You can also use the particle shaders designed to be used with ICE particles—see ICE Particle Shading for more information.
There are special particle shaders for particle and fluid simulations that give you the control to make particles look the way you want. All particle shaders are texture shaders except for the particle renderer shader, which is a volume shader. As well as these special particle shaders, you can plug many other Softimage shaders into a particle’s render tree.
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You can also use the particle shaders designed to be used with ICE particles—see ICE Particle Shading for more information. |
You can apply shaders to each particle type of a particle cloud for specific multi-effect control. For example, if you have one particle type for smoke and one for lava, you can use a different shader for each one, letting you set the correct look for each entity.
There are different types of particle shaders to give a variety of different effects. Because you can use different particle shaders together, as well as throw other Softimage shaders into the mix, the visual possibilities are virtually endless.
When you create a particle or fluid simulation, the particle renderer shader is connected to the cloud’s Material node by default. As well, with Particle clouds, the Billboard and Shape shaders are connected to the particle type; with Fluid, the Blob shader is connected to the particle type.
To apply other shaders to particles, you connect them in the render tree (see Connecting Shaders in a Particle Render Tree). This gives you more control over which shader is connected to which node. As well, you have access to all other Softimage shaders.
The Particle Renderer Shader on the Cloud
The Particle Renderer shader is a volume shader that acts as a “meta” shader node controlling how the whole particle cloud is rendered. It offers you rendering control with BSP tree settings that are set exclusively for the particle cloud.
This shader plugs in to the particle cloud’s Material node and accepts inputs from other particle shaders via the particle type. This allows for maximum flexibility when you have multiple particle types on the same cloud.
You must have this shader attached to the particle cloud’s Material for particles to be rendered. As well, you must have a basic render type shader (see below) attached to the particle type for particles to be rendered.
The Billboard (2D), Sphere (3D), and Blob (3D) shaders define the basic shape/surface of the particles. You can plug these shaders directly into the particle type or into the Particle Renderer shader that’s on the particle cloud’s material. These shaders are usually used individually on a particle type because they define the basic look of the particles. By default, the Billboard shader is attached to particle types created with the Particle simulator, and the Blob shader is attached to particle types created with the Fluid simulator.
These shaders share many of the same types of parameters for self-shadowing, color burn, global illumination, and shading properties (ambient and specular color settings).
For more information, see The Basic Particle Render Type Shaders.
Texture Shaders
The Sprite and Shape shaders both define the particle’s shape and can be used in combination with each other.
These shaders are 2D-based, so they are often plugged into the Billboard shader, which provides a 2D surface. You cannot plug these color shaders directly into the particle type or cloud.
You can plug them into the Blob and Sphere (3D) shaders, but the results are less predictable because they are 2D non-repeating textures.
For more information, see Rendering Sprites.
Color Shaders
The Particle Color and Particle Gradient shaders both allow you to override the particle type’s color for rendering. The Particle Color shader is a simple shader that overrides RGB/alpha values, while the Particle Gradient shader allows you to create sophisticated color/alpha shifts for the particle.
You can plug the Particle Color and Gradient shaders directly into any of the three basic shaders (Billboard, Blob, or Sphere) or into the Sprite or Shape shaders which are, in turn, plugged into a basic shader. You cannot plug these color shaders directly into the particle type or cloud.
For more information, see Rendering the Particle Color.
The Particle Vector and Particle Scalar shaders let you override the settings for the particle type and output the particle simulation as vector or scalar values. Vector and Scalar shaders allow you to use particle attributes, such as velocity, rotation, particle index, mass, or radius to drive other parameters in the render tree.
You can plug these shaders directly into any of the three basic render type shaders (Billboard, Blob, or Sphere), or into the Sprite, Shape, or Particle Gradient shaders which are, in turn, plugged into a basic shader. You cannot plug these shaders directly into the particle type or cloud.
After you’ve applied a shader, you can edit it by setting the properties in its property editor. First draw a render region over the particles (see next section) to view to results of the shader. Then as you edit the shader’s properties, the render region updates to display the changes you make.
For a description of each parameter in a shader’s property editor, click the ? icon in the property editor to open its online help.
To open a particle shader’s property editor
Do one of the following:
• Select the particle cloud and choose Modify > Shader. This opens the property pages for all shaders attached to the Particle Renderer shader.
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• Select the particle cloud and choose Inspect > Par Types > particle type. This opens the Particle Type property editor, as well as property pages for all shaders attached to this particle type.
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• In a render tree, double-click on the shader’s node to open its property editor, as well as property pages for all shaders attached to it. See Connecting Shaders in a Particle Render Tree for more information.
Previewing Shaders in the Render Region
As you’re tweaking your particles to perfection, you’ll find that the render region is an invaluable friend and ally for checking things. Once you have applied a shader to the particles, you can use the render region to preview a mental ray rendered image of the final look of the particles.
For more information about the render region, see Previewing Interactively with the Render Region [ Rendering ].
To create a render region
• In a viewport, press q and drag over the area of the particles you want to preview.
You can resize the render region using the little blue boxes in its corners or on the sides and set the aliasing by dragging the little slider on the right side of the region.
Autodesk Softimage v.7.5