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Adjusting foots to ground
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rstralberg Offline
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Post: #1
Adjusting foots to ground
Hi there.

Any suggestion on how to approach this.
Some simple method of keeping an animated character foots to ground.
As you see here it looks a bit weird as it is now.
The character is rigged with a standard Mixamo-rig

   
04-20-2016 02:22 PM
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Zervox Offline
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Post: #2
RE: Adjusting foots to ground
Technically there is no real 'simple' method of doing this, but this is an example where inverse kinematic is used.
04-20-2016 02:43 PM
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rstralberg Offline
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Post: #3
RE: Adjusting foots to ground
Yes. I guess IK is the only way. Have to study that a bit then.
Thanks smile
04-20-2016 02:45 PM
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Zervox Offline
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Post: #4
RE: Adjusting foots to ground
There are other ways, but I'd say it's well worth it to spend time on IK solving with animation blending.

I guess this would work as a good starting point(as a working example that is).
Example
screenshot on first page.

georgatos7 posted some compiled demo's(very impressive spider) which means he probably can give some pointers for this if he has the time. smile
The Room
(This post was last modified: 04-20-2016 03:28 PM by Zervox.)
04-20-2016 03:14 PM
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rstralberg Offline
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Post: #5
RE: Adjusting foots to ground
(04-20-2016 03:14 PM)Zervox Wrote:  There are other ways, but I'd say it's well worth it to spend time on IK solving with animation blending.

I guess this would work as a good starting point(as a working example that is).
Example
screenshot on first page.

georgatos7 posted some compiled demo's(very impressive spider) which means he probably can give some pointers for this if he has the time. smile
The Room

Great. Thanks! Good to have a starting point.
04-21-2016 01:31 PM
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Esenthel Offline
Administrator

Post: #6
RE: Adjusting foots to ground
In the above screenshot, you need to:
-move the entire mesh down (simple)
-rotate the right leg so that it's positioned higher (hard)

To rotate the leg, you need to adjust upper and lower bones of the leg.

How to rotate a single bone please look at tutorial:
10 - Animation/04 - Manual Editing

it transforms the 'bone.orn', but faster way would be to operate on 'bone.rot'
04-22-2016 12:44 AM
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RedcrowProd Offline
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Post: #7
RE: Adjusting foots to ground
bringing the entire mesh down wouldnt be annoying to deal with the capsule of the char ? you dont want his feet to just be not in the capsule, nor hills stopping it ? as you dont want the capsule to enter either the ground ?
04-22-2016 03:50 AM
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rstralberg Offline
Member

Post: #8
RE: Adjusting foots to ground
Thanks for the suggestions. I guess the best way to approach this would be some simple IK as Zervox suggested.

This is what I have in mind.
1. One simple IK-chain (foot - knee - upperleg) for each leg + code for that
2. Once per frame
2a. After animation is done check where foot is.
2b. Move foot up or down so it touched the ground using the IK-code
2c. Update animation.
04-22-2016 10:43 AM
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Pixel Perfect Offline
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Post: #9
RE: Adjusting foots to ground
I wish you luck with this. Having previous experience of seeing a friend spend roughly 6 months perfecting a foot placement system back in my Leadwerks days I know how complicated it gets. Getting a system that reacts to most situations well, is tricky but doable, getting one to work in all situations and looking natural in terms of the animation, virtually impossible. You see issues with this even in the best AAA titles.

But a simple system that results in much better and more believable placement is desirable and worth putting time into. As Zervox mentioned, georgatos7's spider example was very impressive and shows what can be done.

To be honest, a simple foot placement system would be a really worthwhile addition to the engine so everyone could benefit from it, as most people would prefer to be spending their time programming game play rather than a desirable game engine mechanism.

Look forward to seeing what you come up with Roland.
04-23-2016 09:09 AM
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RedcrowProd Offline
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Post: #10
RE: Adjusting foots to ground
^ agree with pixel, this kind of thing would be really nice to see built in into the engine, like weather system, controller animation stopping on not movement possible. it just gives more time prog other things than core system.
(This post was last modified: 04-23-2016 09:35 PM by RedcrowProd.)
04-23-2016 09:34 PM
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