Path Deform for Animation Export

(Nuaire) #1

Hi there, is there any way of getting the Path Deform (WSM) modifier in 3DS Max to work with exporting animations for Sketchfab?

I have some arrows that need to follow a path through a ventilation unit but the export seems to disable the animation given by the path deform modifier.

Cant seem to find an answer on the forum.
A previous question with gears and a chain was left unresolved on here.

[edit] I realise I can use a ‘path constraint’ but a path deform would be a much nice result so I can have a long arrow curving around the path rather than a rigid object simple moving.


We probably can’t directly support modifiers specific to 3ds Max - they are probably not exported correctly to formats like FBX. Are you able to bake this animation?

(Nuaire) #3

[edit] although this works for a single fbx export, using the game exporter to split the animation removes the animation in the morpher modifier :frowning: )

Yeah seems its just the .fbx format that doesn’t like WSM modifiers.
Annoyingly baking a path deform modifier is remarkably difficult without script intervention.

It seems the only way to do it is shown in this Youtube video which uses snapshot and the morpher modifier in conjunction with a script they have kindly pasted into the video info section.

I used this method and it works perfectly.
Just need to watch up until 2:30

After you have baked the animation you can delete all the snapshots but you must keep the morpher modifier.

Hopefully this will help others :slight_smile:


Nice, thanks for sharing the solution!

(Fat Of The Land) #5

You can always go for an alembic export if the size allows you. If you really wanna go fbx you can still use the path constraint method but u have to rig the arrow with a spline IK chain and path constraint the controllers(dummies) to your path starting with the master.You have to manually move the other controllers on the path. Some Axis flipps might occur.
Hope this helps

(Fat Of The Land) #6

Here’s an example of an alembic export with tons of 3ds max animated modifiers ( slice plane, path deform, lathe,bendings ,FFD etc) .

(Nuaire) #7

Ah never heard of Alembic. I shall investigate that too.
Thank very much.

(Fat Of The Land) #8

The big drawback of using alembic in most cases is the size of the file and the fact that you don t have material channels(u have to group in the same object the geometry which shares the same material).
I might be wrong about the whole material business

(Nuaire) #9

Well I’m really disappointed.
Although the method I posted works when just exporting it to FBX format in the regular way, for some reason, using the game exporter (to the break the animation into named sections) stops it working again. If I want to split the animation into sections (this is imperative for my model) then the morpher modifier stops working.
When you import teh fbx back into max, the morpher mod is still there but there is no animation in the target values anymore meaning it’s just a static model. >:frowning:

I spent sooo long trying to get it to work yesterday and I’m sad to say it beat me.

The limitations the alembic format gives means that is sadly also not an option.

Basically I wanted nice long airflow arrows winding there way around the inside of one of my ventilation units but I can’t do that when using the game exporter. I’ll have to settle for the less appealing multiple small short arrows and a path constraint :frowning:


Have you tried exporting each animation to a separate FBX file?

(Nuaire) #11

Ah I haven’t. As it says it’s still experimental I’m assuming this is a new feature? I haven’t seen this posted before.

I’ll have a go.

Do you know if ultimately this means the user is downloading 7 times the file size if I have 6 animations? or do the animations just get incorporated into the master file? My scenes are kept as small as possible as they tend to get quite complex and our reps only have a limited data bundle for their phones. The fact the models have to be downloaded each time the viewer is watched means this method will cause a problem if the download size is also multiplied.

Thanks for that. I’ll give it a test.


There should be only one FBX file with all your meshes, and then the other FBX files only contain animation data, not meshes, so they should be quite small.

@waleguene implemented this feature last year, so maybe he can share more on the topic.

(Mrgrotey) #13

I would appreciate somewhat of a walkthrough if anyone has the time. If I use the game exporter in 3DS max and tell it to save in multiple clip files each file has a very similar size to each other and they are all pretty much the same size as the overall file i.e. around 14mb. Every file has meshes included.