Amazon Sumerian
User Guide

Amazon Sumerian Particle System Component

The particle system component simulates fluid entities such as liquids, clouds, and flames by generating and animating large numbers of small 2D images in the scene.

Properties

  • General – The basic behavior of the particle emitter.

    • Auto play – Start the emission animation when the scene starts.

    • Loop – Loop the animation.

    • Duration – Duration of the animation in seconds.

    • Prewarm – Load the effect prior to playback.

    • Max particles – Limit the number of visible particles.

    • Gravity – Vector of the gravity force that applies to particles.

    • Seed – Randomization seed. Experiment with values to find a look that you like, or set to -1 to get a different effect each time.

    • Local space simulation – Set to true to simulate the particle system within the boundaries of the parent entity, instead of in the entire scene.

  • Emitter shape – The shape and size of the emitter. Additional settings are specific to each shape.

    Box

    • Random direction – Emit each particle in a random direction.

    • Box extents – The height, width, and length of the emitter.

    Sphere

    • Radius – The size of the emitter.

    • Emit from shell – Emit particles from the outside edge of the emitter.

    • Random direction – Emit each particle in a random direction.

    Cone

    • Random direction – Emit each particle in a random direction.

    • Emit from – Emit particles from the narrow end of the cone (Base), the center of the cone (Volume), or the edges of the cone (Volumeedge).

    • Cone radius – The radius of the cone at the narrow end.

    • Cone angle – The angle at which the sides of the cone flare out.

    • Cone length – The length of the sides of the cone.

  • Over duration properties – Fine tune values that apply to each loop of animation. Each value can be constant, or progress linearly or randomly over the duration.

    • Emission rate – The number of particles emitted per second.

    • Start speed – The speed of the particles.

    • Start size – The size of the particles.

    • Start color – The color of the particles.

    • Start life time – The number of seconds before each particle disappears.

    • Start angle – The angle of particles.

  • Over lifetime properties – Fine tune values that apply to the entire lifetime of the particle emitter. Each value can be constant, or progress linearly or randomly over the lifetime.

    • Color – The color of the particles. Compounds with the duration color.

    • Size – The size of the particles. Compounds with the duration size.

    • Rotation speed – Rotation of particles in degrees per second.

    • Local velocity – Local space velocity in units per second.

    • World velocity – World space velocity in units per second.

  • Texture – The texture of each particle. Use one of the provided textures or choose custom to upload a texture.

  • Texture animation

    • Texture tiles – The number of tiles in the sprite sheet, in X and Y directions.

    • Cycles – The number of texture animation cycles to finish over the lifetime.

    • Frame over lifetime – A curve specifying when to show which frame in the animation. 0 is the first frame and 1 is the last. A linear curve starting at 0 and ending at 1 traverses all frames in the animation.

  • Rendering – Customize the rendering behavior.

    • Billboard – Particles always face the camera.

    • Render queue – Render queue of the particle mesh.

    • Render queue offset – Offset added to the render queue.

    • Blending – The type of blending (None, Additive, Subtractive, Multiply, or Transparency).

    • Depth write – Write to the depth buffer.

    • Depth test – Test against the depth buffer.

    • Sorting mode – The draw order for particles (None or Camera distance). For transparency blending, camera distance sorting is recommended.

    • Opacity threshold – The lower alpha threshold at which fragments are discarded.