LW2020 IK settings ?


New member
Hello all,

I've designed a character rig in an old version of LW, on times it was possible to edit some IK parameters (max/min radians, step size, iterations).

Opening it in LW2020 demo, and my rig goes nuts and shaky ... and no way to get hands on the window to edit those good ol' parameters.

Would there be a way for that ? Like new shortcut ? Or conf file edition ?

As those are experimental features, i understand Newtek didn't document those, but, well, without those i'm bound to stay in older LW ...

Thanks anyone by advance for help :)


LightWave Fan Boi
Which version of LW did you see those settings?

Was it in Motion options?

Was it a motion modifier under the IK and Modifier tab?

Was it a plug in?


Well-known member
Ctrl+Shift+F1 enables/disables experimental feature.
Unfortunately I know of no list of what they are.
I think in previous releases (2015, I think) one was bump maps as normal maps.

Wouldn't be that you use a tablet and have not set that option on. In 2018+ its messed up and has to be set to mouse or table depending on what you use to work correctly


New member
Shabazzy : nop it's totally core LW window that works in most old versions a 7 to 9 series for the least.

Chunderburger : yes i got them enabled in LW2020 but that usual Ik window seems to have no more shortcut (i'm on pc with keyboard) OR to not exist anymore ...


New member
PS : what i'm still unsure about is if :
1/ my old rig is broken but i managed to compensate wrong realization by that old IK window no more available
2/ my old rig is acceptable but LW2020 will never be able to make it work fine without those settings ...

Sure thing is i followed some tutorials to rig at realization time, so i have no reason to believe it's broken.
Also found some infos around the web that shaky rig was usual and solved with those hidden/expe features.

So still a mystery as a whole, hence i posted here hoping some people would have clue(s) for me (and community).


New member
Yes those you mention are regular features as to control each bone relation to the IK chain and possibly individual constraints in 3 rotation axis.

But what i meant and need is to access to some core settings that were classified experimental (min/max radian, step, iterations).
Seems they totally disappear and i therefore obtain shaky unpredictable IK chains in LW2020 that used to work perfectly in older versions ...

Makes the use of recent LW non-wishable for me, unfortunately :(
I could question my old IK designs, but as they use to work perfectly, what's wrong ?!

(PS : asked official support about it all, will post here if i get some enlightening reply)
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Well-known member
AFAIK, all those options are under the motion panel; You can set targets, poles, spline controller, rotation limits, constraints, add motion plugins, etc. Select your item, and press 'm'. This is what you should get:
Screenshot 2022-11-04 065116.jpg
Screenshot 2022-11-04 065309.jpg

If this won't do the job for you, I don't know what will.

Also, how old is the rig, and is it possible for you to post a stripped version so others can see what the problem might be?


New member
Here are the settings i change to make my IK chain work properly :

In my case : 2 max & 0.0001 min are perfect. I let step at 0.5 (and in next window, i set Iteration at 1000 instead of 500).

And here's my rig (masked the body to reveal bones) :

Head and legs are null-controlled. Arms are keyframes or scripted.

It works pretty fine in old LW from 7 to 9, e.g., as i can set upper values.
But in 2020 i tried to open it and it shakes all over, i'm unable to fix.
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Well-known member
You may be forced to rebuild the rig in 2020. Fortunately, this one is simple to do. I built a reasonable facsimile of it in 2020, and am noticing a couple of other issue unrelated to the jittering, but no jittering and noise.

I'll post the rig I cam up with here in a couple of hours, got errands to run.

The options you show don't appear to exist in 2020, though. Someone who knows lightwave better will have to speak up.

*edit*I did some research into the menu, it is/was an experimental feature. You used to be able to open it by Shift-control-F1 the pressing Control-Alt-F3. That doesn't appear to be working anymore. This is listed as a solution for jittery IK away from the origin in both a forum discussion from 2006, and in 1001 Tips and Tricks : Lightwave 3D 8.

I have attached the rig I came up with that appears to match yours closely - IK legs,, FK arms, head controlled by Null.
Screenshot 2022-11-07 100609.jpg

Move the character from the character root control, and not the master, I'll be glad to answer any questions.


  • simple rig.zip
    8.1 KB · Views: 27
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New member
Thanks that's a nice rig to reuse ! I'd just have to add fingers to equal mine 100%.
But for this current project, i'm already far ahead in LW 9+ renders so i think i'll finish it within already.

Still that's a great basis to move into 2020 later on, thank again for that.
Also, you seem to confirm what i feared : those exp features are gone in recent LW.


Well-known member
I couldn't get that one to pop up, no.

It sounds like completing your project in LW 9 is the best idea before moving on to another LW version.


New member
Yes. And once done, i'll precede any new projet by some dive into more recent LW, as i ignore most of newest features.
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