Particle Render Type
This attribute can be used to override the render type set in the particle shape.
| Value | Description |
|---|---|
| Inherit | Use the render type set in the particle shape |
| Points | Render using 3Delight's lightweight primitive |
| Spheres | Render using 3Delight's spheres |
| Streak | Render as streaks (lines) |
| Disk | Render as 3Delight's disk |
| Blobby | Render as 3Delight's blobbies |
Particle Size Space
This attribute is used to specify the space in which the size of the particles is expressed. Available values are summerized in the table below.
| Value | Description |
|---|---|
Raster Space | The particle size will be taken as pixels. The particle size will remain the same, even if the distance between the camera and the particle system changes. |
Object Space | The particle size is expressed in the object space. Scale transforms affecting the particle system will influence the particle size. This is the default. |
World Space | The particle size is expressed in world space. |
Particle Size Override
When this attribute exists, it defines the size of the particles, overriding what is defined in the attached particle system shape. This can be useful when the particle size needs to be expressed in object space or world space, since the particle shape "Point Size" attribute has a minimum of 1, which can be too large for size in object or world space.
Paticle Size Scale
This attribute specifies a scaling facotr that is applied to per particle or per system size value. The default scale factor is ‘1.0’.
Render As Volumes In DSMs
Particles rendered into a deep shadow map will appear as flat objects. Thus, when viewed from a different location than the light, the half closer to the light will not be shadowed while the other half will have self-shadowing. When this attribute is on, particles will be exported with a thickness equivalent to the width, height or radius or the particle, which should generally be enough to work around the shadowing problem. Note that this only has effect when rendering deep shadow maps, and only when the "Volume Interpretation" attribute of a Light Attribute Node is set to ‘continuous’.
Render nCloth as Particles
When this attribute is on, any attached nCloth shape will be rendered as a par- ticle system. The nCloth shape’s "Thickness" and "Self Collide Width Scale" attributes are used to compute the particle size. This attribute is off by default.
Per Particle Color as Surface Color
When this attribute is on, the "rgbPP" particle system attribute will be output in the surface color primitive variable (‘Cs’). Turning off this attribute will output the "rgbPP" data as a ‘rgbPP’ primitive variable. See Color for more details on how Cs is used with hypershade shaders and photons. This attribute is off by default.
Typical Particle System Attributes / variables
This panel offers the possibility of exporting particle attributes as primitive parameters, giving the opportunity to attached RenderMan shaders to use that data for their computations. The selected attributes will be exported given that they have been previously defined for the particle system. Here is an overview on how to use the content of this panel:
- The left panel lists usual particle attributes. Select the ones that are to be exported and click the "Add >>" button.
The right panel lists attributes that will be exported. Selects the ones that are not required to be exported anymore and click the "<< Remove" button.
Additionally, the text field at the bottom of the panel can be used to add custom particle attributes. Several attributes can be listed, as long as they are separated by spaces. All attributes listed in the text field will be exported as primitive parameters.
This panel is irrelevant if the attached object is not a particle shape or a nCloth shape. By default, all particle systems are exported with the following primitive variables: colorRed, colorGreen, colorBlue, rgbPP, opacity, opacityPP, incandescence, incandescencePP.