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Sebasvideo
08-25-2013, 10:16 AM
I've been trying to export a scene from Modo to Lightwave so I can use the "Send to AE" LW feature and I found some problems that I would like to learn more about to see what's wrong.

This is a simple scene with a spaceship and a camera traveling more or less around it, but not in a 360 motion. It has 8 keyframes with custom bezier curves.

- From Modo I can export to a number of formats, FBX 2006.11, 2010 and 2013, Collada 1.4.1, Alembic and some others.

- When I open the Collada file in Layout, the camera only rotates, but it doesn't move.

- FBX 2006.11 gives me the eight keyframes, but the curves are converted to flat, so when the camera gets to each keyframe, it stops for a moment and then keeps going. This makes it useless, unless I change the curves again, but it wouldn't be exactly as they were in Modo.

- FBX 2010 inserts one keyframe per frame, so the camera motion is mostly the same, but I see that there's one frame that goes crazy for no reason, with two surrounding frames also out of whack. For example, at frame 562, Z rotation (B in LW, which I have no idea what it means- the blue one), is -15.51. in the previous frames, to 25.69 at frame 564, and 563 starts the change at -18.31

- Either FBX version brings wrong settings. Frame rate is set to 23.976 in Modo, but it always comes at 30.00 fps, which messes up keyframing, so I have to set it manually. Frame size comes at 320x200, when it's 1280x536 in the Modo project. Also in the project, the scene length is 1100 frames, but it always comes in at 60 frames, so I have to set it in Render Globals as well as the range in the timeline. All these settings have to be changed when importing the FBX, because if you do a Send to AE like that, it will mess up your AE comp. It will change the frame rate and the dimensions.

- I can't export FBX 2013 from Modo, it gives me an error.

- Apparently there's no support in LW for Alembic, since I typed a search for it in the 11.6 manual and it didn't find the word.

So what's the reason for all this miscommunication between Modo and LW? Is Modo not writing to FBX correctly, or is LW not reading correctly? Is there anything I can do so the settings translate correctly?

Thanks

RebelHill
08-25-2013, 10:34 AM
FBX doesnt really transfer curve type data (it does hold it, u can sling beziers back n forth between maya and MB for instance, but hardly ever does some other package either write it in, or read it out)... so you really need baked key curves. The second option with the baked curves is obv attempting to do that, but modo's probs just making errors doing it via its fbx export (most likely its not euler filtering right, hence the jumpy frame). Bake the curves first in modo, then do the fbx export and you ought be fine. As regards the framerate... keys arent recorded in terms of frames, they're recorded in terms of TIME, which is framerate independent. LW is just opening the fbx in whatever framerate was already set in LW, just set it back as desired and everything should be fine from that perspective.

Sebasvideo
08-25-2013, 10:48 AM
As regards the framerate... keys arent recorded in terms of frames, they're recorded in terms of TIME, which is framerate independent. LW is just opening the fbx in whatever framerate was already set in LW, just set it back as desired and everything should be fine from that perspective.

I don't get it. Time is not independent from frame rate. 1100 frames at 23.976 is a different time length than 1100 frames at 30 fps. And that's what annoys me about this conversion, because even if it doesn't transfer the settings correctly, at least it could leave the ones LW already has, but no. I have Layout to 23.976, 1100 frames and 1280x536 by default, so when I open Layout, that's what I get. When I load the FBX, I have 30 fps, 60 frames length and 320x200.

RebelHill
08-25-2013, 10:51 AM
Time is independent from (or an aside to, whatever word you prefer) framerate...

If Im working at 24fps, and I set a key at frame 24... the key REALLY exists at 1 second. If I now go and alter my framerate to 30 fps... the key is STILL at 1 second (now frame 30). Changing the fps of your scene will not alter the TIMING of the animation.

Sebasvideo
08-25-2013, 11:50 AM
Time is independent from (or an aside to, whatever word you prefer) framerate...

If Im working at 24fps, and I set a key at frame 24... the key REALLY exists at 1 second. If I now go and alter my framerate to 30 fps... the key is STILL at 1 second (now frame 30). Changing the fps of your scene will not alter the TIMING of the animation.

It does change it. The only place where fps doesn't change the timing of the animation is real life. But anything that is either film or digital does. In this particular case, the imported FBX from a scene that was 23.976 and is opened as 30.00 fps in LW changes the timing, and therefore the position of the keyframes. It's simple enough; in Modo the length of the scene is 1100 frames, which is 45.879 seconds at 23.976 fps. When imported into Layout, which turns it into a 30 fps animation, the 1100th frame is at 36.667 seconds. So all three are part of the equation. Obviously when changing the frame rate in Layout to 23.976, frame 1100 is at 45.879 seconds. So one second at 23.976 fps is not the same as one second at 30 fps.

RebelHill
08-25-2013, 12:15 PM
This ISNT video though... The time does remain the same, I promise you. Ive worked with fbxing stuff around all over the place and shifted frame rates on animation for years... trust me.

If you have something at one fps, with a frame 1100... and you change the fps then ofc the "1100 position" on that timeline will represent a different point in time... BUT the actual frame which was at 1100 will no longer be at the same frame.

Just try it... Set LW to 24fps... create a key for the camera at frame 24 (1 second). Now change the scene fps to 30... where's that frame?

Sebasvideo
08-25-2013, 12:31 PM
This ISNT video though... The time does remain the same, I promise you. Ive worked with fbxing stuff around all over the place and shifted frame rates on animation for years... trust me.

If you have something at one fps, with a frame 1100... and you change the fps then ofc the "1100 position" on that timeline will represent a different point in time... BUT the actual frame which was at 1100 will no longer be at the same frame.

Just try it... Set LW to 24fps... create a key for the camera at frame 24 (1 second). Now change the scene fps to 30... where's that frame?

This IS video. It has a timeline, and the rendered sequence has the purpose of being video, film, whatever you call it. Now, if in Lightwave you create a key at one second with fps at 24, then change the fps to 30 and it stays at 1 second, that's good, it means Lightwave moves the keyframe automatically so that it stays at the same time. But it is clearly not the case here, where a keyframe that is set in Modo at frame 950 is at time 39.623, but when that FBX is imported into Lightwave, frame 950 is now at time 31.667. So no, at least in this case, keyframes are dependent on fps.

RebelHill
08-25-2013, 12:36 PM
But its NOT video... not yet... not until you render it. Its keys in a 3d animation timeline, and that IS based on time, not fps (unless modos unlike all other apps in that regard). So, assuming modo's not that stupid... then either modo isnt outputting the fractional fps properly to fbx, or LW isnt reading it in right (when I bring stuff in from MB LW picks up the fps just fine, so maybe modo, or maybe just a clash of the 2). So then, the fix is to change your framerate in modo first (which should keep the same timing, by keeping the keys in seconds rather than frame numbers), then export it to fbx, then once in LW, change back to the desired framerate.

clintonman
08-25-2013, 01:03 PM
...LW is just opening the fbx in whatever framerate was already set in LW, just set it back as desired and everything should be fine from that perspective.
I save a fbx from LW at 24 fps and if I clear the scene and set to 30 fps it will import the file at 24 fps, so I don't think LW is using the preset frame rate, but is reading it from the fbx file. If that's true then Modo is exporting at 30 fps.

RebelHill
08-25-2013, 01:11 PM
Yeah, youre right... I misspoke there. LW does (for me also) open fbx at whatever the fbx fps is tagged as (though not the timeline range).

Sebasvideo
08-25-2013, 01:14 PM
But its NOT video... not yet... not until you render it. Its keys in a 3d animation timeline, and that IS based on time, not fps (unless modos unlike all other apps in that regard). So, assuming modo's not that stupid... then either modo isnt outputting the fractional fps properly to fbx, or LW isnt reading it in right (when I bring stuff in from MB LW picks up the fps just fine, so maybe modo, or maybe just a clash of the 2). So then, the fix is to change your framerate in modo first (which should keep the same timing, by keeping the keys in seconds rather than frame numbers), then export it to fbx, then once in LW, change back to the desired framerate.

The framerate in the Modo project is 23.976, which is what it should be. I'm not going to change it to 30 fps so that it imports at 30 fps in Lightwave and then have to change it to 23.976 to import it into After Effects. It would be more steps for nothing. It's easier to change the frame rate one time in Lightwave upon import.

However, it occurred to me to import the FBX back into Modo, and it's Modo that's messing up the timing, because it imports at 30 fps and with its default frame size of 720x480 (Modo's default frame size puzzles me to this day because it's not D1 pixels, it's square pixels). I don't know why Lightwave imports as 320x200 instead, since I set the default prefs to 1280x536.

RebelHill
08-25-2013, 01:43 PM
If its modo doing the screwy thing then converting to 30fps in modo before export may be your only option. Just may well be that modo "rounds" the framerate for fbx export.

Sebasvideo
08-25-2013, 03:18 PM
If its modo doing the screwy thing then converting to 30fps in modo before export may be your only option. Just may well be that modo "rounds" the framerate for fbx export.

That sounds inviting more problems than I need. If the final composition is going to be 23.976 why would I want to change the frame rate first in Modo, and then in LW? It's faster to change it only in LW upon import. Changing the frame rate in Modo to 30 fps leaves the keyframes at the same time points it was before, but now the keyframes are not at specific frames, but instead at fractional frames like 1188.689. So that's messing up things for no good reason. I'd rather leave it at the original fps, change it in LW and that's it.

stiff paper
08-25-2013, 04:01 PM
That sounds inviting more problems than I need. If the final composition is going to be 23.976 why would I want to change the frame rate first in Modo, and then in LW? It's faster to change it only in LW upon import. Changing the frame rate in Modo to 30 fps leaves the keyframes at the same time points it was before, but now the keyframes are not at specific frames, but instead at fractional frames like 1188.689. So that's messing up things for no good reason. I'd rather leave it at the original fps, change it in LW and that's it.

For goodness' sake...

You would want to change the framerate to 30 in modo because you've said that's all that modo will export correctly. Do you want modo to export correctly or not? If you don't want modo to export correctly then don't set the framerate to 30 in modo. If you do want modo to export correctly then do set the framerate to 30. Because, it seems that 30 is the only framerate that modo exports, so setting the framerate to 30 in modo is the only way to export correctly. And you've strongly implied that you would like modo to export correctly. Which it does. But only at 30fps.

Have I been thorough enough with that?

You correctly note that this will move the keyframes to fractional positions.

However, if you're very lucky (and I won't pretend for a second that it'll be anything other than very lucky) then converting the framerate back to what it should be in LightWave might -and I repeat might- move all your keyframes back to where you want them to be.

I think it's a longshot, but if modo only exports at 30fps then that might be what you're left with...

Also, stop arguing that framerate and time are the same thing in a 3D package. They are not. You are wrong about this. They are, if you like, next to each other, but they are not locked together. Stop digging now and think about it again tomorrow, with a clear head.

Sebasvideo
08-25-2013, 04:08 PM
I think it's pointless to keep arguing about this, as we're not getting anywhere. Like I said, changing the frame rate in Modo and then in Lightwave is useless and pointless, as it's easier to change it just in Lightwave to go back to 23.976. If you don't understand that, then there's no point in wasting more time trying to explain it.

Regardless, my original question was answered: it was Modo that was messing up the FBX export by changing the frame rate to 30 fps when it had been 23.976 in the source scene, therefore moving the position of keyframes, so I should ask in Modo forums if there is a way to make sure Modo sets the FBX export to the scene frame rate and frame size.

stiff paper
08-25-2013, 04:25 PM
If you don't understand that, then there's no point in wasting more time trying to explain it.

Yes. Please don't waste any more of your time.

jburford
08-27-2013, 02:28 AM
I think it's pointless to keep arguing about this, as we're not getting anywhere. Like I said, changing the frame rate in Modo and then in Lightwave is useless and pointless, as it's easier to change it just in Lightwave to go back to 23.976. If you don't understand that, then there's no point in wasting more time trying to explain it.

Regardless, my original question was answered: it was Modo that was messing up the FBX export by changing the frame rate to 30 fps when it had been 23.976 in the source scene, therefore moving the position of keyframes, so I should ask in Modo forums if there is a way to make sure Modo sets the FBX export to the scene frame rate and frame size.


OM (Flippin) G


You can lead a horse to water . . . . . . .

kadri
08-27-2013, 04:08 AM
Somehow this reminded me about the pointless debates over DPI and resolution.
They mostly understand too in the end. But it takes time...