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It starts May 12, and ends Sept 12. Let's see what you got!
https://polycount.com/discussion/237047/the-brawl²-tournament
[3ds Max 2025] FBX Export with Path deform for Unity
polycounter lvl 3
Hello,
I have animated a vertical shutter with slats using a Path Deform modifier. Upon exporting to FBX the keyframes are lost. As seen in other threads, people found a solution by using collapseTo, to 'bake' the keyframes. Unfortunately, this doesnt seem to work. Currently the only available option (at this time) is to use the file format .abc (Alembic) which seems to work - great!
But, what if the project developers refuse to accept this file type (maybe there are other issues with Alemic and the project asset requirements). Is my only option then to painfully Keyframe the shutter?
All pearls of wisdom are welcome! Thanks!
I have animated a vertical shutter with slats using a Path Deform modifier. Upon exporting to FBX the keyframes are lost. As seen in other threads, people found a solution by using collapseTo, to 'bake' the keyframes. Unfortunately, this doesnt seem to work. Currently the only available option (at this time) is to use the file format .abc (Alembic) which seems to work - great!
But, what if the project developers refuse to accept this file type (maybe there are other issues with Alemic and the project asset requirements). Is my only option then to painfully Keyframe the shutter?
All pearls of wisdom are welcome! Thanks!
Replies
If you want a collapsable animation (which would likely mean a bone or object for each shutter panel), then the path constraint animation controller is the right choice.
Edit: Seems like FBX can export/reference point caches after all. Haven't tried it, though, and no idea if Unity imports it.
https://download.autodesk.com/us/fbx/2013/3ds_Max_FBX_Plug-in_Help/index.html?url=files/GUID-691D1194-AE6E-4EE9-A6A3-F1797D2F3B27.htm,topicNumber=d30e2947
Very broadly speaking, bone animation is usually the preferred method for realtime graphics, but if your shutter is very lowpoly, it might make no real difference.
Many thanks for your response. After exporting an FBX file with a Cache file and re-importing in 3ds Max the kayframes were there! Many thanks, now the Unity developers are looking into it, if we can use it within our Unity project.
Thanks for taking the time, to post your suggestion!
I have found a post on Autodesks Forums with a max file using bones as you suggested, which seems to work pretty well. I hope I can use it as reference.
https://forums.autodesk.com/t5/3ds-max-animation-and-rigging/problems-animating-along-spline-path/td-p/7427833
Note that the important part in step 5 is to replace the XYZ position sub-controller with a path contraint (or use a list controller like seen in the image). He probably started to write that, but then jumped ahead to the bezier float. Or maybe that used to be the default setup of the controllers for the Spline IK back then.
Thanks for the confirmation - If I understand you correctly - should it look something like this?:
On another note, i am also seeing something, that I did not intend for and I have been unsuccessful in figuring it out. The 'Motion Paths' show, that the IK Chain (Green), and Bone (White) Paths do not follow exactly the chosen Spline Path (purple). No one would probably see this detail - but it annoys the hell out of me and for future projects maybe this issue is noticeable...any ideas whats causing this? Thanks once again.
As for the motion paths, how fast is your shutter unrolling? If each straight line is the motion from one frame to the other, then a slower animation would give you more "segments".
As for the points not lying exactly on the spline, that might just be due to geometry. Your bones are straight and can't stretch (both points move at the same speed) so they can't follow each and every curvature perfectly. At least that would be my guess. The distance to the IK goal can shrink, but only by bending the overall chain, which would result in some bones moving away from the spline.
But maybe you could try putting a Normalize Spline modifier on your path and see if that helps.
I have realised, the shutter slats dont really behave like that. The slats are attachd to a tube, similar to wrapping toilet paper back on a roll. If you have the roll and the paper, to roll the paper back on to the tube, the first sheets stay on the cardboard tube and the others are added as it is rolled back up.
We already have a spline taking the slats to the motorised roller, how can we get the slats from the spline, to the roller and ensure the following slats continue to roll up correctly?
Can anyone steer me in the right direction. The keys need to be collapsable, as it needs to be exported to Unity using FBX.
Many thanks
As you mentioned the toilet paper roll, there's an old trick where you slighty rotate the object or the rotate gizmo (relative to each other) and with the limit function, you can roll up a straight piece of geometry into a spiral. Maybe you can do something with that. (Edit: with the Bend modifier.)
Perhaps something with the new Spline Booleans and normalizing the result? Basically rotating the open end of the spiral into an animated subtracting shape that moves closer to the center and continuing straight down from there. But that probably would lead to the vertices jumping around.
In either of the two latter options, you'd have to animate some things/parameters manually and probably eyeball it (you probably could calculate it as well if you really wanted to, but I wouldn't even attempt that).
Edit: In your image, it looks like you conneced the spiral at the wrong end, unless that part is just for setup and later hidden, and the spriral should turn the other way round (counterclockwise). The trick/problem is to have the transition to the unattached straight bit move inwards or outwards from the center over time at the right rate (which will also change speed if the cylinder rotates at constant speed).
thanks for getting back in touch! Upto now, I have not been able to resolve my issue.
You mentioned:
As you mentioned the toilet paper roll, there's an old trick where you slighty rotate the object or the rotate gizmo (relative to each other) and with the limit function, you can roll up a straight piece of geometry into a spiral. Maybe you can do something with that.
I don't understand your explanation. What modifier/constraint is being used?
Physical simulation, I would like to play with that, unfortunately I do not have the resources at the moment to investigate this new topic.
Regarding the spline, the shutters starting position is closed and animates open. The slat should come up (vertically, in reality being pulled from the rotating cylinder), then bend along the spline and attach to the clockwise rotating cylinder. In reality, the slat moves with the cylinder upon contact. This repeats for the other slats, once the cylinder is full, the slats will fold onto another, just like rolling up toilet paper. Upon completing the roll-up, the last slat is the furtherst from the center.
A clockwise rotating cylinder will result in a counterclockwise wound spiral.