HowToC:FollowAnObject

From S2PLOT

Revision as of 23:39, 19 August 2008

How to follow an object with the camera

Using handles, you can easily detect when an object has been right-clicked. With two pretty simple bits of code, you can then make the camera keep focussed on that object.

1. use a handle callback to register the most recently selected handle:

int camfollow; // initialised to -1 in main
unsigned char *selected; // array storing selected state of all handles
void pickcb(int *id) {
  // ...
  // toggle state:
  selected[*id] = (selected[*id] + 1) % 2;
  if (selected[*id]) {
    camfollow = *id;
  } else {
    camfollow = -1;
  }
  s2togglehandle(*id);
}

2. in the standard dynamic callback, set the camera position if required XYZ *iP; // array storing positions of all handles

void callback(double *t, int *kc) {
  // ...

  if (camfollow >= 0) {



  }
}