Hey,

This may be a trivial problem, but I can't seem to get it to work out for me..

I have written my own 3rd person camera system, and I need to detect the z-value of the ground below the camera. This way, I can move the camera a set distance above the ground to avoid the camera going under the terrain.

I had tried using c_trace like I had done with my player, but I think I was missing something because the camera behaved sporadically.

It's been stumping me for a little while now, so I'm just hoping that a more seasoned coder than myself could help me out.

Thanks,

I figured it out, I just needed to create a temporary vector to represent the camera position.. That seems to be too jumpy though...

Back to the drawing board I suppose..

Thanks,

c_trace sounds like a good way to go could u post us a snippet so we might be able to figure out how to smoothen it for you?

julz

Code:

---

int cam_height = 100;

VECTOR ground;
VECTOR temp_cam;
		
vec_zero(ground);
vec_zero(temp_cam);

temp_cam.x = camera.x;
temp_cam.y = camera.y;

vec_set(ground, temp_cam.x);
		
ground.z -= 10000;
		
trace_mode = IGNORE_ME + IGNORE_PASSABLE + USE_BOX;
		
ground.z = -c_trace(temp_cam.x,ground,trace_mode);

camera.z = ground.z + cam_height;

---

I think that the reason it's jumpy is because the height of the terrain changes sporadically depending on the slope and even though I am setting USE_BOX the camera isn't very 'fat.'

So if there was some way I could make the camera 'fatter' so that it's collision box would be bigger, I think that that would help.

Thanks for your reply ,

i think USE_BOX depends on the bounding box of the entity calling the c_trace, so if this is called by another entity (whoever the "my" pointer points to), the box will be based on that entity's shape. if it is a standalone function with no "my" pointer -- well, the camera doesn't have a bounding box afaik.

you could get the difference between the camera's current z and its new z, and average it out. this way, the camera should smoothly move between the different heights instead of instantly going to the new height.

hope this helps

julz

That just might work, I'll try to work on that as soon as I get a chance, and I'll post a snippet if I get it to work out properly.

Thanks a lot for your input, I think it may have been just what I needed

Code:

---

var cam_height = 350;

VECTOR temp_ground;
VECTOR temp_cam;

vec_zero(temp_ground);
vec_zero(temp_cam);

temp_cam.x = camera.x;
temp_cam.y = camera.y;

vec_set(temp_ground, temp_cam.x);

temp_ground.z -= 10000;

trace_mode = IGNORE_ME + IGNORE_PASSABLE;

temp_ground.z = c_trace(temp_cam.x,temp_ground,trace_mode);

if((temp_ground.z + cam_height) != camera.z)
{
	if(camera.z < (temp_ground.z + cam_height))
	{
		camera.z += (5 * time_step);
		if(camera.z > (temp_ground.z + cam_height))
			camera.z = temp_ground.z + cam_height;
	}
	
	else
	{
		camera.z -= (5 * time_step);
		
		if(camera.z < (temp_ground.z + cam_height))
			camera.z = temp_ground.z + cam_height;
		
	}
}

---

It works

Thanks for your idea!!

cool no problem!