When a player is looking or clicking at something, they fire a ray that goes until it hits what it needs to hit, or misses.
The result of such a hit is an IRayTraceResult object.

It might be required to import the class to avoid errors.
import crafttweaker.world.IRayTraceResult

All you can do is retrieve information from these objects, here's which:
Be careful though, since all getters that do not return a bool can return null!

name（名称）	类型
name（名称） isMiss	类型 bool
name（名称） isBlock	类型 bool
name（名称） blockPos	类型 IBlockPos
name（名称） sideHit	类型 IFacing

These getters won't actually return anything useful because there isn't a reliable way to raytrace blocks and entities.

name（名称）	类型	return value
name（名称） isEntity	类型 bool	return value always false
name（名称） entity	类型 IEntity	return value always null