This page provides information on V-Ray Attributes that can be added to particles.

Overview

The V-Ray Additional Attributes can be added to particles. Adding these attributes will add new settings in the Extra VRay Attributes rollout.

UI  Path

 

||Select particles|| > Attribute Editor >  Attributes menu > VRay > (select attribute set)

 

 

Per-Particle Attribute Export

 

This group allows to specify which per-particle attributes you want to be translated by V-Ray. These attributes are then available for use by the particleSampler node.

 

Add to node:

vray addAttributesFromGroup "nParticleShape1" "vray_particle_export_attributes" 1;

Attributes:

vrayPPExportAcceleration
vrayPPExportAge
vrayPPExportLifespan
vrayPPExportRGB
vrayPPExportOpacity
vrayPPExportEmission
vrayPPExportScalar1
vrayPPExportScalar2
vrayPPExportScalar3
vrayPPExportScalar4
vrayPPExportScalar5
vrayPPExportVector1
vrayPPExportVector2
vrayPPExportVector3
vrayPPExportVector4
vrayPPExportVector5

 

 

 

 

Sprite Orient

 

Sprite Orient – Sets the orientation of the billboards when the particle rendering type is set to Sprite. The possible options for this parameter are Towards camera center and Parallel to camera's image plane.


Add to node:

vray addAttributesFromGroup "nParticleShape1" "vray_sprite_orient" 1;

Attributes:

vraySpriteOrient

 



Point Size

 

Point size pp – Render the points using the per particle radius instead of the constant point size.

Point size world – By default when the particle rendering type is set to Point, the size is given in pixels on the screen. If this option is checked, the point size is assumed to be in world space.

Point size from radius – Since the point size can be given only as an integer, this attribute specifies that it should be taken from the radius which can be a floating point number.


Add to node:

vray addAttributesFromGroup "nParticleShape1" "vray_point_size" 1;

Attributes:

vrayPointSizePP
vrayPointSizeWorld
vrayPointSizeRadius

 

 

Cache Interpolation

Use interpolated cache – This attribute is available only with nParticle and is intended as a workaround when using nCache. In this case, Maya does not interpolate the particle positions between cache frames. The recommended workflow is to always have cache for frame times that V-Ray renders. If this is not executed properly, V-Ray tries to find information about the cache and uses the velocity to estimate the next particle position. If this option is on, V-Ray samples the cache where it's available and interpolates the data. This way the end position of one frame better matches the start position of the next frame. This process can be much slower, and requires all dynamics on the scene to be cached!


 Add to node:

vray addAttributesFromGroup "nParticleShape1" "vray_particle_cache" 1;

Attributes:

vrayInterpolatedCache

 

 

 

 

Instancer Overrides

 

This group is used with Instancer nodes, in order to pass per particle attributes that can override attributes of the instanced geometry.

 

Instancer PP Times – The name of a PP attribute of type double, that overrides the frame times of the instanced object. This can be used for example to change frame time with V-Ray proxy nodes.

Instancer PP Object IDs – The name of a PP attribute of type double, that overrides the Object ID of the instanced geometry object.

PP Primary Visibilities – The name of a PP attribute of type double, that sets the "Primary Visibility" flag of the instanced geometry object.

PP User Float Attribute 1/2/3 – The name of a PP attribute of type double, that is added to the user scalar attributes of the instanced geometry object. The user attribute name is the same as the PP attribute name.

PP User Vector Attribute 1/2/3 – The name of a PP attribute of type vector, that is added to the user color attributes of the instanced geometry object. The user attribute name is the same as the PP attribute name.