IK vs RK rigs

[Lungfish]

greetings, I'm curious as to whether anyone has any advice as to which rig to use when animating, I'm new to SFM and don't know which one I should use in the future.Here are my current info about the differences in rigs

IK:

-makes animations more realistic
-lags when clips are more than 10 secs
-requires you to detach rig to move other model parts
-allows hip movement
-elbows and knees are hard to manipulate the way I want them to move,
-you can use transform and rotation

RK:
-doesn't lag/require rig detachment
-pelvis is locked to whole model placement
-Allows movement of other rig parts without detachment
-can only use rotation

i made an animation with both rigs and I'm still not sure which is best
https://youtu.be/B_7eysObBjk

what are your guys opinions about it

[Zappy]

Inverse-kinematics can be better for placing a foot/hand on something (for example to keep a hand in the same place on a table while the character's upper body moves around), while forward-kinematics can be better for swinging motions (for example an uppercut or a big punch).

I suppose that a different, vary vague way to describe the differences would be that inverse-kinematics are about the "destination", while forward-kinematics are about the "journey", and sometimes one is more important than the other.


As one is better in some situations while the other is better in other situations, neither of them are strictly better or worse than the other; Depending on what you're trying to do, the best option may be to use a bit of both.

[episoder]

Originally posted by Zappy:

...use a bit of both.

https://steamcommunity.com/sharedfiles/filedetails/?id=661850284

[Marco Skoll]

Originally posted by Lungfish:

IK:
-requires you to detach rig to move other model parts

This is incorrect.

Rig scripts do often hide control categories, but they can be accessed by showing hidden controls in the Animation Set Editor's "gear" menu, and then (if you so choose) unhidden by the category's right click menu.

(However, generally, most controls are hidden because they're either now overridden by the IK rig and therefore would just be frustratingly unresponsive, or in some cases, because they would crash the program - two bones pointed at each other with aim constraints is sometimes useful for things like pistons, but will crash SFM if selected - so be careful what you poke).

It's inadvisable to keep adding and removing an IK rig if avoidable (it will cause the loss of keyframes, amongst some other possible issues).

Personally, I program all of my IK rigs in a similar way to episoder's, with nodes at the hip/shoulder that can be used to provide some FK capability.
(Although I have the parenting the other way around - my rigs default to normal IK parenting, and have to be locked to the FK nodes, rather than vice versa).