Renderer

The renderer module is used to generate the data needed for particle rendering.

Property	Description
RenderMode	Set a particle patch generation method. Billboard particles always face the camera StretchedBillboard particles always face the camera, but will be stretched according to the relevant parameters HorizontalBillboard particles patches are always in the x-z plane parallel VerticalBillboard particles patch is always parallel to the Y axis, but will face the camera Mesh particles are a model.
VelocityScale	In stretchedBillboard mode, the particles are stretched according to the speed in the direction of motion.
LengthScale	In StretchedBillboard mode, the particles are stretched by the size of the particles in the direction of motion.
Mesh	When RenderMode is set to Mesh, specify the model of particles to be rendered.
ParticleMaterial	The material used for particle rendering. When use the CPU renderer, that is, when UseGPU option is not selected, the effect used by the material can only be builtin-particle, and other effects are not supported. When use the GPU renderer, that is, when UseGPU option is checked, the effect used by the material can only be builtin-particle-gpu, and other effects are not supported.
TrailMaterial	The material used for trail rendering. The effect of the material only supports builtin-particle-trail, not other effects.
UseGPU	Whether to use the GPU renderer for particle rendering, it is not selected by default. When this option is not checked, use the CPU renderer ParticleSystemRendererCPU to render particles. When this option is checked, use the GPU renderer ParticleSystemRendererGPU to render particles.
AlignSpace	Particle alignment space, options include View (default), World and Local, selecting different spaces will determine the initial particle orientation: When View is selected, the rotation direction of the particle mesh will follow the camera's view direction. When World is selected, the direction of the particle mesh will use the world space rotation direction of the emitter node. When Local is selected, the particle mesh will use the local space rotation direction of the emitter node.

Particle Renderer

The particle rendering part is controlled by ParticleSystemRenderer, which is divided into CPU renderer and GPU renderer.

The CPU renderer maintains all particles through an object pool, generates corresponding vb and ib data according to the current state of the particles, holds the materials to be rendered by the particles, and saves the relevant rendering state.

The GPU renderer generates particles on the CPU side, and only submits the vb and ib data of initial parameter, but the calculations related to the module are in the form of pre-sampled data. The data is submitted once during initialization, and the subsequent module system extracts and simulates the data on the GPU side to reduce the computing pressure on the CPU side. The subsequent versions will continue to optimize and improve the particle system. The current GPU version does not support TrailModule and LimitVelocityOvertimeModule.