The Surface field in the PhysicsTraceResult struct represents the physical properties of the surface that was hit during a physics trace operation. This field provides detailed information about the material characteristics of the surface, which can be used to determine how the surface interacts with other objects, such as friction, restitution, and other material-specific properties.

To access the Surface field, you need to perform a physics trace operation and obtain a PhysicsTraceResult instance. Once you have the result, you can access the Surface field to get information about the hit surface's physical properties.

Example usage:

PhysicsTraceResult traceResult = PerformPhysicsTrace();
if (traceResult.Hit)
{
    Surface hitSurface = traceResult.Surface;
    // Use hitSurface to determine material properties
}