.. _bpy.types.ParticleInstanceModifier: ************************** Particle Instance Modifier ************************** When a *Particle Instance* modifier is added to an object, the mesh of this object will be duplicated at the location of the particles of the selected *Particle System*. This means that to use this modifier you must have at least one other object that has a :doc:`Particles System ` on it. Because of the correlation in which the *Particle Instance* modifier is influenced by the underlying particle systems on other objects, some of the apparent effects generated by the modifier can look and act vastly different, depending on the underlying settings of the particle systems it is associated with. This is worth taking account of when it seems that the *Particle Instance* modifier settings do not return the expected results. Options ======= .. figure:: /images/modeling_modifiers_simulate_particle-instance_panel.png Particle Instance Modifier. Object The name of an object which has a particle system associated with it. Particle System The *Particle System* field is used to select which particle system to apply the *Particle Instance* modifier to, when the mesh which has the particle system on it has more than one of these. Create From ----------- Normal When selected, the modifier will use the regular (parents) particles to duplicate the mesh of the modified object. Children When selected, the modifier will use the :doc:`children ` particles to duplicate the mesh of the object being modified. Size Scale the instanced mesh by the particle size attribute. When this is disabled, all the copies appear the same size as the origin. See the particle system's :doc:`Render ` and :doc:`Children ` panels for particle's size options. Show Particles When ------------------- Unborn When selected, the modifier will use the unborn particles to duplicate the mesh of the modified object. Alive When selected, the modifier will use the alive particles to duplicate the mesh of the object being modified. Dead When selected, the modifier will use the dead particles to duplicate the mesh of the modified object. Further Options --------------- Space World, Local Use :term:`World Space`, or :term:`Local Space` of the object (that the particle system is assigned to). Amount The percentage of particles to be used. Allows you to randomly skip particles to adjust the amount of particles. Offset Specifies the "offset" which of the particles will be skipped. Allows you to avoid overlapping of the used particles, when the same particle system is used in multiple modifier instances. Rotation Axis Specify which pole axis to use for the rotation. X, Y, Z Using Paths ----------- By default, the instances are placed depending on the particles position in the current frame. By enabling this option, you can select the position along the particles path regardless of the current frame. You can adjust the particles path (using the *Path* visualization type) on the :doc:`Render ` panel of the Particles System tab. .. note:: The particles system must be :doc:`baked `, except Hair and Keyed physics. Create Along Paths This option tries to make the underlying mesh object of the modifier deform its mesh shape in such a way as to try and match the path the particles move along (or hair strands) of the system associated with it. Keep Shape Enabling this prevents the object from being deformed and places it on the path according to the *Position* value. Position Specify what percentage of the path the object fills, or position on the path if the *Keep Shape* option is enabled. Rotation Specifies the rotation around the path. Random Scales the Position/Rotation value of each instance a random value. Custom Data Layers ------------------ These fields allows you to select vertex color layers, which will be filled with colors based on the particles information. These vertex color layers can be used, for example, in a shader to add variance to a material. Index Layer A vertex color layer for values based on the particles index. Value Layer A vertex color layer for random per-particle values. Examples ======== .. figure:: /images/modeling_modifiers_simulate_particle-instance_split-plane.jpg :width: 600px Particle Instance modifier example. The render above shows a single plane mesh object assigned to two different vertex groups and each of those vertex groups is assigned to a separate and independent particle system, with each particle system being assigned to a different Particle Instance modifier. In the case shown the Particle Instance modifiers are a sphere and a cube. See `example blend-file `__. .. figure:: /images/modeling_modifiers_simulate_particle-instance_create-along-paths.jpg :width: 600px Create Along Path example. In this example, a single *Keyed* particle travels through four points (green planes), on an elliptical path. The *Particle Instance* modifier is added to a cylinder object and then associated with that *Keyed* particle system. When the *Create Along Paths* is activated, instead of the cylinder location just following the position of the particle, the cylinder mesh is fitted to the shape of the path followed by the particle. The mesh geometry of the object which is deformed can have an impact on how well the deformation is carried out. In the case of the cylinder, it has many loop cuts along its length so that it can bend at those points to deform along the particle path. The Particle Instance modifier *Create Along Paths* works for hair (strand) particles as well as with keyed particles. In this case the mesh of the Particle Instance modifier will follow the length and profile of the hair strands paths. .. note:: Strands when they are generated instantly die when created so for the *Create Along Paths* checkbox to be of any use, you must also have the *Dead* checkbox activated.