A particle’s graphic need not be a still image. This module lets you treat the Texture as a grid of separate sub-images that can be played back as frames of animation.
|Tiles||The number of tiles the Texture is divided into in the X (horizontal) and Y (vertical) directions.|
|Animation||The Animation mode can be set to Whole Sheet or Single Row (that is, each row of the sheet represents a separate Animation sequence).|
|Random Row||Chooses a row from the sheet at random to produce the animation. This option is only available when Single Row is selected as the Animation mode.|
|Row||Selects a particular row from the sheet to produce the animation This option is only available when Single Row mode is selected and Random Row is disabled.|
|Frame over Time||A curve that specifies how the frame of animation increases as time progresses.|
|Start Frame||Allows you to specify which frame the particle animation should start on (useful for randomly phasing the animation on each particle).|
|Cycles||The number of times the animation sequence repeats over the particle’s lifetime.|
|Flip U||Horizontally mirror the Texture on a proportion of the particles. A higher value flips more particles.|
|Flip V||Vertically mirror the Texture on a proportion of the particles. A higher value flips more particles.|
|Enabled UV Channels||Allows you to specify exactly which UV streams are affected by the Particle System.|
Particle animations are typically simpler and less detailed than character animations. In systems where the particles are visible individually, animations can be used to convey actions or movements. For example, flames may flicker and insects in a swarm might vibrate or shudder as if flapping their wings. In cases where the particles form a single, continous entity like a cloud, animated particles can help add to the impression of energy and movement.
You can use the Single Row mode to create separate animation sequences for particles and switch between animations from a script. This can be useful for creating variation or switching to a different animation after a collision. The Random Row option is highly effective as a way to break up conspicuous regularity in a particle system (for example, a group of flame objects that are all repeating the exact same flickering animation over and over again). This option can also be used with a single frame per row as a way to generate particles with random graphics. This can be used to break up regularity in a object like a cloud or to produce different types of debris or other objects from a single system. For example, a blunderbuss might fire out a cluster of nails, bolts, balls and other projectiles, or a car crash effect may result in springs, car paint, screws and other bits of metal being emitted.
UV flipping is a great way to add more visual variety to your effects without needing to author additional textures.