UeParticleRenderer

UeParticleRenderer is an optimized renderer that uses vertex batching and dedicated shaders to draw thousands of particles with billboarding in a single draw call.

Constructor

var renderer = new UeParticleRenderer();

Methods

render

Draws the specified particle system.

renderer.render(system, camera, [texture], [isShadowPass]);

• system: The particle system to render.
• camera: The camera for billboarding (needed to get Right and Up vectors).
• texture: (Optional) Texture to use. Default: sprUiPointLight.
• isShadowPass: (Optional) Whether this is a depth-only pass for shadow casting.

dispose

Frees the resources (vertex buffer) used by the renderer.

renderer.dispose();

Shaders

sh_ue_particle

The main shader handles:

1. Billboarding: Calculated on the GPU using camera vectors.
2. Soft Particles: Fades particles when they intersect scene geometry using the depth buffer.
3. Shadow Receiving: Samples the directional shadow map to apply shadows to particles.
4. Alpha Testing: Discards transparent pixels for depth-buffer optimization.

sh_ue_particle_shadow

A specialized depth-only shader used for shadow casting. It maintains billboarding and alpha testing to ensure shadows match the particle's shape.

Integration Example

// In Draw Event
gpu_set_zwriteenable(false); // Disable z-write for transparent particles
gpu_set_blendmode(bm_add);    // Optional: additive blending

particleRenderer.render(particleSystem, mainCamera);

gpu_set_blendmode(bm_normal);
gpu_set_zwriteenable(true);