scene, you can see problem what I said before above. And on the control “chain__IK_Leg_goal1” I did some attribute for blending IKFK.
and there seems to be a very strange scaling issue
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- rash
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- goldfarb
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rashif you think there may be a bug please submit a bug report so we can reproduce it and get it fixed :
constraint network have bug. I found it! If you need I can show you
https://www.sidefx.com/bugs/submit/ [www.sidefx.com]
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