Initial Orientation

– Sets the initial rotation of the particle by aligning the X axis in the direction of the direction of the menu item selected (None, Normal, Object X Y Z, Global X Y Z, Velocity/Hair, Normal-Tangent)

– To visualize better the orientation, one particle is rendered as Suzanne

– In these axamples Suzanne’s x-axis is coloured in relation to initial orientation of the selected item. The axis on the blue mesh indicates the emitter orientation.

– Note: I found some settings work different from as described in 2.79 version documentation. Here I tested using the 2.8 beta.

– None: particle’s x axis owns the same orientation of the Dupli Object or the Global X axis.

Global X

– Normal: particle’s x axis owns the same orientation of the Emitter´s Normal.

Normal

– Object X , Y , Z : Suzanne’s x axis is oriented as one of the Emitter Object axes

Object X
Object  Y
Object  Z

– Global X , Y , Z : Suzanne’s x axis is oriented as one of the Global Axes

Global X
Global Y></div><div class=Global Z

– Velocity/Hair : Here there are two examples to show how increasing X component (Emitter Object , tab Velocity) affects particle’s orientation (and position as we are increasing velocity).

Velocity Hair 1
Velocity Hair 3

– Normal-Tangent: particle’s Y axis is oriented as the emitter’s tangent and particle’s X axis is oriented as emitter´s normal.

Normal Tangetn
Blender Particle Rotation Axis