First off, I’m new to using XSI, so my apologies for dumb questions. 

OK, now, the objective:  I’m trying to learn how to export an animated character out of XSI 6.0 (or higher) as a Collada file for a game engine.

Here is what I’m currently doing, please tell me where I’m going wrong, and at the end, how to export out the animation correctly in Collada format for a game engine.

1) I Import a character model (envelope) from another modeler and reattach the materials.  From this I can now see my textured character in XSI.

2) I setup a Biped Guide Rig for my character (envelope).

3) I create the rig from the Guide (also making an SI3D skeleton Shadow Rig).

4) I create a Model in XSI (selecting the envelope and Biped Rig (not the Shadow Rig)

5) I set the envelope on the model (pick all the bones).

6) I weight the Envelope.

7) I tag the Biped Rig and the Mocap rig and import the BVH mocap with MOTOR.

At this point I have an animated textured model working in XSI.  It looks great.  But… now I need to export this out in Collada for a game engine.  How do I use the Shadow Rig, (or do I use Crosswalk… or both)?  What are the exact steps I would need to get this exported to Collada?

Right now my explorer tree has these main entries under the Scene Root:

Guide Rig
Biped Rig
Shadow Rig
Character (with Model inside)

Any help at this point would be greatly appreciated, or even a link to a step by step tutorial or other forum link that answers these questions.

Hi Becaris,

I’ve been doing the same thing and things are starting to come together (although there has been a lot to learn).

I haven’t used Shadow Rigs, but to your basic question… Just use crosswalk 3.1 and export out to the Collada XML file.

The XML file will have everything you need. To get animations, materials, and meshes working. I’ve been building an engine in XNA and it’s working.

Some things to watch out for:
1. XSI likes to put “Neutral Poses” in. Make sure your code handles this.
2. Make sure you’ve got the right keyed-parameters setup
- For example, effectors that have children need rotations & positions keyed
3. The collada file uses a “library” approach to storing data. You’ll find your importer does a fair amount of jumping around to load. Once you get the layout it makes sense.  Just start from the “<scene>” node.

Again, I’m not sure if you’re asking a tougher question, but I’ll help if I can.

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OK, I have managed to finish my animation, get rid of the XSI rig and I am left with my shadow rig.  Once that is done my Shadow Rig animates perfectly in XSI.  I can export it to Collada at this point.  However, if I try to import that Collada file back into XSI with Crosswalk it loads, but now the hands and feet of my biped do not work properly, becoming ‘detached’ from the arms and legs and stretching strangely.  What could be the problem?

OK, here is further information to show you what I am doing so you can see where I’m messing up the operation:

I have a rigged Biped (used the XSI stock guide/rig).  I have applied a BVH motion capture file to the rig, it animates decently. 

I have plotted the keyframes (I used the ‘Plot’ choice while in the Mocap to Rig menu) and made some adjustments and keyed those, now the animation looks better.

At this point I want to export the animation out to Collada for use in a game engine.  I middle button select the Shadow Rig and then do Select / Select Child nodes.  I go to the Animation menu and choose Plot, then Constrained Transforms (is this correct?).  It plots, then has a list of the constrains it wants do delete, which I accept.  The key frames now show in my Shadow Rig.  I delete the XSI rig, and the animation still plays correctly.

I then use Crosswalk to export the animation to Collada.  Everything seems to go well.

I import the Collada animation back into XSI with Crosswalk, but now the hands and feet of the biped no longer stay attached to the wrists and ankles… most of the rest of the model seems to animate correctly.  If I put the Collada exported animation into the game engine, it also has the same problems with the hands and feet.

What is the story?  Where did I go wrong?  HELP!

Hello,
I’m using collada for exporting assets to our game engine. This is how we do it:
We are exporting the shadow skeleton for its basic bone structure and correct hierarchy. Having a shadow skeleton + control rig allows us to use eg. the great quaternion spine in XSI. What we export to our game engine is the mesh + shadow skeleton. Thus, the enveloping must be also done to the shadow rig (not the control rig). I make a model from the shadow rig + mesh that I want to export, branch select it and enable “Export selection only” in the exporter. The XSI biped rig with shadow skeleton is somewhat tricky and might need some fixing. If you are switching the shadow bones from IK to FK they will rotate funky. This means you might have to re-constrain some of the shadow bones to the control rig. So make sure, and double check, everything (all ik/fk sliders etc) before you really start to animate, and remember to give the shadow skeleton a neutral pose. Also, for some unknown reason when you envelope something to the shadow rig, the envelope group doesn’t include the spine bones. So just add them manually to the shadow envelope group before enveloping and you’re good to go.

When I animate, I use the control rig. When i’m finished, I branch select the shadow skeletong, Selection->select child components. First “Plot all transformations” on the shadow skeleton, after that Store “Transformations - fcurves”. Now you have a clip that you can use. After this i save the original animation on the control rig also as a clip, Store->transformations fcurves. Also note that for some reason XSI creates “empty” keys on the shadow skeleton’s clips. To fix this, just click on the shadow skeletons mixer node’s clip that you just stored to open its properties, shift-select the top most keys that don’t seem to be connected to anything (if you have these) and remove them. For us, xsi chrashes on the Writing file-stage on collada export unless we delete these empty keyframes on the shadow clips.

Hello guys!
Sorry for the bump, but I really have the same problems even more. I need to export mesh with animation to our custom engine. We are using collada for that, so the problems I have:
First of all I used standard quadruped rig with SIskeleton, but it is behaving not like biped’s SIskeleton. I can plot on it the animation from the rig (bake keyframes onto bones), but the weigths are not baking. It’s the first problem, the second is shadow skeleton is animating in a strange manner, here is the video you can see.
the foot bones from the rig animated properly, but shadow skeleton’s foot bones are jumping… How can I fix that?
So as I correctly understood I need to fix that “jumping” problem and transfer weights from the original rig to the shadow. After that export the model with the mesh + shadow rig (with animation clip) only. Is it correct?
Thanks for any help, I’m trying to work it out for 3 days without any luck.

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