Exporting cloth simulation to Collada results in static cloth instead of a waving one

Question

I hope this thread is not a duplicate since I have been exploring the subject for a few days and found no solution that works for me.

I have to export an animation in .dae format to use in SceneKit/Xcode for iOS. I have created a ghost made of sphere covered with a pinned cloth that waves (I have used wind force field). No armature, the only movement is a waving cloth simulation.

I have found that frames 82-116 are fine to loop them for a ghost idle mode. I tried to export it to .dae (Blender v2.79, default Collada / Better Collada) but the output file always contains static cloth instead of a waving one.

For a few days I have been searching the web to understand what exactly I need to do. I followed https://blenderartists.org/forum/showthread.php?387461-Bake-Cloth-to-game-engine and the workflow I have applied is:

1. Bake the cloth simulation
2. Select cloth and export to .mdd
3. Remove the cloth modifier
4. Select cloth and import the .mdd file

This is the result:

Then, I export to default Collada .dae - but the output file contains static cloth. The same happens when I export to Better Collada .dae - the cloth is still not waving.

I also tried Mesh Cache modifier, following How can I bake the cloth simulation into keyframed vertices or shape keyed vertices? :

1. Bake the cloth simulation
2. Select cloth and export to .mdd
3. Add Mesh Cache modifier

After I hit „Apply”, the cloth freezes. After I hit „Apply as Shape Key”, the cloth freezes and I have basis and singular shape key:

I don’t get it. What am I doing wrong? Is anything missed in my workflow? Is it a problem with export settings?

Answer 1

A collada file supports a static mesh, while an armature may be included to deform the mesh using some animation data. For a mesh deformed from a simulation, you need to use a file that supports an animated mesh, that is, different mesh data is used for each frame.

This can be done in files such as Newtek .mdd, a .pc2 pointcache file or an alembic .abc file. Both mdd and pc2 can be exported using addons available in the standard blender release that just need to be enabled. Alembic should be available in release builds, but as alembic support is compiled into blender, if it isn't available you will need to find a different copy of blender that has it included. Blender can use this exported data in the Mesh Cache Modifier for mdd and pc2 or the Mesh Sequence Cache Modifier for alembic.