I am working on translating an old RTS game engine I wrote from DirectX9 to XNA. My old models didn't have animation & are an old format, so I'm trying with an FBX file. I temporarily "borrowed" a model from League of Legends just to test if my rendering is working correctly.

I imported the mesh/bones/skin/animation into Maya 2012 using an "unnamed" 3rd-party import tool. (obviously I'll have to get legit models later, but I just want to test if my programming is correct). Everything looks correct in maya and it renders the animations flawlessly.

I exported everything into a single FBX file (with only a single animation). I then tried to load this model using the example at the following site: http://create.msdn.com/en-US/education/catalog/sample/skinned_model

With my exported FBX, the animation looks correct for most of the frames, however at random times it screws up for a split second. Basically, the body/arms/head will look right, but the leg/foot will shoot out to a random point in space for a second & then go back to the normal position. The original FBX from the sample looks correct in my program.

It seems odd that my model was imported into maya wrong, since it displays fine in Maya. So, I'm thinking either I'm exporting it wrong, or the sample code is bad & the model from the sample caters to the samples bad code.

I'm new to 3D programming & maya, so chances are I'm doing something wrong in the export. I'm using mostly the defaults, but I've tried all 3 interpolation modes (quaternion, euler, resample).

  • \$\begingroup\$ Sorry that this won't be much help, but I have also encountered problems importing skinned models from 3dsmax into XNA via FBX, with much the same symptoms as you describe only more pronounced; ultimately I was unable to get it to work (which wasn't a concern to me but only because I was creating my own animation editor!). Can you import the FBX back into Maya or another application that supports FBX (Max?) and have it display correctly? I would be interested to know if you manage to solve it. \$\endgroup\$ – sebf Jul 28 '11 at 10:29
  • \$\begingroup\$ Good idea. I opened the FBX in Maya & it renders fine, but if I open the file in 3ds Max, it has the same problem as my game engine. So, it must be something wrong with the file, & not with my code. I'll keep troubleshooting & find out if I was exporting with Maya wrong, or if the League of Legends importer is broken. \$\endgroup\$ – Devin Garner Jul 29 '11 at 9:59
  • \$\begingroup\$ I found that Maya uses 24fps by default & 3dsMax uses 30. When I made them both use the same fps, the problem went away inside both apps, but stayed in my XNA game. However, googling showed that a lot of people have this issue with FBX. I exported to .x using PandaSoft directX exporter & the animation rendered perfectly in my XNA game! \$\endgroup\$ – Devin Garner Jul 29 '11 at 11:48
  • \$\begingroup\$ Thanks for the update. Glad you got it sorted. The distortion due to frame rates is interesting, I wonder what else is hard-coded in the XNA CP importer? There must be quite a bit since FBX requires an entire SDK to interact with it. \$\endgroup\$ – sebf Aug 1 '11 at 18:16

I suggest you use kw X-Port for 3DS Max, as it's specifically made for use with XNA.


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