If you are asking about the concept of "normal" I might can explain that a little bit.

Normal basically means perpendicular. So the surface normal is a vector (like a line) that extends from a surface at a 90 degree angle.

Hmm, pictures would help I guess.

Imagine you have a surface representing a horizontal floor. The normal to the floor would be a vertical vector.

^
| <-- This vector is normal to the floor
|
_________ <-- This is suppose to be the floor

Or is you had a vertical wall, then normal to the wall would be a horizontal vector.

| <--This is the wall
|
|-----> This vector is normal to the wall
|
|

of course you can have a normal to any surface at any angle, these are just the simplest examples. Maybe that will help some, I hope.

so the normal is 90 degrees all around the surface it is perpendiculat to? What exactly do you mean the vector is perpendicular to the surface? How is i perpendiculat ? you mean the values .x .y .z? or .tilt .pan . roll?

I am making a race car bot and i want it to trace 100 quants ahead of it all the time and if it finds a wall to turn to the angle of that wall (be parallel to it), so i have this in a loop with a wait(1) at the end:

trace_mode = ignore_passable + ignore_models;
trace_to.x = my.x + (100 * cos(my.pan));
trace_to.y = my.y + (100 * sin(my.pan));
the_result = trace(my,trace_to);
if (the_result != 0) // if it found a wall
{
vec_to_angle(the_result_angle.pan, normal);
my.pan = the_result_angle.pan + 90;
}

then under that i have the code to move it foward according to its pan. It doesnt work. Can any one help?