17. Unity particle effects--Renderer module, lighting module, particle system combination, secondary emitter, particle collision, particle trailing

1. Particle orientation (use of Stretched Billboard)

Generally, for particle systems created, the Render Mode selected in the Renderer module is Billboard by default, but in this mode, the direction of the particles is always upward, and sometimes it is hoped that the direction of the head of the particle map is consistent with the emission direction of the particle when it was first generated. You can use the Stretched Billboard mode , and set its stretch ratio (aspect ratio) property Length Scale to 1, as shown in the figure below: Related properties :

Camera Scale: Consider the movement speed of the camera.
Speed ​​Scale: Consider the movement speed of the particles.
Length Scale: The aspect ratio.
At the same time, the head direction of the particle map needs to be set to the left . At this time, the flying direction of the particle is pointed to the head of the particle map Be consistent now.

1.1 Explosion effects

When simulating the explosion of fireworks, after the explosion of the particles, in their own flight direction, the length of the particles is visually stretched to a certain extent, just like when watching fireworks, after the explosion of the fireworks, each particle of the fireworks will have a long strip Effect, this kind of special effect can be realized by using the Speed ​​Scale property above , generally this value is set to a small value, and can be adjusted as needed.
Effect display :