There are different ways in which you can set the color for particles. You can set the ambient and specular color on the Shading Properties page in any of the three basic shaders’ property editors: Billboard, Blob, and Sphere. You can also add color burn (additivity) for any of these shaders to create specific glow or overexposure effects.
As well, 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 using a gradient control.
Setting the Ambient and Specular Colors
You can set the ambient and specular color for the particles using the parameters on the Shading Properties page in any of the three basic shaders’ property editors (Billboard, Blob, and Sphere).
The ambient color is the shadow color and the specular color is the highlight. The ambient color you set here is modified by the scene’s ambience.
If you turn off Apply Shading, the particles have a constant color and ignore any lights in the scene. If there are no lights in the scene and you turn Apply Shading off, the particles revert to their base color (which will look constant).
To set the ambient and/or specular color
1. Make sure Apply Shading is selected.
2. Do one of the following:
- Select Use Ambient Color and/or Use Specular Color from the appropriate Type list. Set the ambient or specular colors using their associated Color sliders. To get luminescent particles, use a high value for the Ambient color.
You can also set the Shininess of the specular color: low values create a larger specular area.
or
- Select % of Base Color from the appropriate Type list to use a percentage of the particles’ diffuse color that is set for the particle type. Set the percentage using the % of Base slider. To “blast” the color, use values higher than 100%.
The Burn parameter on the Rendering Properties page for the Blob, Billboard, or Sphere shaders adds the RGB values of the particles when they overlap.
This creates a saturated color, or color burn, which is useful for creating glow or radiant, phosphorescent effects. High values can create “inner glow” effects.
Creating Particle Color Gradients (Ramps)
The Particle Gradient shader uses the same gradient controls as found in the Gradient Mixer shader (see Creating Gradients of the Texturing guide) but is designed to be “particle friendly” for color shifts based on a particle’s age. As well, it is optimized for working with a large number of particles. The Particle Gradient shader affects the particle colors from their age percentage by default.
To connect the Particle Gradient shader
• Connect the Particle Gradient shader to the Color node of the Billboard, Sphere, or Blob shader.
or
• Connect the Particle Gradient shader to the Shape or Sprite shader’s Input node, which is, in turn, connected to the Billboard, Sphere, or Blob.
Using the Gradient Controls
The gradient slider in the Particle Gradient shader’s property editor is where you create and adjust the gradient. The bar displays the gradient left-to-right that is used from the particle’s birth (Pos of 0) to its death (Pos of 1).
To select color markers
• Click a square marker below the gradient slider. You can then set its color using the color sliders or key its position.
To set the gradient color/alpha values
1. Do one of the following:
- Select RGB to use only RGB values. You can also select Show alpha to add the alpha channel to the RGB values.
or
- Select Alpha to use only the alpha values.
2. Click a square marker to select the color you want to adjust.
3. Use the color sliders below the gradient control to set the RGB/alpha values to use for this marker.
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Click one of the Presets buttons to load a specific gradient control setup. |
To change the gradient composition
• Drag a color marker anywhere along the gradient.
To insert a color marker
• Click at any point along the gradient slider.
By default, the new marker assumes the color at that point in the gradient. You can use up to eight color markers, each with its own color.
To delete a color marker
• Right-click it and choose Delete marker.
To change the blending between two colors
• Drag a round marker above the gradient slider closer to either square color marker.
Round markers appear between each pair of color markers, indicating the mid-point in the blend between those two colors.
To set the gradient’s interpolation
• Click the Cubic/Linear button to toggle between linear and cubic interpolation of the gradient.
Cubic interpolation results in a smoother transition between alpha values, while linear interpolation results in sharper transitions.
1. Go to the frame at which you want to set keys.
2. Do one of the following:
- Click the Key All RGB/Alpha Markers buttons to key all markers’ positions on the gradient slider (both square and round markers).
or
- Select a square color marker and click the Pos parameter’s animation icon.
To remove the animation on the markers
• At any frame, do one of the following:
- Click the Remove All RGB/Alpha Keys buttons to remove all keys from the markers (both square and round markers).
or
- Select a square color marker and go to a frame where there is a key. Then click the Pos parameter’s animation icon.
To reset the marker positions and remove keys
• Click the Reset Gradient button.
This removes all keys on the RGB and Alpha markers, puts the markers back in their original positions, and disconnects all shaders that are attached to gradient shader parameters.
Overriding the Particle Type’s RGB and/or Alpha Values
You can override the color (and/or alpha values) you’ve set for the particle type by selecting a new color with the Particle Color shader. This is a simple way to keep the particle type’s color constant (such as if you’re using particle types from a library), but change the particle color during rendering
To override the particle color
1. In the render tree, connect the Particle Color shader to the Color inputs on one of the three basic render type shaders (Billboard, Sphere, or Blob).
2. Set the new RGB/alpha values using the New Color color controls.
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