Rigging CHOP Error - Blend

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I have been working on a character rig that requires the character to hold a weapon in either hand. We are able to get the Weapon attachment points on either hand. Now, I am setting up a constraint that allows the characters left or right hand to be constrained to the hand guard/barrel of the weapon. It works on one side of the character and not the other.

My process to lock the right hand to the hand guard/barrel of the weapon is: Select the R_hand_bone_auto null, select Blend, Simple, RX RY RZ, select Target Object which is a Null (L_Weapon_Attach) placed at the point of contact, Select Enter. I also do this for the R_arm_bone_goal_auto, instead I use the TX TY TZ values. Then I setup an additional IK Space Switch for the L_Weapon_Attach.



This works perfectly, and now I try the same process just reversed with the Left side. This time I get a CHOP error that I just can't figure out. I have tried starting with the Left side instead of the Right and still the same error.



I did try building the Constraint network manually and still the same errors. I have also tried to recreate the three nulls for the L_hand, and no errors have appeared. When I try to constrain the L_hand_bone to the L_hand_bone_ctrl the hand loses all function. Does anyone have an idea of what this error could mean? Thanks!
Edited by GlenD - 2019年8月28日 09:39:59

Attachments:
wpnFollow_gd.png (250.2 KB)
CHOP_error.png (62.1 KB)

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can you attach your file?
Michael Goldfarb | www.odforce.net
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goldfarb
can you attach your file?
Hi Michael,
I sent you a message with a link to the HDA. I can't post it on the forums at the moment. I have some limited info on versions in the Help Section of the HDA as well.
Glen
Edited by GlenD - 2019年8月28日 13:41:38
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I got the scene from Michael and had a quick look. There is an evaluation cycle when you add the second constraint. I think it comes from the constraint installed on L_arm_bone_2 which pulls from L_hand_bone_ctrl. The solution might be to add new OBJ nodes to prevent the cycle or to use a Fetch CHOP node instead of using a CHOP_Object node.
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Guillaume
I got the scene from Michael and had a quick look. There is an evaluation cycle when you add the second constraint. I think it comes from the constraint installed on L_arm_bone_2 which pulls from L_hand_bone_ctrl. The solution might be to add new OBJ nodes to prevent the cycle or to use a Fetch CHOP node instead of using a CHOP_Object node.
Thanks, I'll give it a try!
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@Guillaume The Fetch Chop worked well in the L_arm_bone_goal_auto and L_hand_bone_auto. I had to use a Transform VOP to reverse the translations that I needed.

In the end I actually went a different direction. I added another Object Offset to the Parent Blend lock the L_arm_bone_goal_auto to the R_Weapon_Attach null that is located where the hand holds the barrel of the weapon.

I used a Look At Constraint for the L_hand_bone_auto to Look At the R_Weapon_Attach. This gave us the rotations needed to keep the hand on the barrel. Then we just have to fine tune the hand animation instead of creating a brand new animation for the entire L Arm and Hand.

Thanks for the help!
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