The Birth Objects operator allows you to convert scene objects into particles.
Object list: the list of input objects which will be converted into particles.
Inherit object geometry: controls whether the meshes of input objects will be assigned to corresponding particles.
When “inherit object geometry” is disabled, only object transforms will be transferred to birthed particles. This can provide a significant speedup if the input objects have high resolution meshes, but you do not need those meshes to be assigned to the new particles (for example, if you want to align particles to objects but don’t need those particles to inherit the meshes).
Split group members: if an input object is a group head, enabling this setting will convert its constituent members into particles.
Split object elements: if an input object mesh has multiple sub-elements, enabling this setting will split them into multiple particles.
Preserve normals: when enabled, existing surface normals will be made explicit and preserved during the operation.
Save element index: when enabled, elements split from a source mesh will be assigned a 0-based index value that will carry over onto the corresponding particles as a custom float value.
Element index channel: the custom float channel to assign the element index value.
By enabling “save element index” in a Birth Objects operator, and enabling “match elements by ID” in a tyParticleSkin modifier (which uses the particles from that flow as its source particles), you can force elements of a skinned mesh to be weighted only by particles with a matching element index. This avoids scenarios where the proximity of source particles causes nearby mesh elements to be weighted by the wrong particles. When both of the aforementioned options are enabled, each element of a source mesh controlled by a tyParticleSkin modifier will only be weighted by the particles that were created by it in a Birth Objects operator.
Center all pivots: centers the pivots of extracted meshes.
Update Cache: click this to manually update the internal cache which holds mesh data for all input objects.
Auto update: controls whether changes to input objects will automatically update the operator’s internal mesh cache.
Hide after adding: controls whether objects will be hidden in the scene after adding them to the listbox.
The “hide after adding” setting is a sticky setting (remembered between operators and Max sessions) that will remain checked/unchecked depending on which state you leave it in last.
Start: the start frame at which particles will be birthed.
End enabled: controls whether particles should be birthed over a range of frames.
End: the end frame at which particles will be birthed.
If particles leave the event which contains the Birth Objects operator, their animation will no longer be updated by the Birth Objects operator.
Inherit position: particles will inherit the position changes of the scene object they reference.
Inherit rotation: particles will inherit the rotation changes of the scene object they reference.
Inherit scale: particles will inherit the scale changes of the scene object they reference.
Inherit velocity: particles will inherit the linear/angular momentum of the scene objects they reference (note: the velocities will not be integrated until the particles leave the event).
None: no material override will be assigned to render instances of the born particles.
Inherit from object: the material override for render instances of born particles will be taken from the scene object they are referencing.
Save birth index: controls whether the 0-based index of new particles birthed by the operator will be saved to a particle’s custom data channel.
Channel: sets the data channel the birth index will be saved to.