Texture Sheet Animation module

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.

Grid mode properties

PropertyA generic term for the editable fields, buttons, checkboxes, or menus that comprise a component. An editable property is also referred to as a field. More info See in Glossary	Function
Mode popup	Select Grid mode.
TilesA simple class that allows a sprite to be rendered on a Tilemap. More info See in Glossary	The number of tiles the Texture is divided into in the X (horizontal) and Y (vertical) directions.
AnimationA collection of images that create a moving image when played sequentially. In Unity, an animation is the result of adding two different animation keys, at two different times, for the same animatable property. More info See in Glossary	The Animation mode can be set to Whole Sheet or Single Row (that is, each row of the sheet represents a separate Animation sequence).
Time Mode	Choose how the Particle SystemA component that simulates fluid entities such as liquids, clouds and flames by generating and animating large numbers of small 2D images in the scene. More info See in Glossary samples frames in the animation.
Lifetime	Sample frames using an Animation CurveThe curve drawn between keys set for the same animatable property, at different frames or seconds. The position of the tangents and the selected interpolation mode for each key determines the shape of the animation curve. More info See in Glossary over the lifetime of the particle.
Speed	Sample frames based on the speed of the particle. A speed range specifies the minimum and maximum speed range for the frame selection.
FPSSee first person shooter, frames per second. See in Glossary	Sample frames based on the specified frames-per-second value.
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.
Affected UV Channels	Allows you to specify exactly which UV streams are affected by the Particle System.

Sprite mode properties

Property	Function
Mode popup	Select SpritesA 2D graphic objects. If you are used to working in 3D, Sprites are essentially just standard textures but there are special techniques for combining and managing sprite textures for efficiency and convenience during development. More info See in Glossary mode.
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.
Enabled UV Channels	Allows you to specify exactly which UV streams are affected by the Particle System.

Details

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, continuous 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 collisionA collision occurs when the physics engine detects that the colliders of two GameObjects make contact or overlap, when at least one has a rigidbody component and is in motion. More info
See in Glossary. 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.

Selecting the Sprites option from the Mode dropdown allows you to define a list of Sprites to be displayed for each particle, instead of using a regular grid of frames on a texture. Using this mode allows you to take advantage of many of the features of Sprites, such as the Sprite PackerA facility that packs graphics from several sprite textures tightly together within a single texture known as an atlas. Unity provides a Sprite Packer utility to automate the process of generating atlases from the individual sprite textures. More info
See in Glossary, custom pivots and different sizes per Sprite frame. The Sprite Packer can help you share materials between different Particle Systems, by atlasing your textures, which in turn can improve performance via Dynamic BatchingAn automatic Unity process which attempts to render multiple meshes as if they were a single mesh for optimized graphics performance. The technique transforms all of the GameObject vertices on the CPU and groups many similar vertices together. More info
See in Glossary. There are some limitations to be aware of with this mode. Most importantly, all Sprites attached to a Particle System must share the same texture. This can be achieved by using a Multiple Mode Sprite, or by using the Sprite Packer. If using custom pivot points for each Sprite, please note that you cannot blend between their frames, because the geometry will be different between each frame. Only simple Sprites are supported, not 9 slice. Also be aware that MeshThe main graphics primitive of Unity. Meshes make up a large part of your 3D worlds. Unity supports triangulated or Quadrangulated polygon meshes. Nurbs, Nurms, Subdiv surfaces must be converted to polygons. More info
See in Glossary particles do not support custom pivots or varying Sprite sizes.

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• 2018–10–19 Page amended with limited editorial review

• Functionality of Texture Sheet Animation module changed in Unity 2017.1 NewIn20171

• Time Mode added to Particle System in Unity 2018.3 NewIn20183