Use markers to control camera position?

[Zoe Woodworth]

Is it possible to control a camera’s position based on what the current comp marker is?

For example, imagine a comp with 25 markers. All the markers have one of three names: “Wide” , “John” , and “Justin”. Any time that we encounter a “Wide” marker, I want to set the active camera position to x,y,z. Any time we encounter a “John” marker, I want to change the camera position to a,b,c… and so on.

If I could do something like this, it would save me SO much time from having to copy and paste keyframes manually!

Any help would be greatly appreciated!

[Dan Ebberts]

Something like this should work:


widePos = [200,100,0];
johnPos = [100,200,0];
justinPos = [300,200,0];

C = thisComp;
n = 0;
if (C.marker.numKeys > 0){
n = C.marker.nearestKey(time).index;
if (C.marker.key(n).time > time){
n--;
}
}
if (n > 0){
if (C.marker.key(n).comment.toLowerCase() == "wide"){
widePos;
}else if(C.marker.key(n).comment.toLowerCase() == "john"){
johnPos;
}else if(C.marker.key(n).comment.toLowerCase() == "justin"){
justinPos;
}else{
value;
}
}else{
value;
}


Dan

[Zoe Woodworth]

Woo hoo! Thank you Dan! You have no idea how much easier that makes my life :).

[Zoe Woodworth]

Follow-up question: Could this be done with layer markers, instead of composition markers? Could the expression refer to such-and-such layer’s markers?

[Dan Ebberts]

Sure. The simplest way would probably just be to change this:

C = thisComp;

to this:

C = thisComp.layer(“your layer”);

If it were me, I’d probably also change the variable name to “L” (because it now represents a layer instead of a comp) and change “C.” to “L.” everywhere in the expression.

Dan

[Scott Green]

Can you tell me where you place these expressions to get this to work please?

On the camera Position?

And are those first set of expressions meant to be on top of the second set? This isn’t working for me, yet.

Thanks.

[Dan Ebberts]

Yes, the expression goes on the camera’s position property. I’ve cleaned it up a little:

Pos01 = [200,100,0];
Pos02 = [100,200,0];
Pos03 = [300,200,0];
m = thisComp.marker;
n = 0;
if (m.numKeys > 0){
  n = m.nearestKey(time).index;
  if (m.key(n).time > time) n--;
}
if (n > 0){
  if (m.key(n).comment == "Pos01"){
    Pos01;
  }else if(m.key(n).comment == "Pos02"){
    Pos02;
  }else if(m.key(n).comment == "Pos03"){
    Pos03;
  }else{
    value;
  }
}else{
  value;
}

[Scott Green]

That works, thanks Dan. I did however think that this was a way of moving/easing from one camera to the next rather than jumping from one to the other. It is possible to move from one camera to the next using this method?

[Dan Ebberts]

Something like this, maybe:

Pos01 = [200,100,0];
Pos02 = [100,200,0];
Pos03 = [300,200,0];
moveTime = 0.3;
m = thisComp.marker;
n = 0;
if (m.numKeys > 0){
  n = m.nearestKey(time).index;
  if (m.key(n).time > time) n--;
}
if (n > 0){
  t1 = m.key(n).time;
  t2 = t1 + moveTime;
  if (m.key(n).comment == "Pos01"){
    ease(time,t1,t2,valueAtTime(t1),Pos01);
  }else if(m.key(n).comment == "Pos02"){
    ease(time,t1,t2,Pos01,Pos02);
  }else if(m.key(n).comment == "Pos03"){
    ease(time,t1,t2,Pos02,Pos03);
  }else{
    value;
  }
}else{
  value;
}

[Scott Green]

Nice! Linking the moveTime to a slider control to change the movement speed and pick whipping the positions to the position of my comps works really well too. Thanks Dan.