Particle System 2026-05-26 Updated

Reasons why Particle System's transparent expression looks strange in URP and material settings

Difficulty Intermediate

Unity Version Unity 2022.3 LTS / Unity 6 対応

Target Audience VFX designer, effects artist, TA

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Symptom

When playing the effect in a URP environment, the transparent parts of particles are drawn as black squares. Or, areas where particles overlap may become blown out, or effects in the background may show through in the foreground.

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Root Cause

The cause is that the old particle shader for the built-in pipeline is still being used, or the Surface Type of the URP material remains Opaque, or Depth Write is enabled and the drawing order (Sorting) is broken.

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Solution

Convert the particle material shader to "Universal Render Pipeline/Particles/Unlit" and set the Surface Type to Transparent. Set the blend mode to Alpha (or Additive) and make sure to set "Depth Write -> Off", which is essential for translucent drawing.

When migrating a project from the legacy (Built-in) pipeline to the URP (Universal Render Pipeline), particles (effects) are most likely to be the first to break.

Specific solution

This is the complete "correct setting" for particle materials in URP.

1. Change the shader to URP only.

Select the following from the material's Shader pull-down.

Universal Render Pipeline ➔ Particles ➔ Unlit

2. Adjust Surface Options

Surface Type: Change to Transparent (translucent)
Blending Mode: Select according to the effect you want to express (Alpha / Additive)

Conceptual diagram of Opaque and Transparent drawing order and depth buffer control in Unity URP translucent rendering

Figure 1: Opaque -> Transparent drawing order and Depth Write Off mechanism in translucent drawing queue (Transparent)