Hi George,
I made the turret work from AUM21 Thanks, Thank you

I am trying to create a bone version of the turret, the goal is a single entity, please see this c-script thread. There is a problem when the entity's tilt angle is not zero.
bone problem

Do you plan to have a workshop about bone in one of the next AUM?

I have written two workshops about bones, so I'm afraid that I won't write a new one too soon. You can get the c-script workshops I've written at Conitec's download page (close to the bottom of the page).

Yes I read your bone tutorials when I make my test, and I learn a lot from AUM to create my game.

But my problem is when the model tilt up or down, the bone doesn't look where I point to anymore. If you run my test level in C-script thread you will see, I want a bone_look_at function But these code fail when the model tilt up/down.

Code:

---

vec_for_bone(my.span, me, "bone2");
	vec_diff(temp, player.x, my.span);
	vec_to_angle(my.span, temp);

---

The code looks ok to me. What is the exact angle range where you see the problems?

I post the complete code here
Code:

---

ENTITY* tur;

PANEL modelang  {
	digits(5, 130, "tilt: %f", *, 1, tur.tilt);
	flags = VISIBLE; 
}

view etur1_view = { 		
  layer = 1;
  pos_x = 470;
  pos_y = 360;
  size_x = 130;
  size_y = 100;
  arc = 20;
  aspect = 1;
  ambient = 10;
  fog = 10;
  //genius = null;
  flags = VISIBLE;
}

function main()
{
	video_switch(6,0,2);
	level_load("bonetest.wmb");
	wait(3); // wait until the level is loaded
	//mouse_mode = 2; // now show the pointer

	camera.x = -200;
	camera.z = 100;
	camera.tilt = -25;
}

action turret()
{
	tur = me;
	while (player == NULL) { wait(1); }
	var temp2;

	while (1)
	{
		my.tilt += mouse_force.y;

		vec_for_bone(temp2, me, "bone2");
		vec_diff(temp, player.x, temp2.x);
		vec_to_angle(temp2, temp);

		ent_bonereset(me, "bone1");
		ent_bonereset(me, "bone2");

		//pan
		ent_bonerotate(me,"bone1", vector(temp2.pan, 0, 0));

		//tilt
		ent_bonerotate(me,"bone2",vector(0, temp2.tilt, 0));

		// attach a camera to the front of barrel
		vec_for_vertex(temp, me, 170);
		vec_set(etur1_view.x, temp);
		ang_for_bone(etur1_view.pan, me, "bone2");

		wait(1);
	}
}

action satellite
{
	
	player = me;
	while (tur == NULL) { wait(1); }
	var rotAng = 0;

	while(1)
	{
		rotAng = (rotAng - time_step) % 360;
		my.x = tur.x - 200 * sin(rotAng);
		my.y = tur.y + 200 * cos(rotAng);
		my.z = sin(total_ticks * 5 + 1000) * 80;
		wait(1);
	}
}

---

The model has 2 bones, a satellite move orbit around the entity. I want to Entity constantly look at the satellite, if the entity tilt is 0, everything fine.



But if the entity tilt is non-zero, it cannot look at the satellite correctly. I think because if the entity tilt has change, the bone1 will move bone2, causing the code vec_to_angle not work as expected.



You may download my test project here [35K]: bone.zip

I have tested the demo; if bone1 changes bone2's position indeed, you've got your explanation. Did you try to create the turret using separate model pieces?

Yes I am using separate model pieces now, just want to know the possible solution for bone. Because I am lazy to separate the model and create different set of skin