I'm adding some particle trails to projectiles in my game Fortifend (please excuse the placeholder texture):
I created a GPUParticles3D node for this purpose. When I call the emit_particle() function, I can set the origin point and velocity of the particle.
At the time of creation, I know how long it will take for the projectile to reach its target. So I can set the lifetime of the trail particle to this value using the 4th channel of the custom color passed to emit_particle(). This makes the trail wink out of existence exactly when the target is struck, which looks bad.
Is there any way to make the trail fade out cleanly? I also want to avoid the trail particle penetrating past the target, because then it would sometimes be seen passing through the terrain.
Thanks in advance for anyone who can help!