Author Topic: Some bones from the skeleton are twisted  (Read 1269 times)

Offline Tangomajom

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Some bones from the skeleton are twisted
« on: November 01, 2016, 03:35:42 pm »
Hi Raft,

I would like to ask your help with a very tricky situation. I've created a model in Blender and I was able to load it to Android via the Ogre xml files and bones converter scripts. It works like charm.
Afterward I've tried to animate the bones individually from android to double check whether it has the same behaviour like in Blender. Most of the bones are moving as expected but looks like some of the bones are rotated and their relative axes are also mixed somehow.

For example if I'm rotating the clavickle bone around it's Y at Blender, the visual result on Android looks like when I rotated around it's X and vice versa. 

At first glance I thought the problem is with the different coordinate systems of Blender and JPCT, but if it's really the case, then why only just some of the bones are gone "mad"?

I think the problem is with the exported ogre xml. Unfortunately this forum denies any file which is bigger than 64kb, so I've uploaded it to my server slot: https://medev.hu/3d/MaleBody/MaleBody.rar .
Would be good if I can double check how the exported file look like, but I can't found any ogre xml importer or visualizer apps for Windows. 
I saw in your previous posts that you're using some kind of Ogre Visualizer app. Could you please give me the link for this app, and give me some info how to use it?

I would also appreciate if you can have a look at my attached files, maybe you can find something what I did not.


Thank you in advance,

Offline raft

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Re: Some bones from the skeleton are twisted
« Reply #1 on: November 01, 2016, 03:51:05 pm »
I was using this one as exporter for 3dsMax and also viewer. Especially the exporter was quite sucessfull.

http://www.ogre3d.org/tikiwiki/tiki-index.php?page=OgreMax+Scene+Exporter

The OgreMax site is not responding, not sure if a temporary problem or..

Offline AGP

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Re: Some bones from the skeleton are twisted
« Reply #2 on: November 01, 2016, 04:31:54 pm »
OgreMax is dead. I've been pointing it out for months. Hence, my project. Help me out?

Offline raft

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Re: Some bones from the skeleton are twisted
« Reply #3 on: November 01, 2016, 04:42:12 pm »
I dont really have time for that, besides I dont have a 3dsMax anymore

Offline AGP

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Re: Some bones from the skeleton are twisted
« Reply #4 on: November 01, 2016, 04:48:40 pm »
It's not about Max. The question was: once I have a transform matrix for each frame, how can I build my SkinClip out of it?

Offline AGP

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Re: Some bones from the skeleton are twisted
« Reply #5 on: November 01, 2016, 04:50:02 pm »
A matrix per joint per frame, obviously.

Offline Tangomajom

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Re: Some bones from the skeleton are twisted
« Reply #6 on: November 02, 2016, 07:22:45 am »
Thank you guys for the help. Unfortunately the page that raft linked is not responding. Do we have any alternative?
@AGP: I know that your topic is important for you, but please post your questions to your forum topic, just to not confuse us, or the others who will read this post in the future

So, to turn back to my topic:
I've tried to find some alternative for ogreMax, and I found an app called Meshy.(http://www.ogre3d.org/tikiwiki/Ogre+Meshy).

I think I found the problem, but the reason is still unknown for me. I don't know if the Meshy shows the bones different, or they really mixed up, but looks like the bones which are not exactly connected to it's parent are connected differently.
Please check the two attached picture from the original rig from Blender and the exported ogre format one.

I've double checked the skeleton xml and the bone hierarchy looks good. Do you have any idea why are the clavickle bones are connected to the head of the Spine bone instead of the tail?

Offline raft

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Re: Some bones from the skeleton are twisted
« Reply #7 on: November 02, 2016, 09:23:19 am »
not sure what exactly is happening there
Quote
but looks like the bones which are not exactly connected to it's parent are connected differently.
can you please explain this? are there bones which have no parent (except root bone)

attached is how skeleton looks in Bones. very much similar to Meshy but right clavicle is even looking more weird.

note: screenshot is from OgreSample can be found in samples dir, IMHO a handy tool to test your model / animation before going Android

Offline Tangomajom

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Re: Some bones from the skeleton are twisted
« Reply #8 on: November 02, 2016, 09:42:56 am »
Quote
can you please explain this? are there bones which have no parent (except root bone)
Of course, let me pick the clavicles as an example:
In blender I can see that the clavicles are the childs of Spine03, and I can see they connected to the tail of Spine03 (first picture from previous post).
However in Meshy the clavicle is connected to the head of Spine03. (second picture)

The skeleton xml is too big to attach it here. but here's the bone map and hierarchy:

Code: [Select]
<skeleton >
  <bones >
    <bone name="root" id="0" >
      <position y="0.000000" x="0.004884" z="-0.864401" />
      <rotation angle="3.125720" >
        <axis y="-0.001876" x="0.002568" z="0.999995" />
      </rotation>
    </bone>
    <bone name="pelvis" id="1" >
      <position y="0.017706" x="0.009123" z="0.837741" />
      <rotation angle="3.157657" >
        <axis y="0.577741" x="-0.002378" z="0.816217" />
      </rotation>
    </bone>
    <bone name="thigh_R" id="2" >
      <position y="0.081660" x="-0.115646" z="0.016301" />
      <rotation angle="3.056091" >
        <axis y="-0.162595" x="0.006344" z="0.986673" />
      </rotation>
    </bone>
    <bone name="calf_R" id="3" >
      <position y="0.432069" x="0.000000" z="0.000000" />
      <rotation angle="0.048844" >
        <axis y="0.818485" x="-0.506454" z="-0.271795" />
      </rotation>
    </bone>
    <bone name="foot_R" id="4" >
      <position y="0.390520" x="-0.000000" z="-0.000000" />
      <rotation angle="1.051425" >
        <axis y="0.035373" x="0.997835" z="0.055448" />
      </rotation>
    </bone>
    <bone name="toes_R" id="5" >
      <position y="0.169624" x="-0.000000" z="0.000000" />
      <rotation angle="3.128870" >
        <axis y="0.973478" x="0.029706" z="0.226845" />
      </rotation>
    </bone>
    <bone name="thigh_L" id="6" >
      <position y="0.081535" x="0.115647" z="0.016254" />
      <rotation angle="3.056110" >
        <axis y="0.162608" x="0.006301" z="-0.986671" />
      </rotation>
    </bone>
    <bone name="calf_L" id="7" >
      <position y="0.432112" x="0.000000" z="-0.000000" />
      <rotation angle="0.048815" >
        <axis y="-0.818230" x="-0.506691" z="0.271911" />
      </rotation>
    </bone>
    <bone name="foot_L" id="8" >
      <position y="0.390563" x="-0.000000" z="0.000000" />
      <rotation angle="1.051366" >
        <axis y="-0.035370" x="0.997835" z="-0.055445" />
      </rotation>
    </bone>
    <bone name="toes_L" id="9" >
      <position y="0.169629" x="0.000000" z="0.000000" />
      <rotation angle="0.464756" >
        <axis y="0.115608" x="0.981988" z="0.149451" />
      </rotation>
    </bone>
    <bone name="spine01" id="10" >
      <position y="0.177346" x="0.000000" z="-0.000000" />
      <rotation angle="0.427656" >
        <axis y="0.000075" x="1.000000" z="-0.000017" />
      </rotation>
    </bone>
    <bone name="spine02" id="11" >
      <position y="0.110510" x="-0.000000" z="0.000000" />
      <rotation angle="0.185709" >
        <axis y="0.000001" x="-1.000011" z="0.000000" />
      </rotation>
    </bone>
    <bone name="spine03" id="12" >
      <position y="0.116148" x="-0.000000" z="-0.000000" />
      <rotation angle="0.078377" >
        <axis y="-0.000002" x="0.999978" z="-0.000002" />
      </rotation>
    </bone>
    <bone name="clavicle_L" id="13" >
      <position y="0.170250" x="-0.000000" z="-0.000000" />
      <rotation angle="1.571824" >
        <axis y="0.002077" x="0.234202" z="-0.972186" />
      </rotation>
    </bone>
    <bone name="upperarm_L" id="14" >
      <position y="0.186862" x="-0.000000" z="0.000000" />
      <rotation angle="0.686020" >
        <axis y="-0.459979" x="-0.153060" z="-0.874639" />
      </rotation>
    </bone>
    <bone name="lowerarm_L" id="15" >
      <position y="0.263759" x="-0.000000" z="0.000000" />
      <rotation angle="0.144497" >
        <axis y="0.330465" x="-0.123323" z="0.935728" />
      </rotation>
    </bone>
    <bone name="hand_L" id="16" >
      <position y="0.282916" x="-0.000000" z="0.000000" />
      <rotation angle="1.743418" >
        <axis y="0.992426" x="0.118993" z="-0.030513" />
      </rotation>
    </bone>
    <bone name="thumb01_L" id="17" >
      <position y="0.016860" x="-0.016082" z="0.001996" />
      <rotation angle="2.183389" >
        <axis y="-0.834727" x="0.512873" z="0.200479" />
      </rotation>
    </bone>
    <bone name="thumb02_L" id="18" >
      <position y="0.042982" x="0.000000" z="-0.000000" />
      <rotation angle="0.130239" >
        <axis y="-0.406952" x="0.423240" z="0.809481" />
      </rotation>
    </bone>
    <bone name="thumb03_L" id="19" >
      <position y="0.037002" x="0.000000" z="0.000000" />
      <rotation angle="0.413834" >
        <axis y="0.034483" x="-0.996408" z="-0.077359" />
      </rotation>
    </bone>
    <bone name="index00_L" id="20" >
      <position y="0.037192" x="-0.000000" z="-0.000000" />
      <rotation angle="3.012851" >
        <axis y="-0.958519" x="0.261298" z="0.113864" />
      </rotation>
    </bone>
    <bone name="index01_L" id="21" >
      <position y="0.056785" x="-0.000000" z="-0.000000" />
      <rotation angle="0.829512" >
        <axis y="-0.533453" x="-0.548727" z="0.643682" />
      </rotation>
    </bone>
    <bone name="index02_L" id="22" >
      <position y="0.037158" x="0.000000" z="-0.000000" />
      <rotation angle="0.173344" >
        <axis y="0.076996" x="0.948542" z="0.307155" />
      </rotation>
    </bone>
    <bone name="index03_L" id="23" >
      <position y="0.024139" x="0.000000" z="-0.000000" />
      <rotation angle="0.189262" >
        <axis y="-0.174333" x="-0.980069" z="0.095293" />
      </rotation>
    </bone>
    <bone name="middle00_L" id="24" >
      <position y="0.037192" x="-0.000000" z="-0.000000" />
      <rotation angle="3.122542" >
        <axis y="0.991926" x="-0.098104" z="-0.080365" />
      </rotation>
    </bone>
    <bone name="middle01_L" id="25" >
      <position y="0.047485" x="-0.000000" z="0.000000" />
      <rotation angle="0.578610" >
        <axis y="-0.492799" x="-0.748925" z="0.443014" />
      </rotation>
    </bone>
    <bone name="middle02_L" id="26" >
      <position y="0.041070" x="0.000000" z="0.000000" />
      <rotation angle="0.167828" >
        <axis y="0.316871" x="0.934752" z="0.160737" />
      </rotation>
    </bone>
    <bone name="middle03_L" id="27" >
      <position y="0.029032" x="-0.000000" z="-0.000000" />
      <rotation angle="0.132120" >
        <axis y="-0.029757" x="-0.986498" z="-0.161075" />
      </rotation>
    </bone>
    <bone name="ring00_L" id="28" >
      <position y="0.037192" x="-0.000000" z="-0.000000" />
      <rotation angle="2.904945" >
        <axis y="0.991570" x="0.125271" z="-0.033103" />
      </rotation>
    </bone>
    <bone name="ring01_L" id="29" >
      <position y="0.042031" x="0.000000" z="0.000000" />
      <rotation angle="0.365672" >
        <axis y="0.138642" x="-0.908127" z="-0.395076" />
      </rotation>
    </bone>
    <bone name="ring02_L" id="30" >
      <position y="0.040239" x="-0.000000" z="0.000000" />
      <rotation angle="0.125652" >
        <axis y="-0.113431" x="0.944838" z="-0.307305" />
      </rotation>
    </bone>
    <bone name="ring03_L" id="31" >
      <position y="0.027510" x="0.000000" z="-0.000000" />
      <rotation angle="0.146784" >
        <axis y="-0.132122" x="-0.989528" z="0.058113" />
      </rotation>
    </bone>
    <bone name="pinky00_L" id="32" >
      <position y="0.037192" x="-0.000000" z="-0.000000" />
      <rotation angle="2.673930" >
        <axis y="0.932949" x="0.359854" z="0.010507" />
      </rotation>
    </bone>
    <bone name="pinky01_L" id="33" >
      <position y="0.045374" x="-0.000000" z="-0.000000" />
      <rotation angle="0.702573" >
        <axis y="0.492221" x="-0.356325" z="-0.794199" />
      </rotation>
    </bone>
    <bone name="pinky02_L" id="34" >
      <position y="0.032688" x="-0.000000" z="0.000000" />
      <rotation angle="0.118357" >
        <axis y="-0.002701" x="0.968474" z="-0.249115" />
      </rotation>
    </bone>
    <bone name="pinky03_L" id="35" >
      <position y="0.019855" x="-0.000000" z="-0.000000" />
      <rotation angle="0.198635" >
        <axis y="-0.052110" x="-0.977265" z="-0.205534" />
      </rotation>
    </bone>
    <bone name="clavicle_R" id="36" >
      <position y="0.199812" x="-0.033264" z="0.061997" />
      <rotation angle="1.772751" >
        <axis y="-0.075733" x="-0.032057" z="0.996613" />
      </rotation>
    </bone>
    <bone name="upperarm_R" id="37" >
      <position y="0.152543" x="-0.000000" z="-0.000000" />
      <rotation angle="0.428023" >
        <axis y="0.051732" x="0.423397" z="0.904466" />
      </rotation>
    </bone>
    <bone name="lowerarm_R" id="38" >
      <position y="0.263622" x="0.000000" z="0.000000" />
      <rotation angle="0.143737" >
        <axis y="-0.332338" x="-0.124178" z="-0.934948" />
      </rotation>
    </bone>
    <bone name="hand_R" id="39" >
      <position y="0.282921" x="0.000000" z="-0.000000" />
      <rotation angle="1.743419" >
        <axis y="-0.992481" x="0.118623" z="0.030159" />
      </rotation>
    </bone>
    <bone name="thumb01_R" id="40" >
      <position y="0.016851" x="0.016082" z="0.001999" />
      <rotation angle="2.183658" >
        <axis y="0.834654" x="0.513032" z="-0.200378" />
      </rotation>
    </bone>
    <bone name="thumb02_R" id="41" >
      <position y="0.042978" x="-0.000000" z="0.000000" />
      <rotation angle="0.130375" >
        <axis y="0.407649" x="0.423195" z="-0.809149" />
      </rotation>
    </bone>
    <bone name="thumb03_R" id="42" >
      <position y="0.036997" x="-0.000000" z="-0.000000" />
      <rotation angle="0.413836" >
        <axis y="-0.034358" x="-0.996407" z="0.077419" />
      </rotation>
    </bone>
    <bone name="index00_R" id="43" >
      <position y="0.037172" x="0.000000" z="-0.000000" />
      <rotation angle="3.013274" >
        <axis y="0.958492" x="0.261395" z="-0.113865" />
      </rotation>
    </bone>
    <bone name="index01_R" id="44" >
      <position y="0.056768" x="-0.000000" z="-0.000000" />
      <rotation angle="0.828851" >
        <axis y="0.531804" x="-0.549957" z="-0.643997" />
      </rotation>
    </bone>
    <bone name="index02_R" id="45" >
      <position y="0.037137" x="0.000000" z="-0.000000" />
      <rotation angle="0.196769" >
        <axis y="-0.475797" x="0.824788" z="-0.305554" />
      </rotation>
    </bone>
    <bone name="index03_R" id="46" >
      <position y="0.024126" x="-0.000000" z="0.000000" />
      <rotation angle="0.219170" >
        <axis y="0.524094" x="-0.850334" z="-0.047597" />
      </rotation>
    </bone>
    <bone name="middle00_R" id="47" >
      <position y="0.037172" x="0.000000" z="-0.000000" />
      <rotation angle="3.160929" >
        <axis y="0.991917" x="0.098146" z="-0.080419" />
      </rotation>
    </bone>
    <bone name="middle01_R" id="48" >
      <position y="0.047465" x="0.000000" z="0.000000" />
      <rotation angle="0.578959" >
        <axis y="0.492412" x="-0.749162" z="-0.443043" />
      </rotation>
    </bone>
    <bone name="middle02_R" id="49" >
      <position y="0.041048" x="-0.000000" z="-0.000000" />
      <rotation angle="0.173501" >
        <axis y="0.395327" x="0.913097" z="-0.099965" />
      </rotation>
    </bone>
    <bone name="middle03_R" id="50" >
      <position y="0.029016" x="-0.000000" z="0.000000" />
      <rotation angle="0.202310" >
        <axis y="-0.756365" x="-0.649586" z="0.077140" />
      </rotation>
    </bone>
    <bone name="ring00_R" id="51" >
      <position y="0.037172" x="0.000000" z="-0.000000" />
      <rotation angle="2.904867" >
        <axis y="-0.991560" x="0.125337" z="0.033143" />
      </rotation>
    </bone>
    <bone name="ring01_R" id="52" >
      <position y="0.042011" x="-0.000000" z="0.000000" />
      <rotation angle="0.362518" >
        <axis y="0.017680" x="-0.928076" z="0.371973" />
      </rotation>
    </bone>
    <bone name="ring02_R" id="53" >
      <position y="0.040217" x="0.000000" z="-0.000000" />
      <rotation angle="0.126428" >
        <axis y="-0.151300" x="0.926725" z="0.343959" />
      </rotation>
    </bone>
    <bone name="ring03_R" id="54" >
      <position y="0.027495" x="0.000000" z="0.000000" />
      <rotation angle="0.146042" >
        <axis y="0.073272" x="-0.994247" z="-0.078378" />
      </rotation>
    </bone>
    <bone name="pinky00_R" id="55" >
      <position y="0.037172" x="0.000000" z="-0.000000" />
      <rotation angle="2.673932" >
        <axis y="-0.932891" x="0.360005" z="-0.010530" />
      </rotation>
    </bone>
    <bone name="pinky01_R" id="56" >
      <position y="0.045358" x="-0.000000" z="-0.000000" />
      <rotation angle="0.663960" >
        <axis y="-0.393168" x="-0.412911" z="0.821538" />
      </rotation>
    </bone>
    <bone name="pinky02_R" id="57" >
      <position y="0.032670" x="-0.000000" z="-0.000000" />
      <rotation angle="0.131007" >
        <axis y="-0.426463" x="0.861088" z="0.276885" />
      </rotation>
    </bone>
    <bone name="pinky03_R" id="58" >
      <position y="0.019844" x="0.000000" z="-0.000000" />
      <rotation angle="0.206724" >
        <axis y="0.277492" x="-0.949614" z="0.145713" />
      </rotation>
    </bone>
    <bone name="neck" id="59" >
      <position y="0.229853" x="0.000000" z="0.075093" />
      <rotation angle="0.161672" >
        <axis y="-0.000018" x="1.000002" z="0.000534" />
      </rotation>
    </bone>
    <bone name="head" id="60" >
      <position y="0.119624" x="-0.000000" z="0.000000" />
      <rotation angle="0.071025" >
        <axis y="-0.000047" x="-1.000010" z="-0.002104" />
      </rotation>
    </bone>
  </bones>
  <bonehierarchy >
    <boneparent bone="pelvis" parent="root" />
    <boneparent bone="thigh_R" parent="pelvis" />
    <boneparent bone="calf_R" parent="thigh_R" />
    <boneparent bone="foot_R" parent="calf_R" />
    <boneparent bone="toes_R" parent="foot_R" />
    <boneparent bone="thigh_L" parent="pelvis" />
    <boneparent bone="calf_L" parent="thigh_L" />
    <boneparent bone="foot_L" parent="calf_L" />
    <boneparent bone="toes_L" parent="foot_L" />
    <boneparent bone="spine01" parent="pelvis" />
    <boneparent bone="spine02" parent="spine01" />
    <boneparent bone="spine03" parent="spine02" />
    <boneparent bone="clavicle_L" parent="spine03" />
    <boneparent bone="upperarm_L" parent="clavicle_L" />
    <boneparent bone="lowerarm_L" parent="upperarm_L" />
    <boneparent bone="hand_L" parent="lowerarm_L" />
    <boneparent bone="thumb01_L" parent="hand_L" />
    <boneparent bone="thumb02_L" parent="thumb01_L" />
    <boneparent bone="thumb03_L" parent="thumb02_L" />
    <boneparent bone="index00_L" parent="hand_L" />
    <boneparent bone="index01_L" parent="index00_L" />
    <boneparent bone="index02_L" parent="index01_L" />
    <boneparent bone="index03_L" parent="index02_L" />
    <boneparent bone="middle00_L" parent="hand_L" />
    <boneparent bone="middle01_L" parent="middle00_L" />
    <boneparent bone="middle02_L" parent="middle01_L" />
    <boneparent bone="middle03_L" parent="middle02_L" />
    <boneparent bone="ring00_L" parent="hand_L" />
    <boneparent bone="ring01_L" parent="ring00_L" />
    <boneparent bone="ring02_L" parent="ring01_L" />
    <boneparent bone="ring03_L" parent="ring02_L" />
    <boneparent bone="pinky00_L" parent="hand_L" />
    <boneparent bone="pinky01_L" parent="pinky00_L" />
    <boneparent bone="pinky02_L" parent="pinky01_L" />
    <boneparent bone="pinky03_L" parent="pinky02_L" />
    <boneparent bone="clavicle_R" parent="spine03" />
    <boneparent bone="upperarm_R" parent="clavicle_R" />
    <boneparent bone="lowerarm_R" parent="upperarm_R" />
    <boneparent bone="hand_R" parent="lowerarm_R" />
    <boneparent bone="thumb01_R" parent="hand_R" />
    <boneparent bone="thumb02_R" parent="thumb01_R" />
    <boneparent bone="thumb03_R" parent="thumb02_R" />
    <boneparent bone="index00_R" parent="hand_R" />
    <boneparent bone="index01_R" parent="index00_R" />
    <boneparent bone="index02_R" parent="index01_R" />
    <boneparent bone="index03_R" parent="index02_R" />
    <boneparent bone="middle00_R" parent="hand_R" />
    <boneparent bone="middle01_R" parent="middle00_R" />
    <boneparent bone="middle02_R" parent="middle01_R" />
    <boneparent bone="middle03_R" parent="middle02_R" />
    <boneparent bone="ring00_R" parent="hand_R" />
    <boneparent bone="ring01_R" parent="ring00_R" />
    <boneparent bone="ring02_R" parent="ring01_R" />
    <boneparent bone="ring03_R" parent="ring02_R" />
    <boneparent bone="pinky00_R" parent="hand_R" />
    <boneparent bone="pinky01_R" parent="pinky00_R" />
    <boneparent bone="pinky02_R" parent="pinky01_R" />
    <boneparent bone="pinky03_R" parent="pinky02_R" />
    <boneparent bone="neck" parent="spine03" />
    <boneparent bone="head" parent="neck" />
  </bonehierarchy>

I can find parent of clavicles. Is it possible that in the ogre skeleton I can't define more than on child for a bone? The Spine03 has three children (clavicle right and left and the neck)

Offline raft

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Re: Some bones from the skeleton are twisted
« Reply #9 on: November 02, 2016, 09:56:13 am »
I'm still unclear about this
Quote
bones which are not exactly connected to it's parent

Quote
Is it possible that in the ogre skeleton I can't define more than on child for a bone? The Spine03 has three children (clavicle right and left and the neck)
no, definitely not. otherwise you can only create a single string of bones, not a tree

there must be something different about clavicles that possibly Ogre exporter cannot process correctly. maybe some translation/rotation which is not baked into bind pose?

you checked the wiki page, right? (prepared by community, I never used Blender myself)
http://www.jpct.net/wiki/index.php?title=Exporting_from_Blender_to_Bones

Offline AGP

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Re: Some bones from the skeleton are twisted
« Reply #10 on: November 02, 2016, 07:15:33 pm »
To be fair, I did contribute with "OgreMax is dead." LOL

Offline Tangomajom

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Re: Some bones from the skeleton are twisted
« Reply #11 on: November 02, 2016, 10:05:33 pm »
Hi Raft,

Sorry for late answer. I've finally was able to launch your code samples. ( as I'm a beginner  I had to learn first how to launch nativa java codes).  Anyway, the skeleton what you received it's wrong. I've exported out from Blender again and now looks fine. At least a clavicles are on the right place, but somehow the X and Y axis of the clavicle bones are switched. (Only that ones).

Quote
bones which are not exactly connected to it's parent
Nevermind. As I compared and played a bit with the skeleton I have realized that your OgreSample code and Blender visualize the bones differently. E.g.: Blender shows the head an tail of the bones as well, but your code shows only head of the bone, and only those bones are visible which have children. That's why the head bone is not visible. But this is not a problem I think, just confused me a bit.

The main question is still the same. Why are the bones are rotated, and why not the complete skeleton? And of course how to solve it?
Is there a good ogre skeleton editor software in the wide internet?
« Last Edit: November 02, 2016, 10:07:26 pm by Tangomajom »

Offline raft

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Re: Some bones from the skeleton are twisted
« Reply #12 on: November 03, 2016, 09:59:08 am »
Quote
The main question is still the same. Why are the bones are rotated, and why not the complete skeleton? And of course how to solve it?
Is there a good ogre skeleton editor software in the wide internet?

dont know honestly. how do those bones behave in Meshy? in the example you had sent me there is only one animation moving the arm

Offline Tangomajom

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Re: Some bones from the skeleton are twisted
« Reply #13 on: November 05, 2016, 11:27:32 am »
Hi Raft,

After some hours/days of debugging I've found the root cause of the issue. If I'm exporting out the model with animation from Blender it is working fine, so the skeleton is OK.
The problem was on the android side. Some information from my project: I'm writing a fitness application and the porpouse of this part of the app is to show various fitness exercises with the same man.
Therefore I can't use the animation from the .bones file. I have to create them at runtime from an external JSON string.

I'm sharing my code with you, to not let the other developers suffer with it in the future. Maybe it's not the best at the point of performance, but at least it is working as expected. :)
Code: [Select]
    public static List<JointChannel> parseAnimation(AnimatedGroup animatedObject, JSONObject animation) {
        List<JointChannel> result = new ArrayList<>();

        SkeletonHelper helper = new SkeletonHelper(animatedObject);

        try {
            double animationTime = animation.getDouble("length");
            int totalFrames = animation.getInt("tot_frames");
            float frameTime = (float) (animationTime / totalFrames);

            JSONArray jsonBones = animation.getJSONArray("joints");

            for (int jt_i = 0; jt_i < jsonBones.length(); jt_i++) {
                JSONObject jsonBone = jsonBones.getJSONObject(jt_i);

                Joint animatedJoint = helper.getJoint(jsonBone.getString("name"));

                JSONArray jsonKeyframes = jsonBone.getJSONArray("keyframes");

                Quaternion[] rotations = new Quaternion[jsonKeyframes.length()];
                SimpleVector[] translations = new SimpleVector[jsonKeyframes.length()];
                SimpleVector[] scales = new SimpleVector[jsonKeyframes.length()];
                float[] times = new float[jsonKeyframes.length()];


                Matrix OriginalRotationMatrix;
                SimpleVector boneTranslation;

                // First joint has no LOCAL bind pose. In case of first bone we have to use the GLOBAL position.
                if (animatedJoint.getIndex() == 0) {
                    OriginalRotationMatrix = animatedObject.get(0).getSkeletonPose().getGlobal(animatedJoint.getIndex());
                    boneTranslation = animatedObject.get(0).getSkeletonPose().getGlobal(animatedJoint.getIndex()).getTranslation();
                } else {
                    OriginalRotationMatrix = animatedObject.get(0).getSkeletonPose().getLocal(animatedJoint.getIndex());
                    boneTranslation = animatedObject.get(0).getSkeletonPose().getLocal(animatedJoint.getIndex()).getTranslation();
                }

                SimpleVector newTranslation = new SimpleVector(boneTranslation.x, boneTranslation.y, boneTranslation.z);

                SimpleVector JointXAxis = new SimpleVector();
                SimpleVector JointYAxis = new SimpleVector();
                SimpleVector JointZAxis = new SimpleVector();

                OriginalRotationMatrix.getXAxis(JointXAxis);
                OriginalRotationMatrix.getYAxis(JointYAxis);
                OriginalRotationMatrix.getZAxis(JointZAxis);

                for (int k_i = 0; k_i < jsonKeyframes.length(); k_i++) {

                    JSONObject jsonKeyframe = jsonKeyframes.getJSONObject(k_i);
                    JSONObject jsonTranslationVector = findVector(jsonKeyframe, "loc");
                    JSONObject jsonRotationVector = findVector(jsonKeyframe, "rot");

                    // we have to create another Matrix from the original to be able apply all the rotations on the same bind pose
                    Matrix rotationMatrix = new Matrix(OriginalRotationMatrix);

                    if (jsonRotationVector != null) {
                        // I had to switch the angles do get the same direction as in Blender.
                        rotationMatrix.rotateAxis(JointXAxis, (float) (jsonRotationVector.getDouble("x")*-1f));
                        rotationMatrix.rotateAxis(JointYAxis, (float) (jsonRotationVector.getDouble("y")*-1f));
                        rotationMatrix.rotateAxis(JointZAxis, (float) (jsonRotationVector.getDouble("z")*-1f));
                    }

                    if (jsonTranslationVector != null) {
                        // The translation vector will be filled only at the root bone. The bones just rotating.
                        newTranslation.x += jsonTranslationVector.getDouble("x");
                        newTranslation.y += jsonTranslationVector.getDouble("y");
                        newTranslation.z += jsonTranslationVector.getDouble("z");
                    }


                    //Creating channel data
                    rotations[k_i] = new Quaternion(rotationMatrix);
                    translations[k_i] = newTranslation;
                    scales[k_i] = new SimpleVector(1, 1, 1);
                    times[k_i] = jsonKeyframe.getInt("frame") * frameTime;
                }

                JointChannel channel = new JointChannel(animatedJoint.getIndex(), times, translations, rotations, scales);
                result.add(channel);
            }

            return result;
        } catch (JSONException e) {
            e.printStackTrace();
            return null;
        }

    }

Here's a sample animation JSON, just as an input:
Code: [Select]
{"joints": [{"name": "root", "keyframes": [{"loc": {"x": 0.0, "y": 0.0, "z": 0.0}, "rot": {"x": 0.0, "y": 0.0, "z": 0.0}, "frame": 0}, {"loc": {"x": 0.0, "y": 0.0, "z": 0.0}, "rot": {"x": 0.0, "y": 0.0, "z": 0.0}, "frame": 50}]}, {"name": "thigh_L", "keyframes": [{"loc": null, "rot": {"x": 0.0, "y": 0.0, "z": 0.0}, "frame": 0}, {"loc": null, "rot": {"x": 1.6144294738769531, "y": 0.0, "z": -0.21467548608779907}, "frame": 50}]}, {"name": "calf_L", "keyframes": [{"loc": null, "rot": {"x": 0.0, "y": 0.0, "z": 0.0}, "frame": 0}, {"loc": null, "rot": {"x": -1.8954274654388428, "y": 0.0, "z": 0.0}, "frame": 50}]}, {"name": "foot_L", "keyframes": [{"loc": null, "rot": {"x": 0.0, "y": 0.0, "z": 0.0}, "frame": 0}, {"loc": null, "rot": {"x": -0.8970991969108582, "y": 0.0, "z": 0.0}, "frame": 50}]}, {"name": "clavicle_L", "keyframes": [{"loc": null, "rot": {"x": 0.0, "y": -0.9093164801597595, "z": 0.715584933757782}, "frame": 0}, {"loc": null, "rot": {"x": -0.14696186780929565, "y": -0.7961800694465637, "z": -0.12130868434906006}, "frame": 50}]}, {"name": "upperarm_L", "keyframes": [{"loc": null, "rot": {"x": 0.4538916051387787, "y": 0.19377639889717102, "z": 0.48314473032951355}, "frame": 0}, {"loc": null, "rot": {"x": -0.41943061351776123, "y": 0.04430050030350685, "z": -0.19194363057613373}, "frame": 50}]}, {"name": "lowerarm_L", "keyframes": [{"loc": null, "rot": {"x": 0.4298973083496094, "y": -0.35149678587913513, "z": 0.05556275695562363}, "frame": 0}, {"loc": null, "rot": {"x": 2.1684257984161377, "y": -0.703183650970459, "z": 0.19366076588630676}, "frame": 50}]}], "name": "MaleBodyV2Action", "length": 2.0, "tot_frames": 50}

And a small snippet for the usage of the parser method below:
Code: [Select]
  MaleBody = loadMaleBody(R.raw.malebody_v2);
  MaleBody.setAutoApplyAnimation(true);
  SkinClip ExerciseClip = new SkinClip(MaleBody.get(0).getSkeleton(), ParseUtils.parseAnimation(MaleBody, new JSONObject("json string from input below")));
  SkinClipSequence clipSeq = new SkinClipSequence(ExerciseClip);
  MaleBody.setSkinClipSequence(clipSeq);

I hope will help for you guys in the future. Thank you Raft for the support and help. The procedural animation sample was really helpful at this time.
This is an awesome library, and I wasn't able to achieve my goals without this.


Regards,
Tangomajom

Offline raft

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Re: Some bones from the skeleton are twisted
« Reply #14 on: November 07, 2016, 09:23:57 am »
I'm glad you resolved it.

Quote
If I'm exporting out the model with animation from Blender it is working fine, so the skeleton is OK. The problem was on the android side.
But I'm not sure what you meant here ;)