The project I choose is a game where robots could fight. I have done all the job at importing models in my XNA game, but I am having difficulty playing a FBX animation. I could use skinned model example from microsoft website,but the problem is, my FBX file does not contain joints (skeleton). Arms, legs and head are controlled in the way of rotating at pivot centre (you can see how it looks in the bottom pictures).

PICTURES: http://postimage.org/image/7gnns9sz7/
http://postimage.org/image/t4cm2ptdf/

My question is:"How can I change skinned model example, so that would play FBX animation without my model containing skeleton?" or "Is this even possible?"

My problem is not rotating objects, but playing animation. Maybe I don't understand or maybe I didn't explained the problem correctly.

Let's say that we have a box and that we would like to extrude every 6 faces. But we would like to extrude them from 0 seconds to 10 seconds (slowly extruding). This would be our *fbx animation.

And my question is: "How can I play that animation, if the animation doesn't contain skeleton?"

PS: Extruding box is just an example.

I am not the best person to explain this but 'm gonna try.

If for example you have animation that lasts 10 seconds you could set 10 animation keys/sequences as one for each second, then for each key you have each vertex at certain position and/or orientation. Then you move your animation track "cursor" over time and interpolate position/orientation of each vertex to make animation going.

                     cursor
             0--------|------1---------------2---------------3---------------4---------------5---------------6---------------....10
vertex1 xy(30,10)      xy(40,10)     xy(50,20) ....
vertex2 xy(10,10)      xy(20,10)     xy(30,20) ....
vertex3 xy(10,10)      xy(10,10)     xy(10,10) ....
...

// for each vertex
cursor.time += deltaTime * animSpeed;
cursor.time = fmod(cursor.time, 10s);
float lerpTime = (cursor.time - key[keyInx].time) / (key[keyInx +1].time - key[keyInx].time); // 0 - 1
CurrentVertexPos = lerp( key[keyInx].xy, key[keyInx+1].xy, lerpTime );

Ok. I think I understand what you mean. But how could I change skinning model example from Microsoft for working the same way but with the difference that my model would not contain skeleton?

PS: I am new to XNA so please don't be angry if I missed the point.

Thank you all for answering so quickly.

So just to make sure, if I understand last reply. I cannot really play animation from *fbx without skeleton. But I can rotate parts of the 3D model, so it will look like playing animation (something like that is used in example you gave it). But if I do rotating (or scaling or moving) in code, wouldn't than be animating (in code) the "walk" pretty hard.

I mean you would have to rotate multiple parts, for having natural "walking" cycle. Walk cycle would be much easier to create in autodesk maya than writting code.

Example what I mean with walk cycle: