Problem summary
Particles generated via a surface emitter on moving replications randomly generates particles incorrectly. These particles appear to be frozen/not inherit velocity from the source, or be detached from the surface entirely.
Customer reported version
modo.12.0v1
Customer reported platform
windows10
Steps to reproduce
1) Open Modo.
2) Select File > open and open the attached scene.
3) Select the animate layout and press "play" to view the particle system. Result: While most of the particles follow the replicated surfaces, some particles appear "stuck" and do not move on certain frames.
Workaround
1) Create a new mesh item.
2) Add a merge meshes operator to this mesh item.
3) Add the replicator as a source to the merge mesh operator.
4) Right click the mesh and select "Bake to Alembic." Export the file.
5) Select File > import and import the alembic file from step 4. Make sure "Combine Transform and Mesh Names" is disabled, and "Import All Frames" is enabled.
6) Select the Surface Emitter and change the source to the imported alembic file. Result: The particles should follow the surfaces on every frame.
Reproduced by support
This bug has been reproduced in:
15.2v1 - Windows 10
15.1v1 - Windows 10
15.0v1 - Windows 10
14.2v1 - Windows 10
14.1v1 - Windows 10
14.0v1 - Windows 10
13.0v1 - Windows 10
12.2v1 - Windows 10, OSX 10.13.5
12.1v2 - Windows 10
12.0v1 - Windows 10
Note: The merge meshes operator is not available prior to Modo 12.
Earliest version tested
12.0v1 - Windows 10, OSX 10.13.5 - This issue appears to be in all versions where the "Merge Meshes" operator is available.
Expected behaviour
Particles should generate on instances/replications normally/as if they were regular items.
Actual behaviour
Particles can occasionally be abnormally generated on replications.