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View Full Version : Expressions ignore Motion Mixer clips -- why?



NigelH
11-27-2004, 09:57 AM
I have a character with a LOT of expressions driving various bones, morphs, etc. I want to use Motion Mixer to ease the pain of creating a long animation sequence (as it should, in theory), but when Motion Mixer clips are added to the timeline, morphs and expressions (that are looking for data in channels that are simply no longer there) just stop working. If I click the 'Edit Motion' button, the original motion is dropped back onto the timeline and everything works fine, but once the editing has stopped, and the clip goes back to Motiion Mixer, expressions stop working again.

Is there some way around this? I assume I must be missing something because it doesn't say in the docs "by the way, does not work with expressions". Seems like a pretty fatal drawback if this is the case. Anyone else had to deal with this?

Phil
11-27-2004, 10:41 AM
I have a character with a LOT of expressions driving various bones, morphs, etc. I want to use Motion Mixer to ease the pain of creating a long animation sequence (as it should, in theory), but when Motion Mixer clips are added to the timeline, morphs and expressions (that are looking for data in channels that are simply no longer there) just stop working. If I click the 'Edit Motion' button, the original motion is dropped back onto the timeline and everything works fine, but once the editing has stopped, and the clip goes back to Motiion Mixer, expressions stop working again.

Is there some way around this? I assume I must be missing something because it doesn't say in the docs "by the way, does not work with expressions". Seems like a pretty fatal drawback if this is the case. Anyone else had to deal with this?

From what I understand of MM, and the documentation is somewhat lacking, it deforms the geometry, rather than applies motion to the channels. It's more of a deformation plugin, not a motion plugin, in a manner similar to the way that you can bake animation into .mdd files. Expressions won't be evaluated in this case so you may need to bake the effects of expressions into the MM clips or (although I haven't tested this) into .mdd files. When MM scans the timeline, it should then import the animation.

Note that I have only used MM occasionally, partly due to the lack of any really useful documentation, so this is based on limited experience.

NigelH
11-27-2004, 11:52 AM
From what I understand of MM, and the documentation is somewhat lacking, it deforms the geometry, rather than applies motion to the channels. It's more of a deformation plugin, not a motion plugin, in a manner similar to the way that you can bake animation into .mdd files.

Then they should probably call it 'Deformation Mixer' instead. I have found that if the 'Motion Baker' plug-in is applied to specific channels, and expressions are pointed to those 'AfterIK' channels, then the expressions work regardless of Motion Mixer. Of course, LightWave has an annoying habit of confronting each solution with another problem. Now, when I try use the Expression Builder to replace the effected expressions, it turns out that the expression builder simply does not work (in LW[8] for MacOSX, anyway). The character was originally built in LW 7.5, but has since undergone several revisions in LW[8]. Suffice it to say, that I cannot go back to 7.5 at this point and expression building in LW[8] seems hosed, so I better not bother trying to edit the mechanics of the character at this point. As for baking in the effects of the expressions before saving the motion clips - well I haven't tried that before either, but it sounds time-consuming and right now, my sense of wonder at the thrill of discovery is at an all time low.

No, with deadline looming, it seems my only opotion at this point, is to keyframe the whole thing. Thanks a lot, NewTek, for another lost weekend spent with your 'time saving' animation tools.