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Parameter

Description

Focus Angle

The amount to rotate, in degrees from Y axis. (0 = straight up, 90 = Horizontal, 180 = straight down).

Focus Azimuth

The amount to rotate the new axis about the Y axis. (0/360 = North, 90 = West, 180 = South, 270).

Focus Camera Dir

Set focus direction to face camera. Amount can be scaled from 0 to 1.

Focus Gravity Dir

Force the focus direction to world negative gravity direction (usually world +Z), ignoring emitter orientation.

Focus Rotates Emitter

If true, changing the focus direction with the above parameters also rotates the orientation of the Offset parameters. If false, Offset vectors remain in emitter orientation.

Emit Offset Dir

If true, change each particles emission direction to be aligned with its offset from the origin.

Emit Angle

The angle deviation of an emitted particle from the focus axis (default local +Y). (0 = +Y straight up, 90 = comes out horizontal to the emitter, 180 = -Y straight down).
This is the maximum angle from the focus. The Random sub-parameter controls the minimum angle.

Examples:

• To emit in all directions, set Emit Angle = 180, Random = 1.
• To emit in the top hemisphere, set Emit Angle = 90, Random = 1.
• To emit in a horizontal circle, set Emit Angle = 90, Random = 0.

Facing

Applies only to 2D particles, Determine how the sprite is oriented in space. Texture orientation is further modified by rotational parameters:

• Camera: Faces the  viewer, texture X&Y aligned with screen X&Y.
In this mode only, particles are assumed to represent spherical objects, are are lit accordingly (see Curvature below). In all other modes, particles are lit as flat polygons.
• CameraX: Rotates about local Y axis only, to face camera as much as possible.
• Free: Rotates freely in 3D. (Remember to give it some rotation; the default orientation is equal to the emitter's).
• Velocity: Faces direction of movement.
• Water: Faces upward, moved and aligned to nearest water plane.
• Terrain: Faces upward, moved and aligned to nearest terrain location.
• Decal: Renders the particle as an actual deferred decal, projected onto the nearest surface. (The Thickness parameter controls the projection depth.) (Only works with Materials, does not work with textures)

Orient To Velocity

Forces Texture X axis aligned to direction of movement. Rotation parameters can rotate it further.

Curvature

For Facing = Camera particles, sets how far the vertex normals are bent into a spherical shape, which affects lighting.
0 = flat, lit like a polygon. 1 = bent into an (almost) hemispherical shape, lit like a sphere, which is the default.

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