Particles are normally rendered using the same techniques as other polygons in the game world, such as Alpha, Additive, Multiply and Inverse modulate blends. Each of these blend modes has uses that are important to understand.
A standard alpha-blended particle retains its color on any play surface, which can be used to one’s advantage. This makes it ideal for use as a fill particle within an effect as it will block visibility of the game behind it. A typical use of this technique is found in smoke and dirt cloud particles.
Additive- and multiply-blended particles are translucent and do not block visibility but have other important uses. Additive particles bring the color of the background scene pixel closer to white by the brightness value of the texture. This quality makes additive blending the choice for rendering fire or energy plasmas.
Multiply-blended textures are similar to additive except that they darken the color of the background pixel by the brightness value of the texture. Multiply-blended textures also invert the color they multiply by. An example is a particle texture of a bright orange dot on a black background – this will darken the scene with a dark blue dot, which darkens more the brighter the orange dot is.
Inverse 2X modulate-blended particles invert the background pixel color by the brightness value of the texture. This special case shader is best used in stylized or non-realistic effects as small details. If this technique is used on a gray surface, the effects will be almost unnoticeable as the inverse of gray is still gray. Sorting above other parts of an effect can allow for a more noticeable color inversion.