Inverse Kinematics Problem

  • Hello,

    I've got a bespoke character model in poser (pre-rigged) and when I turn on inverse kinematics on one of the legs and then grab the foot and move it on the Y axis the foot curls inward instead of staying straight. (Screenshot Supplied).
    alt text

    I'm very new to Poser (4 months) so I don't have the knowledge to figure out why it would be doing this? We have another bespoke model that moves fine, but for this one the feet are not playing ball.

    Does anyone have any ideas?

    Kind Regards,


  • At a guess, there's something wrong with the rigging of the right foot which causes it to do this. Have a look at the left foot in the joint editor, then compare against the same readings from the right foot. They should be the same, with the exception of x values being negative on the right and positive on the left.

    If it were me, I'd probably start by comparing the endpoints and origins on each foot.

    I have to ask though - isn't this an issue for the supplier of the figure to fix?

  • Hi Englishbob,

    Thank you for your reply and suggestion, I've fixed it :) I basically copied all the x, y, z joint data from the model without the problem and added it to the model with the problem and it has fixed the rotation when I lift the foot. Very happy to finally have this fixed!

  • Good to know - it does sound like it was a problem with the joint parameters. I forgot to mention that Poser's figure symmetry commands will allow you to copy joint parameters from one side of the body to the other, which should also have worked in this case. I'll mention it here on the off-chance that someone else comes looking for the answer to this.

  • While we're on the subject of IK, assuming shvrdavid or any other insider is listening, I'd like to suggest (for the 10th time) that SM adds an IK icon to the interface near the camera dots. Just arms and legs that can be clicked to turn on/off IK more quickly than messing about in menus. This is a function that I use with great regularity, and I'm sure that others would also find this an invaluable time saver.
    Also while I think about it, it would be great if there was a single button (or alt click) method for wiping all 9 camera pose buttons.

  • @matb The easier solution is to save your figure to your library in the zero pose with IK turned off.

    That's the first thing I do when I install a new figure.

    Then you never have to mess with IK again unless you NEED it on.

  • @Glitterati3D Thank you for your suggestion but I think perhaps I failed to explain myself properly. All the figures I use already have IK turned off by default, but when positioning them to interact with surfaces, objects or other figures, it's usually far easier to do so with IK turned ON and directly drag the hand or foot to the precise location rather than messing with multiple dials and judging which will correctly position the limb. However, I have found that saving scenes with IK on can cause problems so I often switch it on and off repeatedly as needed whilst setting up a scene. I was looking for a single click solution to do so, rather than having to go into the menu. I appreciate that the context menu is an advancement on the old figure menu solution, but when you are deep in your scene, every reasonable interface optimisation helps! :-)

  • @matb I'm not in front of my computer right now, but doesn't Poser already have an IK icon to break IK chains? Up by the edit tools?

  • @eclark1849 My bad. That's not what Chain Break is for.

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