The Shape operator allows you to assign meshes to particles.
Select an existing item in the shape list to modify its properties.
As particles enter the operator, the shape they are assigned depends on the frequency values of shapes in the list. For example, if one shape has a frequency of 10%, and a second shape has a frequency of 90%, there will be a 10% chance that particles will be assigned the first shape, and a 90% chance that particles will be assigned the second shape.
You do not need to ensure that all shape frequencies add up to 100%. Their values will be normalized automatically if they do not all add up to 100%.
Override scale: controls whether to override the scale of particles which are assigned the shape.
Scale %: the scale override.
2D: controls whether the shape will be selected from a list of preset 2D meshes.
3D: controls whether the shape will be selected from a list of preset 3D meshes.
Reference object: controls whether the shape will be referenced from a scene object in the scene.
.vrmesh file: controls whether the shape will be loaded from an existing .vrmesh file.
When selecting a group as the reference object, make sure you select the bounding group head object, not a member of the group itself. The group head is denoted in the viewport as a colored bounding box around the group members, and can be displayed by selecting the closed group and choosing Group->Open from the 3ds Max Group menu.
Split mesh elements: if the shape mesh has child elements, the assigned shape will be a random child element of the mesh.
Center pivots: moves the shape’s particle offset to its center.
Material ID Override: overrides the material ID of the particles the shape is assigned to with a random material ID within a range of specified values.
Min/Max: the min/max range of potential material IDs.
Animated Geometry: controls whether animated deformations of the shape will carry over onto particles that are assigned the shape.
Update in render only: controls whether animated deformations of the shape are only updated at rendertime. This allows for faster viewport updates.
Animation sync: controls the offset timing of animated deformations.
Event age: the start frame of the animation will be synced to the event age of the particle.
Particle age: the start frame of the animation will be synced to the age of the particle.
Frame: the start frame of the animation will be synced to the current frame of the timeline.
Start frame: the start frame of the animation to reference.
End frame: the end frame of the animation to reference.
Rand offset: the per-particle random starting offset within the start/end range of the animation.
Loop: controls whether the animation will loop back to the start frame once the end frame is reached, during sync.
None: no material override will be assigned to render instances of this shape.
Inherit from reference: the material override for render instances of this shape will be taken from the scene object it is referencing.
Scene Material: the material override for render instances of this shape will be the specified material.
.mat file: the material override for render instances of this shape will be the first material present in the specified material file.