View Full Version : .amc to .fbx conversion (cmu website)

08 August 2006, 08:57 PM
O.k. so this is a repost for those of you that are looking for this conversion method and for my students at Platt College.

There was a thread back sometime ago and one of the users here (Onikaze) actually came up with a video tutorial for this. So, with all due respect to Onikaze, I took the time to write it up awhile back just so I wouldn't forget the procedure. I know the video is still here somewhere, just do a search . If you want to use my documentation here it is :

Acclaim to MotionBuilder Conversion

Please note that this method is used solely for use in MotionBuilder. Obtaining this free data is courtesy of Carnegie Mellon University. Any type of commercial use must provide credits in this form:

The data used in this project was obtained from
The database was created with funding from NSF EIA-0196217.

Check the website for any further details.

Let’s get started!

Step1: Navigate to the appropriate website (

Step2: Figure out what category will best suit your needs. For this tutorial will be using Human Interactions.

Step3: Now navigate to a subcategory. In our case it would be two subjects.

You will now see a page that has a Trial # , Subject #, and Motion Description. You can navigate to the specific mocap either by clicking on a trial # or better yet the Subject #. A better understanding of this would be the subject representing the person/persons who perform the motioncapture and the trial as what action sequence or “take” as they call it in show business.

Step4: Clicking on Subject 18 takes us to the data files ready to be downloaded. There are five columns: tvd, c3d, amc, mpg, Animated. There is another column called feedback if you wish to leave feedback concerning the mocap. The only two that we are interested in would be Animated, to give us an idea of what the mocap will look like, and amc which is the mocap data to be downloaded.

Step5: Decide which mocap suits your needs. Next you will notice towards the top of the list an asf file in blue. Right click, “save target as”. Save to a subdirectory within the Templates folder in MotionBuilder. Do not rename file at this point. The asf file is the Subject mentioned earlier, sort of a source file for the mocap.

Step6: Now decide which Trial# will suit your needs and right click, “save target as” over the appropriate amc file. Save to a subdirectory within the Templates folder in MotionBuilder. For this tutorial we will use chicken dance (2 subjects - subject A).

Step7: In MotionBuilder import the asf file, in our case 18, and ignore the warning it gives you. Characterize the skeleton. MotionBuilder will give you another warning letting you know the joints are not named according to the FB/IK naming convention.

Step8: With your mouse in the viewport hit CTRL W to enter the node-based portion of MotionBuilder.

Step9: Drag and drop the joints from the skeleton to the appropriate FB/IK name in the character definition panel. I.E. root joint to Hips.

Step10: Once finished, characterize the skeleton once more. MotionBuilder will let you know whether you have any missing joints. Select the standard Bi-Ped option when prompted.

Step11: Save as CMUCharacterTemplate in the Characters subfolder in MotionBuilder. This will now be your template for your amc files.

Step12: With your CMUCharacterTemplate in the scene drag and drop an amc file, in our case the chicken dance, to any joint within the skeleton. Choose acclaim replace animation. An import window will ask you to choose an asf file, in our case it will be 18. Important Note: You MUST match up the correct files in order for the mocap to work, in our case 18.asf would have to match up with 18_15.amc (original file names).

Step13: Now plot your character, choose FK/IK for your control rig and save in your motions folder as an fbx. Note: If you try to play the mocap, it will be slow; the next steps will fix that!
Step14: Open up any character in the scene, drag and drop the mocap you just saved onto the story timeline. Play the motion clip and the character still moves slowly. Select the clip and change the Loop/Scale Clip button to scale.

Step15: In order for the motioncapture clip to play through normally (30FPS) we need to divide the total number of frames by four. Different motioncapture devices may calculate the FPS at a different rate for various purposes thus creating an unusually long motion clip.

Step16: Play back the motion clip and your character should now be doing the chicken dance! Save, plot, export as any other clip.

So if I forgot something or if you have any questions let me know...

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