I am making a "Don't touch the spikes" remake in unity C#. I want to make the effect of the dots behind the bird like in the image below. How can I do this?
Unity has a readily available Trail Renderer. That's all you need. The Trail Renderer is used to make trails behind objects in the scene as they move about. From the source:
The Trail Renderer is great for a trail behind a projectile, or contrails from the tip of a plane’s wings. It is good when trying to add a general feeling of speed.
When using a Trail Renderer, no other renderers on the GameObject are used. It is best to create an empty GameObject, and attach a Trail Renderer as the only renderer. You can then parent the Trail Renderer to whatever object you would like it to follow.
In other words, it is best to create a child object and add TrailRenderer component to it instead of adding directly to the main game object.
You will need to create a particle prefab with the small circles as the image that get more transparent and smaller as they travel away. There's quite a lot more to it than that but to go into I feel would take an extremely long answer. Maybe when I get home and can take screenshots but there are a lot of tutorials on the particle system that would probably do a better job than me