look at eye in a stretchy face

Become a member of the CGSociety

Connect, Share, and Learn with our Large Growing CG Art Community. It's Free!

Thread Tools Display Modes
  03 March 2012
look at eye in a stretchy face

How do I keep the eye 's lookat rotation and at the same time stretch with the head's stretchy bone?
there is a double transformation(position-rotation-scale) happens to the eye from the ffd spacewarp that is skined to the head stretchy bone to stretch with it and the look at target that is linked to the ctrl of the head

3ds max

Last edited by mhdmhd : 03 March 2012 at 10:39 PM.
  03 March 2012
Hi Mahmoud,

It would help if you had a scene file. It might be just simple mistake easily fixed. However, if I understood correctly what your case is here is a solution:

FFD spacewarp seems like good choice, but remember, it does not transform node/object, it moves verts.

1. Have mesh, make bones + skin to mesh (head, in this case)
2. Create eye containing FFD WSD object
3. Skin FFD WSD object to same bones as head
4. Move eye into FFD volume, link to FFD spacewarp. Now you are mostly done with eye *mesh*
5. Create box or similar *geometry*, call it "root_attach"
6. Now bind this to FFD. This is important. Since pivot is not moving....
7. Create point, call it "root_point"
8. Attach constrain "root_point" to "root_attach" front facing polygon
9. Create point, call it "lookat"
10. Make "root_point" lookat constrained to "lookat"
11. Finally, orient constrain eye mesh to "root_point"

This way, your "root_attach" + "root_point" simulate moving pivot inside FFD volume, otherwise it will stick to default location. There is no need to link eye ball. It will move inside FFD volume.

Hope this helps, let me know if it works for you!
Scripting and Rigging Reel 2012 - Open for full-time position or freelance work

Last edited by Transmuter : 03 March 2012 at 05:31 PM.
  07 July 2012

Transmuter, you're a genius. I really struggled with this and your method works perfectly. Thanks
  11 November 2012
Almost perfect!

Hey guys, I was testing this eye setup but I got a problem.. When I rotate the head (it's a 4 bone chain made with CAT) the eyes goes a bit too far up.. It's doesn't keep looking at the correct point! The pivot of the eye mesh is following the rotation correctly, but when the FFD deforms the eyes, the mesh follows the pivot rotation and end up with an "offseted look at constraint".

I'll put some images to show you my problem

The blue circle is the "lookat", the green point with axis is the "root_point" and the "root_attach" is the box is inside the eye mesh.

I'm having a bad time trying to fix this.. any idea?

  11 November 2012
If you are using a stretchy head bone, you can do it by having two skin modifiers: one for skinning the eye's rotation via lookat bone, and another on top of it for skinning to the squash/stretch bone. That way you first turn the eye, then stretch it.

[edit] Forgot to mention: link the eye mesh to what the lookats are linked to (usually the head bone), else you will be getting double transforms for the two skin modifiers.

Last edited by Zhalktis : 11 November 2012 at 08:18 AM.
  11 November 2012
This doesn't make much sense for me.. I should create a bone with look at constraint for the eyes, and skin the eye mesh to this bone, then make another skin for the whole mesh + eye? I'm using the Trasmuter setup, with FFD, box, attachment constraint etc..

I think I got it working properly now! Your [edit] part made me think a bit and I linked the eye, FFD and box mesh to the central head bone (the same that the look at target is linked) and uncheck the "Inherit scale" on the Link Info panel. Seems pretty good now!

  11 November 2012
Thread automatically closed

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.
CGTalk Policy/Legalities
Note that as CGTalk Members, you agree to the terms and conditions of using this website.
Thread Closed share thread

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

vB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Society of Digital Artists

Powered by vBulletin
Copyright 2000 - 2006,
Jelsoft Enterprises Ltd.
Minimize Ads
Forum Jump

All times are GMT. The time now is 04:14 PM.

Powered by vBulletin
Copyright ©2000 - 2018, Jelsoft Enterprises Ltd.