[Daniel Cantwell]

Thanks everyone for your suggestions. Walter, you sir, are a legend! Worked a treat! All the best and many thanks.

[Daniel Cantwell]

Hi Dave

Thanks for your reply. I have two sources.

1. A live action plate of a subject walking left to right with tracking markers. The track is 28 feet.

2. A scale model at 1-18 scale. The camera is motion controlled, so it can shoot at very precise intervals giving a linear camera move with no ramp up or down in speed and a heavy overlap of frames over the move, say 800 frames. The camera is a stills camera. The distance from the live action can be divided by 18 giving the scale model length so the distance is correct. I am looking for a way to control the frame rate of the 800 frames with the speed curve of the track to give the correct ramp up and down in speed given the distance is accurate.

Yes there are a lot of other ways of doing this. For instance the BG could be stitched and the various BG assets could be put on 2.5d planes with a virtual camera giving parallax or the BG could be photogrammetry and again a virtual camera used. Really this is just to satisfy my curiosity it could be done with an expression. Theoretically it seems like it should be possible.

All the best

[Daniel Cantwell]

No problem Jim, glad I could help. ????

[Daniel Cantwell]

Hey Jim

Sorry for not explaining myself better. I’ve made a video which will hopefully clear things up.

https://f1.creativecow.net/file/11197/11197_elbowcontrolduikhd.mp4.zip

Let me know if you have any problems.

Thanks.

Daniel

[Daniel Cantwell]

Hey! I know this was posted a while ago but I’m going to put up the solution I’ve found as I was looking this morning for an answer to this and there is very little on the interwebs about it. If you make a regular IK Chain,ie. puppet pin you arm in shoulder,elbow and wrist, select the layer and hit bones, parent wrist to elbow and elbow to shoulder click your wrist null and create a controller for it, select shoulder,elbow,wrist nulls along with wrist controller and hit IK. Once this is complete and you have a normal ik chain, duplicate the elbow controller and rename it elbow manipulator or whatever you want. Delete all the Ik in the effects panel, rotation and position and then match the position and rotation of the original elbow controller. Select your new elbow controller go to solid settings and make it twice as big pixel wise as your original so you can easily differentiate between the two. Parent this new controller to the original elbow controller with all the ik junk in it. Go into your puppet pins on your arm and in the elbow puppet pin rename the target in the expressions from the original elbow controller to your new one. Now you will still have all your original IK functionality with the addition of being able to freely move the elbow. Hope this helps.

[Daniel Cantwell]

Hi Dan

I understand it now. I’ve been working on a rig for days and for some reason I was thinking comp width was 1080 instead of 1920 like a dope so i couldn’t understand the expression. I’ve got it perfectly now thanks a lot for your help. I modified it for a 6000 comp connected to a null for a faux 3d Rig body rotation. It works great!

All the best

Daniel

x = thisComp.layer("BODY_ROTATION").transform.position[0];
if(x>1340 && x<1400){
}else if(x>-68 && x<644){
}else if(x>-1430 && x<-768){
[100];
}else{ [0] ; }

[Daniel Cantwell]

Hi Dan

I figured out with the help of your expression how to get what I was looking for. The expression will probably make your eyes burn but here it is.

Many thanks

Daniel

p = thisComp.layer("Null 1").position;
d = p[0] - thisComp.width/2;
if (d>0 && d<200)
  value + [d,0]
else if (d < 0 && d > -200)
  value - [d,0]
else if ( d < -199 && d > -400)
 value + [d - 400,0]+800
else if ( d > 199 && d < 400)
  value - [d - 400,0]
else
  value + [0,0]

[Daniel Cantwell]

Hi Dan. First off thanks so much for replying, I’m a big fan. This expression works great! I was trying to push it a little further by having the same motion happen again when the Null goes to the left of the centre but I cant figure out how to structure the if else statements. I’ll keep looking but if you had the time I would be grateful if you could cast some light on it.

All the best

Daniel