Velocity from Direction & Speed (Spherical)

Menu Path : Velocity > [Set/Add] Velocity from Direction & Speed (Spherical)

The Velocity from Direction And Speed (Spherical) Block calculates a velocity for the particle based on a blend ratio between the direction attribute and a spherical vector.

The spherical vector is a normalized vector that goes from a given position, to the current particle position.

The Block then scales the final direction vector by a speed, and composes it with the velocity attribute.

Block compatibility

This Block is compatible with the following Contexts:

• Initialize
• Update

Block settings

Setting	Type	Description
Composition	Enum	(Inspector) Specifies how this Block composes the velocity attribute. The options are: • Set: Overwrites the velocity attribute with the new value. • Add: Adds the new value to the velocity attribute value. • Multiply: Multiplies the velocity attribute value by the new value. • Blend: Interpolates between the velocity attribute value and the new value. You can specify the blend factor between 0 and 1.
Speed Mode	Enum	Specifies how to calculate the speed. The options are: • Constant: Applies a constant speed which you set in the Speed property. • Random: Applies a random speed between Min Speed and Max Speed.

Block properties

Input	Type	Description
Center	Vector3	The position (in the same space as the system) of the center this Block uses to calculate the spherical vector.
Speed	float	The speed multiplier to apply to the direction vector in order to calculate the velocity. This property only appears if you set Speed Mode to Constant.
Min Speed	float	The minimum speed multiplier to apply to the direction vector in order to calculate the velocity. This property only appears if you set Speed Mode to Random.
Max Speed	float	The maximum speed multiplier to apply to the direction vector in order to calculate the velocity. This property only appears if you set Speed Mode to Random.
Blend Direction	float	The blend percentage between the current direction attribute value and the newly calculated direction value.
Blend Velocity	float	The blend percentage between the current direction attribute value and the newly calculated direction value. This property only appears if you set Composition to Blend.