walking on terrain with 4 legs

ent_terrain = you;
	burro = me;
	vec_set(temp, you.x);
	vec_sub(temp,my.x);
        my.tilt = vec_to_angle(you.tilt,temp);

VECTOR front;
VECTOR back;
// Calculate front position
vec_set(front, vector(10, 0, 0)); // Distance 10 from model center
vec_rotate(front, vector(my.pan, 0, 0));
vec_add(front, my.x);
front.z += 100;

// Calculate back position
vec_set(back, vector(-10, 0, 0)); // Distance 10 from model center
vec_rotate(back, vector(my.pan, 0, 0));
vec_add(back, my.x);
back.z += 100;

var h1 = c_trace(back, vector(back.x, back.y, back.z - 200), IGNORE_ME | IGNORE_PASSABLE | ...);
var h2 = c_trace(front, vector(front.x, front.y, front.z - 200), IGNORE_ME | IGNORE_PASSABLE | ...);

var dist = h2 - h1;
my.tilt = atanv(dist / 20); // 20 is the distance between the front and the back vector before rotating and so

// Calculate rotation
VECTOR *front = vector(32, 0, 0);   // Fron location
// Rotate front relative to the entity
vec_rotate(front, vector(my.pan, 0, 0)); // Take into account only pan angle
		
VECTOR trace_pos;   // The trace position
		
// Do a first trace for  the front legs
vec_set(trace_pos, my.x);
vec_add(trace_pos, front);
var front_trace = c_trace (trace_pos, vector(trace_pos.x, trace_pos.y, trace_pos.z - 10000), IGNORE_ME | IGNORE_PASSABLE);
				
		
// Do a second trace for the rear legs
VECTOR *rear = vector(0, 0, 0);
vec_set(rear, front);

// reverse x direction
rear.x *= -1;
vec_set(trace_pos, my.x);
vec_add(trace_pos, rear);
var rear_trace = c_trace (trace_pos, vector(trace_pos.x, trace_pos.y, trace_pos.z - 10000), IGNORE_ME | IGNORE_PASSABLE);
		
// Calculate the tilt based on the traces pos
var delta = front_trace - rear_trace;
var dist = 64; // 64 (size of the animal)
var tilt_angle = -atan2v(delta, dist);
my.tilt = tilt_angle;

action follow_player
{ 
	while(player == 0){wait(1);} 
	c_setminmax(me);
	temp.z -= 10000;
	my.z -=c_trace(my.pos,temp,use_polygon|ignore_me|ignore_passable|ignore_passents)-9;
	my.health = 100;//I've got 100 Healthpoints 
	my.shadow = on;
	my.cast = on;
	mat_shadow.alpha = 60;
	while (my.health > 0)//as long as I live 
	{
		if (vec_dist (my.x, player.x) < 500 && player.health > 0)		
			{   
				vec_set(temp, player.x);    
				vec_sub(temp, my.x);   
				vec_to_angle(my.pan, temp);   
				vec_set (temp, my.x);   
			}  
		if (vec_dist (my.x, player.x) > 60)//&&(mouse_right == 1)  
			{   
				vec_set(temp, player.x);    
				vec_sub(temp, my.x);   
				vec_to_angle(my.pan, temp); 
				temp.z -= 10000;
				my.z -=c_trace(my.pos,temp,use_polygon|ignore_me|ignore_passable|ignore_passents)-9;
				walk_percent = (walk_percent +12*time_step*player_speed_land_walk)%100;
				ent_animate(me,"walk",walk_percent,anm_cycle);
				c_move(me,vector(2*time_step,0,0),vector(0,0,my.PlayerGravity),glide|ignore_me|ignore_passable|ignore_passents); 
			}  
		if (vec_dist (my.x, player.x) < 500)&&(mouse_right != 1) 
			{
			temp.z -= 10000;
			my.z -=c_trace(my.pos,temp,use_polygon|ignore_me|ignore_passable|ignore_passents)-9;
			stand_percent = (stand_percent +0.05*time_step)%100;
			ent_animate(me,"stand",stand_percent,anm_cycle);
			}
	wait(1);
	}  
}

function test
{	
  vec_set(temp, my.x);
 	temp.z -= 1000; // 1000 Quants down
 	c_trace(my.x, temp, IGNORE_ME); 
 	vec_set(my.x, target);
 	vec_to_angle(my.pan, normal); // put on surface
}