Rendering Particles

Software Rendered Particles

These particles DO NOT render properly using the Maya Hardware Renderer.

You must use Maya Software renderer. Don't forget to change it to Production Quality.

Types:

Blobby Surface (solid metaballs) - use any surface material

Cloud (blurred fuzzy metaballs) - use Particle Cloud material

Tubes - use Particle Cloud material

 

The shader attributes:

Threshold works with Particle Size - Radius - adjust them both

Threshold controls surface blending between Cloud or Blobby Surface spheres.

Maya Reference

To make the clouds:

1. Assign ramps for rgbPP, opacityPP and incandPP

2. Apply the Particle Cloud material and assigned a crater for the Blob map

3. For this crater, increase the color gain to white with values > HSV : 0,0,3 (0,0,1 is default)

4. Change colors, play with density, transparency, etc.


FROM Maya Reference Materials on Particle Cloud Material:

Color
The basic color of the particle cloud. The default color is a green-blue.

Transparency
Controls how much you can see through the particle cloud. It is a color, so that you can control the transparency of the red, green, and blue channels separately. To make the cloud more opaque, set transparency to be darker. To make the cloud more transparent, set transparency to be brighter.

Incandescence
Use Incandescence to make the particle cloud brighter, as though it were a light source. By default, Incandescence is black, meaning no glow is added.

Note:
When Incandescence is turned on, although the particle cloud glows, it does not cast light on other objects in the scene.

Life Color
Determines the color at a particular time in the life of the particle. You can use the Particle Sampler Info node to animate this attribute over a particle’s lifetime.

Life Transparency
Determines the transparency at a particular time in the life of the particle.You can use the Particle Sampler Info node to animate this attribute over a particle’s lifetime.

Life Incandescence
Determines the incandescence at a particular time in the life of the particle.You can use the Particle Sampler Info node to animate this attribute over a particle’s lifetime.

Note:
Life Color, Life Transparency, and Life Incandescence are driven by the particle age (the texture defines color, transparency, and incandescence, all of which get their UV information from the particleSamplerInfo utility node). The particleSamplerInfo utility node is created automatically at the time the texture is created.

Glow Intensity
Controls how much of a halo-like glow effect is added to the particle cloud. This glow effect is added as a post-process, after the rendering is completed. Glow Intensity is zero by default, meaning that no glow is added.

Transparency
Density

Similar to transparency; it controls how dense the cloud of particles appears to be, and therefore how much of the background can be seen through it. Increase this value to make the cloud more dense.

Blob Map
Specifies a scaling factor applied to the transparency of the particle cloud. You can connect a 3d texture to it in order to give some internal texture or shape to the cloud beyond what it gets from the particles.

Roundness
Controls the noise’s irregularity. The smaller the value, the less rounded the shape.

Translucence
Specifies a scaling factor for density that is used only to compute shadows. The larger the translucence value, the more light penetrates. The formula is:

density * (1 - translucence)

Built-in Noise
Noise

Controls the jitteriness within the particle cloud. If it is set to zero, the cloud looks very smooth and uniform throughout. As the amount of noise increases, the cloud appears noisier, like static on a television screen. Noise is set to 0.75, by default.

Noise Freq
Determines the size of the noise artifacts when Noise is turned on. Higher values of Noise Frequency produce smaller, finer artifacts, and lower values produce larger, coarser artifacts. If Noise Frequency is set to zero, that is the same as turning Noise off.

Noise Aspect
Controls the distribution of the noise (when Noise is turned on). It is zero by default, meaning the noise is equally distributed in X and Y. Positive values make the noise run perpendicular to the particle’s path. Negative values make the noise run more parallel to the path.

Noise Anim Rate
Specifies a scaling factor that controls the rate of built-in noise changes during an animation.

Solid Core Size
Determines the size of the core, which is the area where the particle is opaque.

Surface Shading Properties
Diffuse Coeff

Controls how much of the light in the scene is reflected from the particles. Most materials absorb some of the light falling on them, and scatter the rest.

The default value is 0.0. If you set this to 1.0, all the light falling on the material is reflected. Use a high value when creating dense clouds. If you set this to 0.0 (the minimum), no light is reflected and no surface shading occurs.

The surface color is modulated by the transparency. This value can be greater than 1.0, so the surface property can still appear even when the material is transparent.

Surface Color
Specifies the basic color of the particle cloud surface (as opposed to the inside of the cloud). Diffuse Coeff must be set to a value greater than 0 to enable this option.

Bump Mapping
Makes the surface appear rough or bumpy by altering surface normals (during rendering) according to the intensity of the pixels in the bump map texture. Diffuse Coeff must be set to a value greater than 0 to enable this option. (A bump map does not actually alter the surface. A silhouette of the surface appears smooth).

Translucence Coeff
Simulates the way light diffusely penetrates through translucent objects. This means that when light shines on one side of the object, the other side is partially illuminated. You can use this to create effects such as clouds, fur, hair, marble, jade, wax, paper, leaves, and so on. If you set Translucence Coeff to 0 (the default), no light shows through the object. If you set Translucence Coeff to 1, all the light shows through. Diffuse Coeff must be set to a value greater than 0 to enable this option.

Surface Shading Shadow
Determines if the surface shading is combined with the pre-illumination, which contains shadows, if enabled (see the Filter Radius attribute description next). Diffuse Coeff must be set to a value greater than 0 to enable this option.

Pre-illumination Controls
Filter Radius

Volumetric particles use pre-illumination, which evaluates the lighting at each particle’s center by default. This can sometimes cause popping if the illumination changes too fast in an animation, and is especially noticeable if Surface Shading Shadow is on.

Filter radius lets you filter the pre-illumination results so the value at each particle’s center is the average of all the pre-illumination results within the filter radius. Higher values increase render time but produce smoother images.


Next Lecture: [Per Particle Attributes]