Ahh thanks for the article. I think what he is getting at is the FK/IK switching that was discussed earlier.
I am not so much of an expert regarding that, but it seems to me that this is mostly an issue that comes up with movie animations, where you have much more and extreme animations. While with game aninations you have a small set which you can basically keyframe "to death" and thus the problem of misbehaving IK chains between the keyframes is almost non existant. But I might be totally wrong about that... I guess I will see once I start doing some animations.
The strechy behaviour of the first one? Yes you are right, but I think you can turn that off easily.
The rest of the controls of that setup seem quite nice though. Currently I am a bit unsure what to do next, maybe I will just go ahead and implement that spine, as it seems to be a decent setup (more standard than what the rig has right now, and the spline IK rig I have in mind is something that might tun out to be much better, or not work at all...).
Well, for now I am sick of dealing with that crappy Spline IK function... the concept is fine I guess, Blender's implementation just doesn't work properly for what I have in mind :(
it's supposed to be fixed in the svn now, so I will probably wait until the next Blender 2.5 beta arrives before continuing to implement a spine. So next I will try to give the rig some widgets ;)
I agree with that article, sometimes less choice is better, and those horrible ND (and preferrable also NC) licenses need to die! Lukily OGA does allow only a limited set of CC licenses.
The article forgot about the CC0 option, which is really useful to have in countries where you legally can't put your work in the "public domain".
Sorry to say that but you don't seem to know what you are talking about. Have a closer look at the vid you posted and you will see that the movement obviously follows the path of a bezier curve all the way from the hip to the shoulders.
In fact I have already a sort of working spine utilizing a spline IK that behaves very similar to the video. The problem is that there seems to be a bug in Blender 2.55 that makes it always deform the bones badly, regardless of whether or not you activate that checkbox or not:
Sadly there don't seem to be many people around who actually know this new feature in detail, and I just about tried everything now :( It's not the general feature though that is not working.
Of course you are right that a splineIK is a nice way to control many bones, but it is basically not IK at all. It is a "FK" method that makes a set of bones follow a curve. And with a curve like that you can very nicely control a human spine too. With more bones it of course animates smoother, but 3 or 4 are just fine to approximate a human spine.
Ehhm yes spline it is called, never the less I am quite sure that that is what is needed to duplicate the behaviour you linked in that video. It doesn't need that many bone though, you can map much less bones to the curve.
I will probably try doing a spine with that ;)
Oh and while playing with that I realized that I made a huge mistake by not putting the copy-rot rig into a seperate armature. Fixed in v72 (damn that was a lot of stupid extra work).
Edit... argg that buggy crap... in general the spline ik seems to do what I expected it to do (e.g. you would be very happy with the torso behaviour), but right now it really deforms the rest of the rig badly, and I have no idea why.
Arrgg... I think I figured out why there are no good tutorial on spine rigs for Blender, and why there are pretty much only FK spine setups in all rig you can download on the net. It seems like if you want to replicate the spines you can do in other animation packages (like the vid above) you need this brand new feature called "spine IK" and before it wasn't possible at all. The problem is that new feature seems wastly under-documented and also still pretty buggy :(
I had tried to use it already, but it didn't seem to work at all... that's why I didn't really had a second look at it. Turns out you need to set up a curve before. But even though that is probably easy... there are some problems that you have to seperate your rig in different armatures to avoid some bugs etc... really a mess to set up it seems.
Found two tutorials though... but both deal with non-human spine setups :(
I think it should be good enough for game cutscenes too... lets face it neither are game animations as high quality as movie animations in general, nor do open-source games have to reach that level. It's about speeding up the development to save man-hours for other more important things, while keeping the animation quality at a still very good (but maybe not perfect) level. A certain compromise has to be made.
Regarding the vid you posted (btw do you have more details on the setup of that?), I will go though the animations and try to replicate them with my rig:
1. movement of hip --- exactly the same if the pelvis bone is "grabbed"
2. movement of upper torso --- similar if head_target is grapped, but it does currently not extend as far downwards, there is some improvement possible there... but that is actually more IK rather than less.
3. rotation of hips --- similar to rotating the pelvis... doesn't move the upper body in my rig however. I am not sure if that is actually a good thing though. (It seems like the spine is a bezier curve in that mesh... possible to replicate in blender, maybe I will give it a try, not sure if that can be easily translated onto a bone only copy-rot rig)
4. rotation of upper torso --- sidewards up and down: possible (rotate spine.03), sidewards back and forth (move spine_target): possible, just back and forth: not really that possible with my rig... well sort of as that gets interpolated for most movements whem moving the head_target. Not really a very often used movement the latter... but you are right, there the rig in the vid is better in that regard.
5. Rotation of the middel torso --- possible by rotating spine.01, but again less movement resulting in the hips... maybe that's good or not.
Thanks for posting that vid! I might have a look at such a bezier spine and test it with my rig. It isn't currently a big difference however. Animations feel a bit smoother though, thus I guess you partially convinced me to try it out at least.
Hmm maybe I should rephrase my reasoning a bit... wasn't that clear I think.
For me a good rig is one that has only a few clickable controls that allow you to move a rig into more or less 99% of the positions you want it to be, while automatically dealing with all the tedious work of rotating individual bones. Of course it is nice to have the option of being able to tweak the exact locations also, but most of the time (if it is a good rig) you don't even have to bother with that. And having an easy one-click control outweights having individual precise control, if both don't work together (but of course an balance should be tried to achived).
In addition to that... this is ment to be a game rig, and in games you rarely have the close up shots you have in movies, thus I think for the sake of making the animation easier, we can sacrifice a bit of the precision if really needed.
Concerning the controller bones in movie rigs... well yes, but often that is tightly intervowen, with bones effecting one part of the mesh, while also acting as a target for another etc. And besides that, it is quite difficult to figure out how to replicate a behaviour if the rig is really complex, so these movie rigs are not exactly easy to learn from (I am looking at you man-candy >:( ).
Did you have a look at the UFO:AI music?
Ahh thanks for the article. I think what he is getting at is the FK/IK switching that was discussed earlier.
I am not so much of an expert regarding that, but it seems to me that this is mostly an issue that comes up with movie animations, where you have much more and extreme animations. While with game aninations you have a small set which you can basically keyframe "to death" and thus the problem of misbehaving IK chains between the keyframes is almost non existant. But I might be totally wrong about that... I guess I will see once I start doing some animations.
The strechy behaviour of the first one? Yes you are right, but I think you can turn that off easily.
The rest of the controls of that setup seem quite nice though. Currently I am a bit unsure what to do next, maybe I will just go ahead and implement that spine, as it seems to be a decent setup (more standard than what the rig has right now, and the spline IK rig I have in mind is something that might tun out to be much better, or not work at all...).
Well, for now I am sick of dealing with that crappy Spline IK function... the concept is fine I guess, Blender's implementation just doesn't work properly for what I have in mind :(
How about a spine rig like this:
http://vimeo.com/3807543
Or maybe like this:
http://www.vimeo.com/10685206
?
Edit: Ahh, it really was a Blender bug... http://blenderartists.org/forum/showthread.php?t=202910&p=1742175#post17...
it's supposed to be fixed in the svn now, so I will probably wait until the next Blender 2.5 beta arrives before continuing to implement a spine. So next I will try to give the rig some widgets ;)
I agree with that article, sometimes less choice is better, and those horrible ND (and preferrable also NC) licenses need to die! Lukily OGA does allow only a limited set of CC licenses.
The article forgot about the CC0 option, which is really useful to have in countries where you legally can't put your work in the "public domain".
Sorry to say that but you don't seem to know what you are talking about. Have a closer look at the vid you posted and you will see that the movement obviously follows the path of a bezier curve all the way from the hip to the shoulders.
In fact I have already a sort of working spine utilizing a spline IK that behaves very similar to the video. The problem is that there seems to be a bug in Blender 2.55 that makes it always deform the bones badly, regardless of whether or not you activate that checkbox or not:
http://blenderartists.org/forum/showthread.php?t=202910
Sadly there don't seem to be many people around who actually know this new feature in detail, and I just about tried everything now :( It's not the general feature though that is not working.
Of course you are right that a splineIK is a nice way to control many bones, but it is basically not IK at all. It is a "FK" method that makes a set of bones follow a curve. And with a curve like that you can very nicely control a human spine too. With more bones it of course animates smoother, but 3 or 4 are just fine to approximate a human spine.
Ehhm yes spline it is called, never the less I am quite sure that that is what is needed to duplicate the behaviour you linked in that video. It doesn't need that many bone though, you can map much less bones to the curve.
I will probably try doing a spine with that ;)
Oh and while playing with that I realized that I made a huge mistake by not putting the copy-rot rig into a seperate armature. Fixed in v72 (damn that was a lot of stupid extra work).
Edit... argg that buggy crap... in general the spline ik seems to do what I expected it to do (e.g. you would be very happy with the torso behaviour), but right now it really deforms the rest of the rig badly, and I have no idea why.
Arrgg... I think I figured out why there are no good tutorial on spine rigs for Blender, and why there are pretty much only FK spine setups in all rig you can download on the net. It seems like if you want to replicate the spines you can do in other animation packages (like the vid above) you need this brand new feature called "spine IK" and before it wasn't possible at all. The problem is that new feature seems wastly under-documented and also still pretty buggy :(
I had tried to use it already, but it didn't seem to work at all... that's why I didn't really had a second look at it. Turns out you need to set up a curve before. But even though that is probably easy... there are some problems that you have to seperate your rig in different armatures to avoid some bugs etc... really a mess to set up it seems.
Found two tutorials though... but both deal with non-human spine setups :(
http://users.xplornet.com/~gimble/blender/tutorials/spline_ik/spline_ik.htm
http://vimeo.com/12629274
I think it should be good enough for game cutscenes too... lets face it neither are game animations as high quality as movie animations in general, nor do open-source games have to reach that level. It's about speeding up the development to save man-hours for other more important things, while keeping the animation quality at a still very good (but maybe not perfect) level. A certain compromise has to be made.
Regarding the vid you posted (btw do you have more details on the setup of that?), I will go though the animations and try to replicate them with my rig:
1. movement of hip --- exactly the same if the pelvis bone is "grabbed"
2. movement of upper torso --- similar if head_target is grapped, but it does currently not extend as far downwards, there is some improvement possible there... but that is actually more IK rather than less.
3. rotation of hips --- similar to rotating the pelvis... doesn't move the upper body in my rig however. I am not sure if that is actually a good thing though. (It seems like the spine is a bezier curve in that mesh... possible to replicate in blender, maybe I will give it a try, not sure if that can be easily translated onto a bone only copy-rot rig)
4. rotation of upper torso --- sidewards up and down: possible (rotate spine.03), sidewards back and forth (move spine_target): possible, just back and forth: not really that possible with my rig... well sort of as that gets interpolated for most movements whem moving the head_target. Not really a very often used movement the latter... but you are right, there the rig in the vid is better in that regard.
5. Rotation of the middel torso --- possible by rotating spine.01, but again less movement resulting in the hips... maybe that's good or not.
Thanks for posting that vid! I might have a look at such a bezier spine and test it with my rig. It isn't currently a big difference however. Animations feel a bit smoother though, thus I guess you partially convinced me to try it out at least.
Hmm maybe I should rephrase my reasoning a bit... wasn't that clear I think.
For me a good rig is one that has only a few clickable controls that allow you to move a rig into more or less 99% of the positions you want it to be, while automatically dealing with all the tedious work of rotating individual bones. Of course it is nice to have the option of being able to tweak the exact locations also, but most of the time (if it is a good rig) you don't even have to bother with that. And having an easy one-click control outweights having individual precise control, if both don't work together (but of course an balance should be tried to achived).
In addition to that... this is ment to be a game rig, and in games you rarely have the close up shots you have in movies, thus I think for the sake of making the animation easier, we can sacrifice a bit of the precision if really needed.
Concerning the controller bones in movie rigs... well yes, but often that is tightly intervowen, with bones effecting one part of the mesh, while also acting as a target for another etc. And besides that, it is quite difficult to figure out how to replicate a behaviour if the rig is really complex, so these movie rigs are not exactly easy to learn from (I am looking at you man-candy >:( ).
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