Exporting keyed blend shape anims for SceneKit with FBX_DAE fails

[Anonymous]

We're using Maya to produce some characters for use in Apple's SceneKit.  Our workflow is to export as .dae (COLLADA) files with Maya 2018.2's built-in DAE_FBX exporter, then load into SceneKit in Xcode (9.3).  Our basic models and blend shapes are exported correctly for the most part and are directly usable in SceneKit.  -- this part is great.  However, any keyed blend shape animations do not load.  All the animations on the transform that I've tested work fine.

I created a new project and isolated this down to the simplest possible scenario.  I created a very simplistic Maya project with 1  blend shape.  Then I did a simple animation on that blend shape.  Then exported to dae.  Then FAIL.

My software versions are:

- Maya 2018.2 (Cut ID: 201711281015-8e846c9074)

- Xcode 9.3 (9E145)

- macOS High Sierra 10.13.4

- iOS 11.3.1

On the Maya side of things, I've tried several variations on the creation/export process:

- Tried "remove single key" checkbox (with and without)

- Tried "bake animation" setting in export window

- Tried checking and unchecking "Deformed models" and "blend shapes"

- Under the DAE_FBX export window, I've tried with and without "Single Matrix" checked.  Regardless of this setting, the transform animations work either way, but the blend shape animations do not.

I eventually thought this would probably be a SceneKit bug on Apple's side, so I filed a bug report and a case for developer tech support.  After some back and forth, they came back stating that it is a bug in Maya's exporter.  After reading through their response as well as the COLLADA spec and doing numerous other tests, I'm inclined to agree.

They wrote:

cube-blend.dae contains a blend shape animation but the target syntax is incorrect: pCube2-lib-morph-weights(Weight_0_0). This is an exporter issue (we tried to import this file in Modo [can’t open it] and Cinema4D [loads correctly but with no animation]).

The COLLADA spec seems to indicate that the target name having parenthesis for any purpose other than array/range index is invalid.

At this point I'm really hoping for a workaround.  Or a full fix.  Or any sort of workflow that actually works.

I tried importing into Cinema4D and had the same result as the Apple tester.  I also tried Khronos group's OpenCOLLADA COLLADAMaya exporter with Maya 2017, but that has other issues.  I've tried with 2017 Update 5 and 2018.2.  Trying 2018.3 in a moment.

Does anyone have a solution or a workflow that is usable?

The full demo Maya project, demo Xcode project, and descriptive videos are here:

https://bitbucket.org/drewster77/scenekitimportedanimtest/src/master/

I'm also attaching the Maya project and the generated .dae file.

Thank you!

EDIT:

I'm having technical issues uploading the files, so I'll link them here for now:

cube-blend.ma

cube-blend.dae

cube-blend.mov

[Anonymous]

We're using Maya to produce some characters for use in Apple's SceneKit.  Our workflow is to export as .dae (COLLADA) files with Maya 2018.2's built-in DAE_FBX exporter, then load into SceneKit in Xcode (9.3).  Our basic models and blend shapes are exported correctly for the most part and are directly usable in SceneKit.  -- this part is great.  However, any keyed blend shape animations do not load.  All the animations on the transform that I've tested work fine.

I created a new project and isolated this down to the simplest possible scenario.  I created a very simplistic Maya project with 1  blend shape.  Then I did a simple animation on that blend shape.  Then exported to dae.  Then FAIL.

My software versions are:

- Maya 2018.2 (Cut ID: 201711281015-8e846c9074)

- Xcode 9.3 (9E145)

- macOS High Sierra 10.13.4

- iOS 11.3.1

On the Maya side of things, I've tried several variations on the creation/export process:

- Tried "remove single key" checkbox (with and without)

- Tried "bake animation" setting in export window

- Tried checking and unchecking "Deformed models" and "blend shapes"

- Under the DAE_FBX export window, I've tried with and without "Single Matrix" checked.  Regardless of this setting, the transform animations work either way, but the blend shape animations do not.

I eventually thought this would probably be a SceneKit bug on Apple's side, so I filed a bug report and a case for developer tech support.  After some back and forth, they came back stating that it is a bug in Maya's exporter.  After reading through their response as well as the COLLADA spec and doing numerous other tests, I'm inclined to agree.

They wrote:

cube-blend.dae contains a blend shape animation but the target syntax is incorrect: pCube2-lib-morph-weights(Weight_0_0). This is an exporter issue (we tried to import this file in Modo [can’t open it] and Cinema4D [loads correctly but with no animation]).

The COLLADA spec seems to indicate that the target name having parenthesis for any purpose other than array/range index is invalid.

At this point I'm really hoping for a workaround.  Or a full fix.  Or any sort of workflow that actually works.

I tried importing into Cinema4D and had the same result as the tester.  I also tried Khronos group's OpenCOLLADA COLLADAMaya exporter with Maya 2017, but that has other issues.

Does anyone have a solution or a workflow that is usable?

The full demo Maya project, demo Xcode project, and descriptive videos are here:

https://bitbucket.org/drewster77/scenekitimportedanimtest/src/master/

I'm also attaching the Maya project and the generated .dae file.

Thank you!

[sean.heasley]

Hi @Anonymous

Thanks for the in depth post on this!

While I don't have SceneKit to personally test this, I'm going to pass this along to our developers so they can take a look at it and let me know if this is indeed and issue that needs to be fixed and/or if there's a workaround available.

[Anonymous]

Awesome - I really appreciate that.

[Anonymous]

Hi Sean,

Do you have any update from developers on this item?  Or is there a better way to get it the needed attention?

Thank you so much,

Andrew

[sean.heasley]

Hi @Anonymous

No update yet. I do have it logged with our development team as an issue and when they get back to me with an update I'll be sure to let you know!

[mattGFNMV]

3 months later... facing the same issue. Any update on this?

[sean.heasley]

Hi @mattGFNMV

The devs have reproduced this and are working on it but I can't say which update or when a fix will be implemented.

I just ask that you please be patient and keep an eye out for future updates/releases of Maya and their patch notes so you'll know the second we officially have its solved and release a fix!

[Anonymous]

Any updates from the Devs? I am going through the exact issue!

[sean.heasley]

Hi @Anonymous

At the moment there aren't any changes I can disclose but I'll update when that changes.

[Anonymous]

Same issue. Note to all: in my experience, the developers don't really fix many things. Every person for themselves I guess.