The Trail Renderer component renders a trail of polygons behind a moving GameObject, over time. This can be used to give an emphasized feeling of motion to a moving object, or to highlight the path or position of moving objects.
The Trail Renderer uses the same algorithm for trail rendering as the Line RendererA component that takes an array of two or more points in 3D space and draws a straight line between each one. You can use a single Line Renderer component to draw anything from a simple straight line to a complex spiral. More info
See in Glossary.
The Min Vertex Distance value determines how far in world units the GameObject to which the trail applies must travel before a new segment is added to the trail. Low values like 0.1 create trail segments more often, creating smoother trails. Higher values like 1.5 create segments that are more jagged in appearance. Additionally, wide trails may exhibit visual artifacts when the vertices are very close together and the trail changes direction significantly over a short distance.
For performance reasons, it is best to use the largest possible value that achieves the effect you are trying to create.